# Code examples for Lambda using AWS SDKs
<a name="service_code_examples"></a>

The following code examples show how to use Lambda with an AWS software development kit (SDK). 

*Basics* are code examples that show you how to perform the essential operations within a service.

*Actions* are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.

*Scenarios* are code examples that show you how to accomplish specific tasks by calling multiple functions within a service or combined with other AWS services.

*AWS community contributions* are examples that were created and are maintained by multiple teams across AWS. To provide feedback, use the mechanism provided in the linked repositories.

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

**Contents**
+ [Basics](service_code_examples_basics.md)
  + [Hello Lambda](example_lambda_Hello_section.md)
  + [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md)
  + [Actions](service_code_examples_actions.md)
    + [`CreateAlias`](example_lambda_CreateAlias_section.md)
    + [`CreateFunction`](example_lambda_CreateFunction_section.md)
    + [`DeleteAlias`](example_lambda_DeleteAlias_section.md)
    + [`DeleteFunction`](example_lambda_DeleteFunction_section.md)
    + [`DeleteFunctionConcurrency`](example_lambda_DeleteFunctionConcurrency_section.md)
    + [`DeleteProvisionedConcurrencyConfig`](example_lambda_DeleteProvisionedConcurrencyConfig_section.md)
    + [`GetAccountSettings`](example_lambda_GetAccountSettings_section.md)
    + [`GetAlias`](example_lambda_GetAlias_section.md)
    + [`GetFunction`](example_lambda_GetFunction_section.md)
    + [`GetFunctionConcurrency`](example_lambda_GetFunctionConcurrency_section.md)
    + [`GetFunctionConfiguration`](example_lambda_GetFunctionConfiguration_section.md)
    + [`GetPolicy`](example_lambda_GetPolicy_section.md)
    + [`GetProvisionedConcurrencyConfig`](example_lambda_GetProvisionedConcurrencyConfig_section.md)
    + [`Invoke`](example_lambda_Invoke_section.md)
    + [`ListFunctions`](example_lambda_ListFunctions_section.md)
    + [`ListProvisionedConcurrencyConfigs`](example_lambda_ListProvisionedConcurrencyConfigs_section.md)
    + [`ListTags`](example_lambda_ListTags_section.md)
    + [`ListVersionsByFunction`](example_lambda_ListVersionsByFunction_section.md)
    + [`PublishVersion`](example_lambda_PublishVersion_section.md)
    + [`PutFunctionConcurrency`](example_lambda_PutFunctionConcurrency_section.md)
    + [`PutProvisionedConcurrencyConfig`](example_lambda_PutProvisionedConcurrencyConfig_section.md)
    + [`RemovePermission`](example_lambda_RemovePermission_section.md)
    + [`TagResource`](example_lambda_TagResource_section.md)
    + [`UntagResource`](example_lambda_UntagResource_section.md)
    + [`UpdateAlias`](example_lambda_UpdateAlias_section.md)
    + [`UpdateFunctionCode`](example_lambda_UpdateFunctionCode_section.md)
    + [`UpdateFunctionConfiguration`](example_lambda_UpdateFunctionConfiguration_section.md)
+ [Scenarios](service_code_examples_scenarios.md)
  + [Automatically confirm known users with a Lambda function](example_cross_CognitoAutoConfirmUser_section.md)
  + [Automatically migrate known users with a Lambda function](example_cross_CognitoAutoMigrateUser_section.md)
  + [Create a REST API to track COVID-19 data](example_cross_ApiGatewayDataTracker_section.md)
  + [Create a REST API with Lambda proxy integration](example_api_gateway_GettingStarted_087_section.md)
  + [Create a lending library REST API](example_cross_AuroraRestLendingLibrary_section.md)
  + [Create a messenger application](example_cross_StepFunctionsMessenger_section.md)
  + [Create a serverless application to manage photos](example_cross_PAM_section.md)
  + [Create a websocket chat application](example_cross_ApiGatewayWebsocketChat_section.md)
  + [Create an application to analyze customer feedback](example_cross_FSA_section.md)
  + [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md)
  + [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md)
  + [Invoke a Lambda function from a browser](example_cross_LambdaForBrowser_section.md)
  + [Transform data with S3 Object Lambda](example_cross_ServerlessS3DataTransformation_section.md)
  + [Use API Gateway to invoke a Lambda function](example_cross_LambdaAPIGateway_section.md)
  + [Use Step Functions to invoke Lambda functions](example_cross_ServerlessWorkflows_section.md)
  + [Use scheduled events to invoke a Lambda function](example_cross_LambdaScheduledEvents_section.md)
  + [Use the Neptune API to query graph data](example_cross_Neptune_Query_section.md)
  + [Using property variables in CloudWatch dashboards to monitor multiple Lambda functions](example_iam_GettingStarted_032_section.md)
  + [Write custom activity data with a Lambda function after Amazon Cognito user authentication](example_cross_CognitoCustomActivityLog_section.md)
+ [Serverless examples](service_code_examples_serverless_examples.md)
  + [Connecting to an Amazon RDS database in a Lambda function](example_serverless_connect_RDS_Lambda_section.md)
  + [Invoke a Lambda function from a Kinesis trigger](example_serverless_Kinesis_Lambda_section.md)
  + [Invoke a Lambda function from a DynamoDB trigger](example_serverless_DynamoDB_Lambda_section.md)
  + [Invoke a Lambda function from a Amazon DocumentDB trigger](example_serverless_DocumentDB_Lambda_section.md)
  + [Invoke a Lambda function from an Amazon MSK trigger](example_serverless_MSK_Lambda_section.md)
  + [Invoke a Lambda function from an Amazon S3 trigger](example_serverless_S3_Lambda_section.md)
  + [Invoke a Lambda function from an Amazon SNS trigger](example_serverless_SNS_Lambda_section.md)
  + [Invoke a Lambda function from an Amazon SQS trigger](example_serverless_SQS_Lambda_section.md)
  + [Reporting batch item failures for Lambda functions with a Kinesis trigger](example_serverless_Kinesis_Lambda_batch_item_failures_section.md)
  + [Reporting batch item failures for Lambda functions with a DynamoDB trigger](example_serverless_DynamoDB_Lambda_batch_item_failures_section.md)
  + [Reporting batch item failures for Lambda functions with an Amazon SQS trigger](example_serverless_SQS_Lambda_batch_item_failures_section.md)
+ [AWS community contributions](service_code_examples_aws_community_contributions.md)
  + [Build and test a serverless application](example_tributary-lite_serverless-application_section.md)

# Basic examples for Lambda using AWS SDKs
<a name="service_code_examples_basics"></a>

The following code examples show how to use the basics of AWS Lambda with AWS SDKs. 

**Contents**
+ [Hello Lambda](example_lambda_Hello_section.md)
+ [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md)
+ [Actions](service_code_examples_actions.md)
  + [`CreateAlias`](example_lambda_CreateAlias_section.md)
  + [`CreateFunction`](example_lambda_CreateFunction_section.md)
  + [`DeleteAlias`](example_lambda_DeleteAlias_section.md)
  + [`DeleteFunction`](example_lambda_DeleteFunction_section.md)
  + [`DeleteFunctionConcurrency`](example_lambda_DeleteFunctionConcurrency_section.md)
  + [`DeleteProvisionedConcurrencyConfig`](example_lambda_DeleteProvisionedConcurrencyConfig_section.md)
  + [`GetAccountSettings`](example_lambda_GetAccountSettings_section.md)
  + [`GetAlias`](example_lambda_GetAlias_section.md)
  + [`GetFunction`](example_lambda_GetFunction_section.md)
  + [`GetFunctionConcurrency`](example_lambda_GetFunctionConcurrency_section.md)
  + [`GetFunctionConfiguration`](example_lambda_GetFunctionConfiguration_section.md)
  + [`GetPolicy`](example_lambda_GetPolicy_section.md)
  + [`GetProvisionedConcurrencyConfig`](example_lambda_GetProvisionedConcurrencyConfig_section.md)
  + [`Invoke`](example_lambda_Invoke_section.md)
  + [`ListFunctions`](example_lambda_ListFunctions_section.md)
  + [`ListProvisionedConcurrencyConfigs`](example_lambda_ListProvisionedConcurrencyConfigs_section.md)
  + [`ListTags`](example_lambda_ListTags_section.md)
  + [`ListVersionsByFunction`](example_lambda_ListVersionsByFunction_section.md)
  + [`PublishVersion`](example_lambda_PublishVersion_section.md)
  + [`PutFunctionConcurrency`](example_lambda_PutFunctionConcurrency_section.md)
  + [`PutProvisionedConcurrencyConfig`](example_lambda_PutProvisionedConcurrencyConfig_section.md)
  + [`RemovePermission`](example_lambda_RemovePermission_section.md)
  + [`TagResource`](example_lambda_TagResource_section.md)
  + [`UntagResource`](example_lambda_UntagResource_section.md)
  + [`UpdateAlias`](example_lambda_UpdateAlias_section.md)
  + [`UpdateFunctionCode`](example_lambda_UpdateFunctionCode_section.md)
  + [`UpdateFunctionConfiguration`](example_lambda_UpdateFunctionConfiguration_section.md)

# Hello Lambda
<a name="example_lambda_Hello_section"></a>

The following code examples show how to get started using Lambda.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
namespace LambdaActions;

using Amazon.Lambda;

public class HelloLambda
{
    static async Task Main(string[] args)
    {
        var lambdaClient = new AmazonLambdaClient();

        Console.WriteLine("Hello AWS Lambda");
        Console.WriteLine("Let's get started with AWS Lambda by listing your existing Lambda functions:");

        var response = await lambdaClient.ListFunctionsAsync();
        response.Functions.ForEach(function =>
        {
            Console.WriteLine($"{function.FunctionName}\t{function.Description}");
        });
    }
}
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda/hello_lambda#code-examples). 
Code for the CMakeLists.txt CMake file.  

```
# Set the minimum required version of CMake for this project.
cmake_minimum_required(VERSION 3.13)

# Set the AWS service components used by this project.
set(SERVICE_COMPONENTS lambda)

# Set this project's name.
project("hello_lambda")

# Set the C++ standard to use to build this target.
# At least C++ 11 is required for the AWS SDK for C++.
set(CMAKE_CXX_STANDARD 11)

# Use the MSVC variable to determine if this is a Windows build.
set(WINDOWS_BUILD ${MSVC})

if (WINDOWS_BUILD) # Set the location where CMake can find the installed libraries for the AWS SDK.
    string(REPLACE ";" "/aws-cpp-sdk-all;" SYSTEM_MODULE_PATH "${CMAKE_SYSTEM_PREFIX_PATH}/aws-cpp-sdk-all")
    list(APPEND CMAKE_PREFIX_PATH ${SYSTEM_MODULE_PATH})
endif ()

# Find the AWS SDK for C++ package.
find_package(AWSSDK REQUIRED COMPONENTS ${SERVICE_COMPONENTS})

if (WINDOWS_BUILD AND AWSSDK_INSTALL_AS_SHARED_LIBS)
     # Copy relevant AWS SDK for C++ libraries into the current binary directory for running and debugging.

     # set(BIN_SUB_DIR "/Debug") # if you are building from the command line you may need to uncomment this 
                                    # and set the proper subdirectory to the executables' location.

     AWSSDK_CPY_DYN_LIBS(SERVICE_COMPONENTS "" ${CMAKE_CURRENT_BINARY_DIR}${BIN_SUB_DIR})
endif ()

add_executable(${PROJECT_NAME}
        hello_lambda.cpp)

target_link_libraries(${PROJECT_NAME}
        ${AWSSDK_LINK_LIBRARIES})
```
Code for the hello\$1lambda.cpp source file.  

```
#include <aws/core/Aws.h>
#include <aws/lambda/LambdaClient.h>
#include <aws/lambda/model/ListFunctionsRequest.h>
#include <iostream>

/*
 *  A "Hello Lambda" starter application which initializes an AWS Lambda (Lambda) client and lists the Lambda functions.
 *
 *  main function
 *
 *  Usage: 'hello_lambda'
 *
 */

int main(int argc, char **argv) {
    Aws::SDKOptions options;
    // Optionally change the log level for debugging.
//   options.loggingOptions.logLevel = Utils::Logging::LogLevel::Debug;
    Aws::InitAPI(options); // Should only be called once.
    int result = 0;
    {
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region (overrides config file).
        // clientConfig.region = "us-east-1";

        Aws::Lambda::LambdaClient lambdaClient(clientConfig);
        std::vector<Aws::String> functions;
        Aws::String marker; // Used for pagination.

        do {
            Aws::Lambda::Model::ListFunctionsRequest request;
            if (!marker.empty()) {
                request.SetMarker(marker);
            }

            Aws::Lambda::Model::ListFunctionsOutcome outcome = lambdaClient.ListFunctions(
                    request);

            if (outcome.IsSuccess()) {
                const Aws::Lambda::Model::ListFunctionsResult &listFunctionsResult = outcome.GetResult();
                std::cout << listFunctionsResult.GetFunctions().size()
                          << " lambda functions were retrieved." << std::endl;

                for (const Aws::Lambda::Model::FunctionConfiguration &functionConfiguration: listFunctionsResult.GetFunctions()) {
                    functions.push_back(functionConfiguration.GetFunctionName());
                    std::cout << functions.size() << "  "
                              << functionConfiguration.GetDescription() << std::endl;
                    std::cout << "   "
                              << Aws::Lambda::Model::RuntimeMapper::GetNameForRuntime(
                                      functionConfiguration.GetRuntime()) << ": "
                              << functionConfiguration.GetHandler()
                              << std::endl;
                }
                marker = listFunctionsResult.GetNextMarker();
            } else {
                std::cerr << "Error with Lambda::ListFunctions. "
                          << outcome.GetError().GetMessage()
                          << std::endl;
                result = 1;
                break;
            }
        } while (!marker.empty());
    }


    Aws::ShutdownAPI(options); // Should only be called once.
    return result;
}
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/ListFunctions) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
package main

import (
	"context"
	"fmt"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
)

// main uses the AWS SDK for Go (v2) to create an AWS Lambda client and list up to 10
// functions in your account.
// This example uses the default settings specified in your shared credentials
// and config files.
func main() {
	ctx := context.Background()
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		fmt.Println("Couldn't load default configuration. Have you set up your AWS account?")
		fmt.Println(err)
		return
	}
	lambdaClient := lambda.NewFromConfig(sdkConfig)

	maxItems := 10
	fmt.Printf("Let's list up to %v functions for your account.\n", maxItems)
	result, err := lambdaClient.ListFunctions(ctx, &lambda.ListFunctionsInput{
		MaxItems: aws.Int32(int32(maxItems)),
	})
	if err != nil {
		fmt.Printf("Couldn't list functions for your account. Here's why: %v\n", err)
		return
	}
	if len(result.Functions) == 0 {
		fmt.Println("You don't have any functions!")
	} else {
		for _, function := range result.Functions {
			fmt.Printf("\t%v\n", *function.FunctionName)
		}
	}
}
```
+  For API details, see [ListFunctions](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.ListFunctions) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Lists the AWS Lambda functions associated with the current AWS account.
     *
     * @param awsLambda an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     *
     * @throws LambdaException if an error occurs while interacting with the AWS Lambda service
     */
    public static void listFunctions(LambdaClient awsLambda) {
        try {
            ListFunctionsResponse functionResult = awsLambda.listFunctions();
            List<FunctionConfiguration> list = functionResult.functions();
            for (FunctionConfiguration config : list) {
                System.out.println("The function name is " + config.functionName());
            }

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/ListFunctions) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
import { LambdaClient, paginateListFunctions } from "@aws-sdk/client-lambda";

const client = new LambdaClient({});

export const helloLambda = async () => {
  const paginator = paginateListFunctions({ client }, {});
  const functions = [];

  for await (const page of paginator) {
    const funcNames = page.Functions.map((f) => f.FunctionName);
    functions.push(...funcNames);
  }

  console.log("Functions:");
  console.log(functions.join("\n"));
  return functions;
};
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/ListFunctionsCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
import boto3


def main():
    """
    List the Lambda functions in your AWS account.
    """
    # Create the Lambda client
    lambda_client = boto3.client("lambda")

    # Use the paginator to list the functions
    paginator = lambda_client.get_paginator("list_functions")
    response_iterator = paginator.paginate()

    print("Here are the Lambda functions in your account:")
    for page in response_iterator:
        for function in page["Functions"]:
            print(f"  {function['FunctionName']}")


if __name__ == "__main__":
    main()
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
require 'aws-sdk-lambda'

# Creates an AWS Lambda client using the default credentials and configuration
def lambda_client
  Aws::Lambda::Client.new
end

# Lists the Lambda functions in your AWS account, paginating the results if necessary
def list_lambda_functions
  lambda = lambda_client

  # Use a pagination iterator to list all functions
  functions = []
  lambda.list_functions.each_page do |page|
    functions.concat(page.functions)
  end

  # Print the name and ARN of each function
  functions.each do |function|
    puts "Function name: #{function.function_name}"
    puts "Function ARN: #{function.function_arn}"
    puts
  end

  puts "Total functions: #{functions.count}"
end

list_lambda_functions if __FILE__ == $PROGRAM_NAME
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Ruby API Reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Learn the basics of Lambda with an AWS SDK
<a name="example_lambda_Scenario_GettingStartedFunctions_section"></a>

The following code examples show how to:
+ Create an IAM role and Lambda function, then upload handler code.
+ Invoke the function with a single parameter and get results.
+ Update the function code and configure with an environment variable.
+ Invoke the function with new parameters and get results. Display the returned execution log.
+ List the functions for your account, then clean up resources.

For more information, see [Create a Lambda function with the console](https://docs.aws.amazon.com/lambda/latest/dg/getting-started-create-function.html).

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 
Create methods that perform Lambda actions.  

```
namespace LambdaActions;

using Amazon.Lambda;
using Amazon.Lambda.Model;

/// <summary>
/// A class that implements AWS Lambda methods.
/// </summary>
public class LambdaWrapper
{
    private readonly IAmazonLambda _lambdaService;

    /// <summary>
    /// Constructor for the LambdaWrapper class.
    /// </summary>
    /// <param name="lambdaService">An initialized Lambda service client.</param>
    public LambdaWrapper(IAmazonLambda lambdaService)
    {
        _lambdaService = lambdaService;
    }

    /// <summary>
    /// Creates a new Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the function.</param>
    /// <param name="s3Bucket">The Amazon Simple Storage Service (Amazon S3)
    /// bucket where the zip file containing the code is located.</param>
    /// <param name="s3Key">The Amazon S3 key of the zip file.</param>
    /// <param name="role">The Amazon Resource Name (ARN) of a role with the
    /// appropriate Lambda permissions.</param>
    /// <param name="handler">The name of the handler function.</param>
    /// <returns>The Amazon Resource Name (ARN) of the newly created
    /// Lambda function.</returns>
    public async Task<string> CreateLambdaFunctionAsync(
        string functionName,
        string s3Bucket,
        string s3Key,
        string role,
        string handler)
    {
        // Defines the location for the function code.
        // S3Bucket - The S3 bucket where the file containing
        //            the source code is stored.
        // S3Key    - The name of the file containing the code.
        var functionCode = new FunctionCode
        {
            S3Bucket = s3Bucket,
            S3Key = s3Key,
        };

        var createFunctionRequest = new CreateFunctionRequest
        {
            FunctionName = functionName,
            Description = "Created by the Lambda .NET API",
            Code = functionCode,
            Handler = handler,
            Runtime = Runtime.Dotnet6,
            Role = role,
        };

        var reponse = await _lambdaService.CreateFunctionAsync(createFunctionRequest);
        return reponse.FunctionArn;
    }


    /// <summary>
    /// Delete an AWS Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to
    /// delete.</param>
    /// <returns>A Boolean value that indicates the success of the action.</returns>
    public async Task<bool> DeleteFunctionAsync(string functionName)
    {
        var request = new DeleteFunctionRequest
        {
            FunctionName = functionName,
        };

        var response = await _lambdaService.DeleteFunctionAsync(request);

        // A return value of NoContent means that the request was processed.
        // In this case, the function was deleted, and the return value
        // is intentionally blank.
        return response.HttpStatusCode == System.Net.HttpStatusCode.NoContent;
    }


    /// <summary>
    /// Gets information about a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function for
    /// which to retrieve information.</param>
    /// <returns>Async Task.</returns>
    public async Task<FunctionConfiguration> GetFunctionAsync(string functionName)
    {
        var functionRequest = new GetFunctionRequest
        {
            FunctionName = functionName,
        };

        var response = await _lambdaService.GetFunctionAsync(functionRequest);
        return response.Configuration;
    }


    /// <summary>
    /// Invoke a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to
    /// invoke.</param
    /// <param name="parameters">The parameter values that will be passed to the function.</param>
    /// <returns>A System Threading Task.</returns>
    public async Task<string> InvokeFunctionAsync(
        string functionName,
        string parameters)
    {
        var payload = parameters;
        var request = new InvokeRequest
        {
            FunctionName = functionName,
            Payload = payload,
        };

        var response = await _lambdaService.InvokeAsync(request);
        MemoryStream stream = response.Payload;
        string returnValue = System.Text.Encoding.UTF8.GetString(stream.ToArray());
        return returnValue;
    }


    /// <summary>
    /// Get a list of Lambda functions.
    /// </summary>
    /// <returns>A list of FunctionConfiguration objects.</returns>
    public async Task<List<FunctionConfiguration>> ListFunctionsAsync()
    {
        var functionList = new List<FunctionConfiguration>();

        var functionPaginator =
            _lambdaService.Paginators.ListFunctions(new ListFunctionsRequest());
        await foreach (var function in functionPaginator.Functions)
        {
            functionList.Add(function);
        }

        return functionList;
    }


    /// <summary>
    /// Update an existing Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to update.</param>
    /// <param name="bucketName">The bucket where the zip file containing
    /// the Lambda function code is stored.</param>
    /// <param name="key">The key name of the source code file.</param>
    /// <returns>Async Task.</returns>
    public async Task UpdateFunctionCodeAsync(
        string functionName,
        string bucketName,
        string key)
    {
        var functionCodeRequest = new UpdateFunctionCodeRequest
        {
            FunctionName = functionName,
            Publish = true,
            S3Bucket = bucketName,
            S3Key = key,
        };

        var response = await _lambdaService.UpdateFunctionCodeAsync(functionCodeRequest);
        Console.WriteLine($"The Function was last modified at {response.LastModified}.");
    }


    /// <summary>
    /// Update the code of a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the function to update.</param>
    /// <param name="functionHandler">The code that performs the function's actions.</param>
    /// <param name="environmentVariables">A dictionary of environment variables.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> UpdateFunctionConfigurationAsync(
        string functionName,
        string functionHandler,
        Dictionary<string, string> environmentVariables)
    {
        var request = new UpdateFunctionConfigurationRequest
        {
            Handler = functionHandler,
            FunctionName = functionName,
            Environment = new Amazon.Lambda.Model.Environment { Variables = environmentVariables },
        };

        var response = await _lambdaService.UpdateFunctionConfigurationAsync(request);

        Console.WriteLine(response.LastModified);

        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }


}
```
Create a function that runs the scenario.  

```
global using System.Threading.Tasks;
global using Amazon.IdentityManagement;
global using Amazon.Lambda;
global using LambdaActions;
global using LambdaScenarioCommon;
global using Microsoft.Extensions.DependencyInjection;
global using Microsoft.Extensions.Hosting;
global using Microsoft.Extensions.Logging;
global using Microsoft.Extensions.Logging.Console;
global using Microsoft.Extensions.Logging.Debug;


using Amazon.Lambda.Model;
using Microsoft.Extensions.Configuration;

namespace LambdaBasics;

public class LambdaBasics
{
    private static ILogger logger = null!;

    static async Task Main(string[] args)
    {
        // Set up dependency injection for the Amazon service.
        using var host = Host.CreateDefaultBuilder(args)
            .ConfigureLogging(logging =>
                logging.AddFilter("System", LogLevel.Debug)
                    .AddFilter<DebugLoggerProvider>("Microsoft", LogLevel.Information)
                    .AddFilter<ConsoleLoggerProvider>("Microsoft", LogLevel.Trace))
            .ConfigureServices((_, services) =>
            services.AddAWSService<IAmazonLambda>()
            .AddAWSService<IAmazonIdentityManagementService>()
            .AddTransient<LambdaWrapper>()
            .AddTransient<LambdaRoleWrapper>()
            .AddTransient<UIWrapper>()
        )
        .Build();

        var configuration = new ConfigurationBuilder()
            .SetBasePath(Directory.GetCurrentDirectory())
            .AddJsonFile("settings.json") // Load test settings from .json file.
            .AddJsonFile("settings.local.json",
            true) // Optionally load local settings.
        .Build();


        logger = LoggerFactory.Create(builder => { builder.AddConsole(); })
            .CreateLogger<LambdaBasics>();

        var lambdaWrapper = host.Services.GetRequiredService<LambdaWrapper>();
        var lambdaRoleWrapper = host.Services.GetRequiredService<LambdaRoleWrapper>();
        var uiWrapper = host.Services.GetRequiredService<UIWrapper>();

        string functionName = configuration["FunctionName"]!;
        string roleName = configuration["RoleName"]!;
        string policyDocument = "{" +
            " \"Version\": \"2012-10-17\"," +
            " \"Statement\": [ " +
            "    {" +
            "        \"Effect\": \"Allow\"," +
            "        \"Principal\": {" +
            "            \"Service\": \"lambda.amazonaws.com\" " +
            "    }," +
            "        \"Action\": \"sts:AssumeRole\" " +
            "    }" +
            "]" +
        "}";

        var incrementHandler = configuration["IncrementHandler"];
        var calculatorHandler = configuration["CalculatorHandler"];
        var bucketName = configuration["BucketName"];
        var incrementKey = configuration["IncrementKey"];
        var calculatorKey = configuration["CalculatorKey"];
        var policyArn = configuration["PolicyArn"];

        uiWrapper.DisplayLambdaBasicsOverview();

        // Create the policy to use with the AWS Lambda functions and then attach the
        // policy to a new role.
        var roleArn = await lambdaRoleWrapper.CreateLambdaRoleAsync(roleName, policyDocument);

        Console.WriteLine("Waiting for role to become active.");
        uiWrapper.WaitABit(15, "Wait until the role is active before trying to use it.");

        // Attach the appropriate AWS Identity and Access Management (IAM) role policy to the new role.
        var success = await lambdaRoleWrapper.AttachLambdaRolePolicyAsync(policyArn, roleName);
        uiWrapper.WaitABit(10, "Allow time for the IAM policy to be attached to the role.");

        // Create the Lambda function using a zip file stored in an Amazon Simple Storage Service
        // (Amazon S3) bucket.
        uiWrapper.DisplayTitle("Create Lambda Function");
        Console.WriteLine($"Creating the AWS Lambda function: {functionName}.");
        var lambdaArn = await lambdaWrapper.CreateLambdaFunctionAsync(
            functionName,
            bucketName,
            incrementKey,
            roleArn,
            incrementHandler);

        Console.WriteLine("Waiting for the new function to be available.");
        Console.WriteLine($"The AWS Lambda ARN is {lambdaArn}");

        // Get the Lambda function.
        Console.WriteLine($"Getting the {functionName} AWS Lambda function.");
        FunctionConfiguration config;
        do
        {
            config = await lambdaWrapper.GetFunctionAsync(functionName);
            Console.Write(".");
        }
        while (config.State != State.Active);

        Console.WriteLine($"\nThe function, {functionName} has been created.");
        Console.WriteLine($"The runtime of this Lambda function is {config.Runtime}.");

        uiWrapper.PressEnter();

        // List the Lambda functions.
        uiWrapper.DisplayTitle("Listing all Lambda functions.");
        var functions = await lambdaWrapper.ListFunctionsAsync();
        DisplayFunctionList(functions);

        uiWrapper.DisplayTitle("Invoke increment function");
        Console.WriteLine("Now that it has been created, invoke the Lambda increment function.");
        string? value;
        do
        {
            Console.Write("Enter a value to increment: ");
            value = Console.ReadLine();
        }
        while (string.IsNullOrEmpty(value));

        string functionParameters = "{" +
            "\"action\": \"increment\", " +
            "\"x\": \"" + value + "\"" +
        "}";
        var answer = await lambdaWrapper.InvokeFunctionAsync(functionName, functionParameters);
        Console.WriteLine($"{value} + 1 = {answer}.");

        uiWrapper.DisplayTitle("Update function");
        Console.WriteLine("Now update the Lambda function code.");
        await lambdaWrapper.UpdateFunctionCodeAsync(functionName, bucketName, calculatorKey);

        do
        {
            config = await lambdaWrapper.GetFunctionAsync(functionName);
            Console.Write(".");
        }
        while (config.LastUpdateStatus == LastUpdateStatus.InProgress);

        await lambdaWrapper.UpdateFunctionConfigurationAsync(
            functionName,
            calculatorHandler,
            new Dictionary<string, string> { { "LOG_LEVEL", "DEBUG" } });

        do
        {
            config = await lambdaWrapper.GetFunctionAsync(functionName);
            Console.Write(".");
        }
        while (config.LastUpdateStatus == LastUpdateStatus.InProgress);

        uiWrapper.DisplayTitle("Call updated function");
        Console.WriteLine("Now call the updated function...");

        bool done = false;

        do
        {
            string? opSelected;

            Console.WriteLine("Select the operation to perform:");
            Console.WriteLine("\t1. add");
            Console.WriteLine("\t2. subtract");
            Console.WriteLine("\t3. multiply");
            Console.WriteLine("\t4. divide");
            Console.WriteLine("\tOr enter \"q\" to quit.");
            Console.WriteLine("Enter the number (1, 2, 3, 4, or q) of the operation you want to perform: ");
            do
            {
                Console.Write("Your choice? ");
                opSelected = Console.ReadLine();
            }
            while (opSelected == string.Empty);

            var operation = (opSelected) switch
            {
                "1" => "add",
                "2" => "subtract",
                "3" => "multiply",
                "4" => "divide",
                "q" => "quit",
                _ => "add",
            };

            if (operation == "quit")
            {
                done = true;
            }
            else
            {
                // Get two numbers and an action from the user.
                value = string.Empty;
                do
                {
                    Console.Write("Enter the first value: ");
                    value = Console.ReadLine();
                }
                while (value == string.Empty);

                string? value2;
                do
                {
                    Console.Write("Enter a second value: ");
                    value2 = Console.ReadLine();
                }
                while (value2 == string.Empty);

                functionParameters = "{" +
                    "\"action\": \"" + operation + "\", " +
                    "\"x\": \"" + value + "\"," +
                    "\"y\": \"" + value2 + "\"" +
                "}";

                answer = await lambdaWrapper.InvokeFunctionAsync(functionName, functionParameters);
                Console.WriteLine($"The answer when we {operation} the two numbers is: {answer}.");
            }

            uiWrapper.PressEnter();
        } while (!done);

        // Delete the function created earlier.

        uiWrapper.DisplayTitle("Clean up resources");
        // Detach the IAM policy from the IAM role.
        Console.WriteLine("First detach the IAM policy from the role.");
        success = await lambdaRoleWrapper.DetachLambdaRolePolicyAsync(policyArn, roleName);
        uiWrapper.WaitABit(15, "Let's wait for the policy to be fully detached from the role.");

        Console.WriteLine("Delete the AWS Lambda function.");
        success = await lambdaWrapper.DeleteFunctionAsync(functionName);
        if (success)
        {
            Console.WriteLine($"The {functionName} function was deleted.");
        }
        else
        {
            Console.WriteLine($"Could not remove the function {functionName}");
        }

        // Now delete the IAM role created for use with the functions
        // created by the application.
        Console.WriteLine("Now we can delete the role that we created.");
        success = await lambdaRoleWrapper.DeleteLambdaRoleAsync(roleName);
        if (success)
        {
            Console.WriteLine("The role has been successfully removed.");
        }
        else
        {
            Console.WriteLine("Couldn't delete the role.");
        }

        Console.WriteLine("The Lambda Scenario is now complete.");
        uiWrapper.PressEnter();

        // Displays a formatted list of existing functions returned by the
        // LambdaMethods.ListFunctions.
        void DisplayFunctionList(List<FunctionConfiguration> functions)
        {
            functions.ForEach(functionConfig =>
            {
                Console.WriteLine($"{functionConfig.FunctionName}\t{functionConfig.Description}");
            });
        }
    }
}


namespace LambdaActions;

using Amazon.IdentityManagement;
using Amazon.IdentityManagement.Model;

public class LambdaRoleWrapper
{
    private readonly IAmazonIdentityManagementService _lambdaRoleService;

    public LambdaRoleWrapper(IAmazonIdentityManagementService lambdaRoleService)
    {
        _lambdaRoleService = lambdaRoleService;
    }

    /// <summary>
    /// Attach an AWS Identity and Access Management (IAM) role policy to the
    /// IAM role to be assumed by the AWS Lambda functions created for the scenario.
    /// </summary>
    /// <param name="policyArn">The Amazon Resource Name (ARN) of the IAM policy.</param>
    /// <param name="roleName">The name of the IAM role to attach the IAM policy to.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> AttachLambdaRolePolicyAsync(string policyArn, string roleName)
    {
        var response = await _lambdaRoleService.AttachRolePolicyAsync(new AttachRolePolicyRequest { PolicyArn = policyArn, RoleName = roleName });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }

    /// <summary>
    /// Create a new IAM role.
    /// </summary>
    /// <param name="roleName">The name of the IAM role to create.</param>
    /// <param name="policyDocument">The policy document for the new IAM role.</param>
    /// <returns>A string representing the ARN for newly created role.</returns>
    public async Task<string> CreateLambdaRoleAsync(string roleName, string policyDocument)
    {
        var request = new CreateRoleRequest
        {
            AssumeRolePolicyDocument = policyDocument,
            RoleName = roleName,
        };

        var response = await _lambdaRoleService.CreateRoleAsync(request);
        return response.Role.Arn;
    }

    /// <summary>
    /// Deletes an IAM role.
    /// </summary>
    /// <param name="roleName">The name of the role to delete.</param>
    /// <returns>A Boolean value indicating the success of the operation.</returns>
    public async Task<bool> DeleteLambdaRoleAsync(string roleName)
    {
        var request = new DeleteRoleRequest
        {
            RoleName = roleName,
        };

        var response = await _lambdaRoleService.DeleteRoleAsync(request);
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }

    public async Task<bool> DetachLambdaRolePolicyAsync(string policyArn, string roleName)
    {
        var response = await _lambdaRoleService.DetachRolePolicyAsync(new DetachRolePolicyRequest { PolicyArn = policyArn, RoleName = roleName });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }
}


namespace LambdaScenarioCommon;

public class UIWrapper
{
    public readonly string SepBar = new('-', Console.WindowWidth);

    /// <summary>
    /// Show information about the AWS Lambda Basics scenario.
    /// </summary>
    public void DisplayLambdaBasicsOverview()
    {
        Console.Clear();

        DisplayTitle("Welcome to AWS Lambda Basics");
        Console.WriteLine("This example application does the following:");
        Console.WriteLine("\t1. Creates an AWS Identity and Access Management (IAM) role that will be assumed by the functions we create.");
        Console.WriteLine("\t2. Attaches an IAM role policy that has Lambda permissions.");
        Console.WriteLine("\t3. Creates a Lambda function that increments the value passed to it.");
        Console.WriteLine("\t4. Calls the increment function and passes a value.");
        Console.WriteLine("\t5. Updates the code so that the function is a simple calculator.");
        Console.WriteLine("\t6. Calls the calculator function with the values entered.");
        Console.WriteLine("\t7. Deletes the Lambda function.");
        Console.WriteLine("\t7. Detaches the IAM role policy.");
        Console.WriteLine("\t8. Deletes the IAM role.");
        PressEnter();
    }

    /// <summary>
    /// Display a message and wait until the user presses enter.
    /// </summary>
    public void PressEnter()
    {
        Console.Write("\nPress <Enter> to continue. ");
        _ = Console.ReadLine();
        Console.WriteLine();
    }

    /// <summary>
    /// Pad a string with spaces to center it on the console display.
    /// </summary>
    /// <param name="strToCenter">The string to be centered.</param>
    /// <returns>The padded string.</returns>
    public string CenterString(string strToCenter)
    {
        var padAmount = (Console.WindowWidth - strToCenter.Length) / 2;
        var leftPad = new string(' ', padAmount);
        return $"{leftPad}{strToCenter}";
    }

    /// <summary>
    /// Display a line of hyphens, the centered text of the title and another
    /// line of hyphens.
    /// </summary>
    /// <param name="strTitle">The string to be displayed.</param>
    public void DisplayTitle(string strTitle)
    {
        Console.WriteLine(SepBar);
        Console.WriteLine(CenterString(strTitle));
        Console.WriteLine(SepBar);
    }

    /// <summary>
    /// Display a countdown and wait for a number of seconds.
    /// </summary>
    /// <param name="numSeconds">The number of seconds to wait.</param>
    public void WaitABit(int numSeconds, string msg)
    {
        Console.WriteLine(msg);

        // Wait for the requested number of seconds.
        for (int i = numSeconds; i > 0; i--)
        {
            System.Threading.Thread.Sleep(1000);
            Console.Write($"{i}...");
        }

        PressEnter();
    }
}
```
Define a Lambda handler that increments a number.  

```
using Amazon.Lambda.Core;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace LambdaIncrement;

public class Function
{

    /// <summary>
    /// A simple function increments the integer parameter.
    /// </summary>
    /// <param name="input">A JSON string containing an action, which must be
    /// "increment" and a string representing the value to increment.</param>
    /// <param name="context">The context object passed by Lambda containing
    /// information about invocation, function, and execution environment.</param>
    /// <returns>A string representing the incremented value of the parameter.</returns>
    public int FunctionHandler(Dictionary<string, string> input, ILambdaContext context)
    {
        if (input["action"] == "increment")
        {
            int inputValue = Convert.ToInt32(input["x"]);
            return inputValue + 1;
        }
        else
        {
            return 0;
        }
    }
}
```
Define a second Lambda handler that performs arithmetic operations.  

```
using Amazon.Lambda.Core;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace LambdaCalculator;

public class Function
{

    /// <summary>
    /// A simple function that takes two number in string format and performs
    /// the requested arithmetic function.
    /// </summary>
    /// <param name="input">JSON data containing an action, and x and y values.
    /// Valid actions include: add, subtract, multiply, and divide.</param>
    /// <param name="context">The context object passed by Lambda containing
    /// information about invocation, function, and execution environment.</param>
    /// <returns>A string representing the results of the calculation.</returns>
    public int FunctionHandler(Dictionary<string, string> input, ILambdaContext context)
    {
        var action = input["action"];
        int x = Convert.ToInt32(input["x"]);
        int y = Convert.ToInt32(input["y"]);
        int result;
        switch (action)
        {
            case "add":
                result = x + y;
                break;
            case "subtract":
                result = x - y;
                break;
            case "multiply":
                result = x * y;
                break;
            case "divide":
                if (y == 0)
                {
                    Console.Error.WriteLine("Divide by zero error.");
                    result = 0;
                }
                else
                    result = x / y;
                break;
            default:
                Console.Error.WriteLine($"{action} is not a valid operation.");
                result = 0;
                break;
        }
        return result;
    }
}
```
+ For API details, see the following topics in *AWS SDK for .NET API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
//! Get started with functions scenario.
/*!
 \param clientConfig: AWS client configuration.
 \return bool: Successful completion.
 */
bool AwsDoc::Lambda::getStartedWithFunctionsScenario(
        const Aws::Client::ClientConfiguration &clientConfig) {

    Aws::Lambda::LambdaClient client(clientConfig);

    // 1. Create an AWS Identity and Access Management (IAM) role for Lambda function.
    Aws::String roleArn;
    if (!getIamRoleArn(roleArn, clientConfig)) {
        return false;
    }

    // 2. Create a Lambda function.
    int seconds = 0;
    do {
        Aws::Lambda::Model::CreateFunctionRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetDescription(LAMBDA_DESCRIPTION); // Optional.
#if USE_CPP_LAMBDA_FUNCTION
        request.SetRuntime(Aws::Lambda::Model::Runtime::provided_al2);
        request.SetTimeout(15);
        request.SetMemorySize(128);

        // Assume the AWS Lambda function was built in Docker with same architecture
        // as this code.
#if  defined(__x86_64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::x86_64});
#elif defined(__aarch64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::arm64});
#else
#error "Unimplemented architecture"
#endif // defined(architecture)
#else
        request.SetRuntime(Aws::Lambda::Model::Runtime::python3_9);
#endif
        request.SetRole(roleArn);
        request.SetHandler(LAMBDA_HANDLER_NAME);
        request.SetPublish(true);
        Aws::Lambda::Model::FunctionCode code;
        std::ifstream ifstream(INCREMENT_LAMBDA_CODE.c_str(),
                               std::ios_base::in | std::ios_base::binary);
        if (!ifstream.is_open()) {
            std::cerr << "Error opening file " << INCREMENT_LAMBDA_CODE << "." << std::endl;

#if USE_CPP_LAMBDA_FUNCTION
            std::cerr
                    << "The cpp Lambda function must be built following the instructions in the cpp_lambda/README.md file. "
                    << std::endl;
#endif
            deleteIamRole(clientConfig);
            return false;
        }

        Aws::StringStream buffer;
        buffer << ifstream.rdbuf();

        code.SetZipFile(Aws::Utils::ByteBuffer((unsigned char *) buffer.str().c_str(),
                                               buffer.str().length()));
        request.SetCode(code);

        Aws::Lambda::Model::CreateFunctionOutcome outcome = client.CreateFunction(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda function was successfully created. " << seconds
                      << " seconds elapsed." << std::endl;
            break;
        }
        else if (outcome.GetError().GetErrorType() ==
                 Aws::Lambda::LambdaErrors::INVALID_PARAMETER_VALUE &&
                 outcome.GetError().GetMessage().find("role") >= 0) {
            if ((seconds % 5) == 0) { // Log status every 10 seconds.
                std::cout
                        << "Waiting for the IAM role to become available as a CreateFunction parameter. "
                        << seconds
                        << " seconds elapsed." << std::endl;

                std::cout << outcome.GetError().GetMessage() << std::endl;
            }
        }
        else {
            std::cerr << "Error with CreateFunction. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            deleteIamRole(clientConfig);
            return false;
        }
        ++seconds;
        std::this_thread::sleep_for(std::chrono::seconds(1));
    } while (60 > seconds);

    std::cout << "The current Lambda function increments 1 by an input." << std::endl;

    // 3.  Invoke the Lambda function.
    {
        int increment = askQuestionForInt("Enter an increment integer: ");

        Aws::Lambda::Model::InvokeResult invokeResult;
        Aws::Utils::Json::JsonValue jsonPayload;
        jsonPayload.WithString("action", "increment");
        jsonPayload.WithInteger("number", increment);
        if (invokeLambdaFunction(jsonPayload, Aws::Lambda::Model::LogType::Tail,
                                 invokeResult, client)) {
            Aws::Utils::Json::JsonValue jsonValue(invokeResult.GetPayload());
            Aws::Map<Aws::String, Aws::Utils::Json::JsonView> values =
                    jsonValue.View().GetAllObjects();
            auto iter = values.find("result");
            if (iter != values.end() && iter->second.IsIntegerType()) {
                {
                    std::cout << INCREMENT_RESUlT_PREFIX
                              << iter->second.AsInteger() << std::endl;
                }
            }
            else {
                std::cout << "There was an error in execution. Here is the log."
                          << std::endl;
                Aws::Utils::ByteBuffer buffer = Aws::Utils::HashingUtils::Base64Decode(
                        invokeResult.GetLogResult());
                std::cout << "With log " << buffer.GetUnderlyingData() << std::endl;
            }
        }
    }

    std::cout
            << "The Lambda function will now be updated with new code. Press return to continue, ";
    Aws::String answer;
    std::getline(std::cin, answer);

    // 4.  Update the Lambda function code.
    {
        Aws::Lambda::Model::UpdateFunctionCodeRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        std::ifstream ifstream(CALCULATOR_LAMBDA_CODE.c_str(),
                               std::ios_base::in | std::ios_base::binary);
        if (!ifstream.is_open()) {
            std::cerr << "Error opening file " << INCREMENT_LAMBDA_CODE << "." << std::endl;

#if USE_CPP_LAMBDA_FUNCTION
            std::cerr
                    << "The cpp Lambda function must be built following the instructions in the cpp_lambda/README.md file. "
                    << std::endl;
#endif
            deleteLambdaFunction(client);
            deleteIamRole(clientConfig);
            return false;
        }

        Aws::StringStream buffer;
        buffer << ifstream.rdbuf();
        request.SetZipFile(
                Aws::Utils::ByteBuffer((unsigned char *) buffer.str().c_str(),
                                       buffer.str().length()));
        request.SetPublish(true);

        Aws::Lambda::Model::UpdateFunctionCodeOutcome outcome = client.UpdateFunctionCode(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda code was successfully updated." << std::endl;
        }
        else {
            std::cerr << "Error with Lambda::UpdateFunctionCode. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    }

    std::cout
            << "This function uses an environment variable to control the logging level."
            << std::endl;
    std::cout
            << "UpdateFunctionConfiguration will be used to set the LOG_LEVEL to DEBUG."
            << std::endl;
    seconds = 0;

    // 5.  Update the Lambda function configuration.
    do {
        ++seconds;
        std::this_thread::sleep_for(std::chrono::seconds(1));
        Aws::Lambda::Model::UpdateFunctionConfigurationRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        Aws::Lambda::Model::Environment environment;
        environment.AddVariables("LOG_LEVEL", "DEBUG");
        request.SetEnvironment(environment);

        Aws::Lambda::Model::UpdateFunctionConfigurationOutcome outcome = client.UpdateFunctionConfiguration(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda configuration was successfully updated."
                      << std::endl;
            break;
        }

            // RESOURCE_IN_USE: function code update not completed.
        else if (outcome.GetError().GetErrorType() !=
                 Aws::Lambda::LambdaErrors::RESOURCE_IN_USE) {
            if ((seconds % 10) == 0) { // Log status every 10 seconds.
                std::cout << "Lambda function update in progress . After " << seconds
                          << " seconds elapsed." << std::endl;
            }
        }
        else {
            std::cerr << "Error with Lambda::UpdateFunctionConfiguration. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }

    } while (0 < seconds);

    if (0 > seconds) {
        std::cerr << "Function failed to become active." << std::endl;
    }
    else {
        std::cout << "Updated function active after " << seconds << " seconds."
                  << std::endl;
    }

    std::cout
            << "\nThe new code applies an arithmetic operator to two variables, x an y."
            << std::endl;
    std::vector<Aws::String> operators = {"plus", "minus", "times", "divided-by"};
    for (size_t i = 0; i < operators.size(); ++i) {
        std::cout << "   " << i + 1 << " " << operators[i] << std::endl;
    }

    // 6.  Invoke the updated Lambda function.
    do {
        int operatorIndex = askQuestionForIntRange("Select an operator index 1 - 4 ", 1,
                                                   4);
        int x = askQuestionForInt("Enter an integer for the x value ");
        int y = askQuestionForInt("Enter an integer for the y value ");

        Aws::Utils::Json::JsonValue calculateJsonPayload;
        calculateJsonPayload.WithString("action", operators[operatorIndex - 1]);
        calculateJsonPayload.WithInteger("x", x);
        calculateJsonPayload.WithInteger("y", y);
        Aws::Lambda::Model::InvokeResult calculatedResult;
        if (invokeLambdaFunction(calculateJsonPayload,
                                 Aws::Lambda::Model::LogType::Tail,
                                 calculatedResult, client)) {
            Aws::Utils::Json::JsonValue jsonValue(calculatedResult.GetPayload());
            Aws::Map<Aws::String, Aws::Utils::Json::JsonView> values =
                    jsonValue.View().GetAllObjects();
            auto iter = values.find("result");
            if (iter != values.end() && iter->second.IsIntegerType()) {
                std::cout << ARITHMETIC_RESUlT_PREFIX << x << " "
                          << operators[operatorIndex - 1] << " "
                          << y << " is " << iter->second.AsInteger() << std::endl;
            }
            else if (iter != values.end() && iter->second.IsFloatingPointType()) {
                std::cout << ARITHMETIC_RESUlT_PREFIX << x << " "
                          << operators[operatorIndex - 1] << " "
                          << y << " is " << iter->second.AsDouble() << std::endl;
            }
            else {
                std::cout << "There was an error in execution. Here is the log."
                          << std::endl;
                Aws::Utils::ByteBuffer buffer = Aws::Utils::HashingUtils::Base64Decode(
                        calculatedResult.GetLogResult());
                std::cout << "With log " << buffer.GetUnderlyingData() << std::endl;
            }
        }

        answer = askQuestion("Would you like to try another operation? (y/n) ");
    } while (answer == "y");

    std::cout
            << "A list of the lambda functions will be retrieved. Press return to continue, ";
    std::getline(std::cin, answer);

    // 7.  List the Lambda functions.

    std::vector<Aws::String> functions;
    Aws::String marker;

    do {
        Aws::Lambda::Model::ListFunctionsRequest request;
        if (!marker.empty()) {
            request.SetMarker(marker);
        }

        Aws::Lambda::Model::ListFunctionsOutcome outcome = client.ListFunctions(
                request);

        if (outcome.IsSuccess()) {
            const Aws::Lambda::Model::ListFunctionsResult &result = outcome.GetResult();
            std::cout << result.GetFunctions().size()
                      << " lambda functions were retrieved." << std::endl;

            for (const Aws::Lambda::Model::FunctionConfiguration &functionConfiguration: result.GetFunctions()) {
                functions.push_back(functionConfiguration.GetFunctionName());
                std::cout << functions.size() << "  "
                          << functionConfiguration.GetDescription() << std::endl;
                std::cout << "   "
                          << Aws::Lambda::Model::RuntimeMapper::GetNameForRuntime(
                                  functionConfiguration.GetRuntime()) << ": "
                          << functionConfiguration.GetHandler()
                          << std::endl;
            }
            marker = result.GetNextMarker();
        }
        else {
            std::cerr << "Error with Lambda::ListFunctions. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    } while (!marker.empty());

    // 8.  Get a Lambda function.
    if (!functions.empty()) {
        std::stringstream question;
        question << "Choose a function to retrieve between 1 and " << functions.size()
                 << " ";
        int functionIndex = askQuestionForIntRange(question.str(), 1,
                                                   static_cast<int>(functions.size()));

        Aws::String functionName = functions[functionIndex - 1];

        Aws::Lambda::Model::GetFunctionRequest request;
        request.SetFunctionName(functionName);

        Aws::Lambda::Model::GetFunctionOutcome outcome = client.GetFunction(request);

        if (outcome.IsSuccess()) {
            std::cout << "Function retrieve.\n" <<
                      outcome.GetResult().GetConfiguration().Jsonize().View().WriteReadable()
                      << std::endl;
        }
        else {
            std::cerr << "Error with Lambda::GetFunction. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    }

    std::cout << "The resources will be deleted. Press return to continue, ";
    std::getline(std::cin, answer);

    // 9.  Delete the Lambda function.
    bool result = deleteLambdaFunction(client);

    // 10. Delete the IAM role.
    return result && deleteIamRole(clientConfig);
}

//! Routine which invokes a Lambda function and returns the result.
/*!
 \param jsonPayload: Payload for invoke function.
 \param logType: Log type setting for invoke function.
 \param invokeResult: InvokeResult object to receive the result.
 \param client: Lambda client.
 \return bool: Successful completion.
 */
bool
AwsDoc::Lambda::invokeLambdaFunction(const Aws::Utils::Json::JsonValue &jsonPayload,
                                     Aws::Lambda::Model::LogType logType,
                                     Aws::Lambda::Model::InvokeResult &invokeResult,
                                     const Aws::Lambda::LambdaClient &client) {
    int seconds = 0;
    bool result = false;
    /*
     * In this example, the Invoke function can be called before recently created resources are
     * available.  The Invoke function is called repeatedly until the resources are
     * available.
     */
    do {
        Aws::Lambda::Model::InvokeRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetLogType(logType);
        std::shared_ptr<Aws::IOStream> payload = Aws::MakeShared<Aws::StringStream>(
                "FunctionTest");
        *payload << jsonPayload.View().WriteReadable();
        request.SetBody(payload);
        request.SetContentType("application/json");
        Aws::Lambda::Model::InvokeOutcome outcome = client.Invoke(request);

        if (outcome.IsSuccess()) {
            invokeResult = std::move(outcome.GetResult());
            result = true;
            break;
        }

            // ACCESS_DENIED: because the role is not available yet.
            // RESOURCE_CONFLICT: because the Lambda function is being created or updated.
        else if ((outcome.GetError().GetErrorType() ==
                  Aws::Lambda::LambdaErrors::ACCESS_DENIED) ||
                 (outcome.GetError().GetErrorType() ==
                  Aws::Lambda::LambdaErrors::RESOURCE_CONFLICT)) {
            if ((seconds % 5) == 0) { // Log status every 10 seconds.
                std::cout << "Waiting for the invoke api to be available, status " <<
                          ((outcome.GetError().GetErrorType() ==
                            Aws::Lambda::LambdaErrors::ACCESS_DENIED ?
                            "ACCESS_DENIED" : "RESOURCE_CONFLICT")) << ". " << seconds
                          << " seconds elapsed." << std::endl;
            }
        }
        else {
            std::cerr << "Error with Lambda::InvokeRequest. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            break;
        }
        ++seconds;
        std::this_thread::sleep_for(std::chrono::seconds(1));
    } while (seconds < 60);

    return result;
}
```
+ For API details, see the following topics in *AWS SDK for C\$1\$1 API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 
Create an interactive scenario that shows you how to get started with Lambda functions.  

```
import (
	"archive/zip"
	"bytes"
	"context"
	"encoding/base64"
	"encoding/json"
	"errors"
	"fmt"
	"log"
	"os"
	"strings"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/iam"
	iamtypes "github.com/aws/aws-sdk-go-v2/service/iam/types"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/lambda/actions"
)

// GetStartedFunctionsScenario shows you how to use AWS Lambda to perform the following
// actions:
//
//  1. Create an AWS Identity and Access Management (IAM) role and Lambda function, then upload handler code.
//  2. Invoke the function with a single parameter and get results.
//  3. Update the function code and configure with an environment variable.
//  4. Invoke the function with new parameters and get results. Display the returned execution log.
//  5. List the functions for your account, then clean up resources.
type GetStartedFunctionsScenario struct {
	sdkConfig       aws.Config
	functionWrapper actions.FunctionWrapper
	questioner      demotools.IQuestioner
	helper          IScenarioHelper
	isTestRun       bool
}

// NewGetStartedFunctionsScenario constructs a GetStartedFunctionsScenario instance from a configuration.
// It uses the specified config to get a Lambda client and create wrappers for the actions
// used in the scenario.
func NewGetStartedFunctionsScenario(sdkConfig aws.Config, questioner demotools.IQuestioner,
	helper IScenarioHelper) GetStartedFunctionsScenario {
	lambdaClient := lambda.NewFromConfig(sdkConfig)
	return GetStartedFunctionsScenario{
		sdkConfig:       sdkConfig,
		functionWrapper: actions.FunctionWrapper{LambdaClient: lambdaClient},
		questioner:      questioner,
		helper:          helper,
	}
}

// Run runs the interactive scenario.
func (scenario GetStartedFunctionsScenario) Run(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("Something went wrong with the demo.\n")
		}
	}()

	log.Println(strings.Repeat("-", 88))
	log.Println("Welcome to the AWS Lambda get started with functions demo.")
	log.Println(strings.Repeat("-", 88))

	role := scenario.GetOrCreateRole(ctx)
	funcName := scenario.CreateFunction(ctx, role)
	scenario.InvokeIncrement(ctx, funcName)
	scenario.UpdateFunction(ctx, funcName)
	scenario.InvokeCalculator(ctx, funcName)
	scenario.ListFunctions(ctx)
	scenario.Cleanup(ctx, role, funcName)

	log.Println(strings.Repeat("-", 88))
	log.Println("Thanks for watching!")
	log.Println(strings.Repeat("-", 88))
}

// GetOrCreateRole checks whether the specified role exists and returns it if it does.
// Otherwise, a role is created that specifies Lambda as a trusted principal.
// The AWSLambdaBasicExecutionRole managed policy is attached to the role and the role
// is returned.
func (scenario GetStartedFunctionsScenario) GetOrCreateRole(ctx context.Context) *iamtypes.Role {
	var role *iamtypes.Role
	iamClient := iam.NewFromConfig(scenario.sdkConfig)
	log.Println("First, we need an IAM role that Lambda can assume.")
	roleName := scenario.questioner.Ask("Enter a name for the role:", demotools.NotEmpty{})
	getOutput, err := iamClient.GetRole(ctx, &iam.GetRoleInput{
		RoleName: aws.String(roleName)})
	if err != nil {
		var noSuch *iamtypes.NoSuchEntityException
		if errors.As(err, &noSuch) {
			log.Printf("Role %v doesn't exist. Creating it....\n", roleName)
		} else {
			log.Panicf("Couldn't check whether role %v exists. Here's why: %v\n",
				roleName, err)
		}
	} else {
		role = getOutput.Role
		log.Printf("Found role %v.\n", *role.RoleName)
	}
	if role == nil {
		trustPolicy := PolicyDocument{
			Version: "2012-10-17",
			Statement: []PolicyStatement{{
				Effect:    "Allow",
				Principal: map[string]string{"Service": "lambda.amazonaws.com"},
				Action:    []string{"sts:AssumeRole"},
			}},
		}
		policyArn := "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
		createOutput, err := iamClient.CreateRole(ctx, &iam.CreateRoleInput{
			AssumeRolePolicyDocument: aws.String(trustPolicy.String()),
			RoleName:                 aws.String(roleName),
		})
		if err != nil {
			log.Panicf("Couldn't create role %v. Here's why: %v\n", roleName, err)
		}
		role = createOutput.Role
		_, err = iamClient.AttachRolePolicy(ctx, &iam.AttachRolePolicyInput{
			PolicyArn: aws.String(policyArn),
			RoleName:  aws.String(roleName),
		})
		if err != nil {
			log.Panicf("Couldn't attach a policy to role %v. Here's why: %v\n", roleName, err)
		}
		log.Printf("Created role %v.\n", *role.RoleName)
		log.Println("Let's give AWS a few seconds to propagate resources...")
		scenario.helper.Pause(10)
	}
	log.Println(strings.Repeat("-", 88))
	return role
}

// CreateFunction creates a Lambda function and uploads a handler written in Python.
// The code for the Python handler is packaged as a []byte in .zip format.
func (scenario GetStartedFunctionsScenario) CreateFunction(ctx context.Context, role *iamtypes.Role) string {
	log.Println("Let's create a function that increments a number.\n" +
		"The function uses the 'lambda_handler_basic.py' script found in the \n" +
		"'handlers' directory of this project.")
	funcName := scenario.questioner.Ask("Enter a name for the Lambda function:", demotools.NotEmpty{})
	zipPackage := scenario.helper.CreateDeploymentPackage("lambda_handler_basic.py", fmt.Sprintf("%v.py", funcName))
	log.Printf("Creating function %v and waiting for it to be ready.", funcName)
	funcState := scenario.functionWrapper.CreateFunction(ctx, funcName, fmt.Sprintf("%v.lambda_handler", funcName),
		role.Arn, zipPackage)
	log.Printf("Your function is %v.", funcState)
	log.Println(strings.Repeat("-", 88))
	return funcName
}

// InvokeIncrement invokes a Lambda function that increments a number. The function
// parameters are contained in a Go struct that is used to serialize the parameters to
// a JSON payload that is passed to the function.
// The result payload is deserialized into a Go struct that contains an int value.
func (scenario GetStartedFunctionsScenario) InvokeIncrement(ctx context.Context, funcName string) {
	parameters := actions.IncrementParameters{Action: "increment"}
	log.Println("Let's invoke our function. This function increments a number.")
	parameters.Number = scenario.questioner.AskInt("Enter a number to increment:", demotools.NotEmpty{})
	log.Printf("Invoking %v with %v...\n", funcName, parameters.Number)
	invokeOutput := scenario.functionWrapper.Invoke(ctx, funcName, parameters, false)
	var payload actions.LambdaResultInt
	err := json.Unmarshal(invokeOutput.Payload, &payload)
	if err != nil {
		log.Panicf("Couldn't unmarshal payload from invoking %v. Here's why: %v\n",
			funcName, err)
	}
	log.Printf("Invoking %v with %v returned %v.\n", funcName, parameters.Number, payload)
	log.Println(strings.Repeat("-", 88))
}

// UpdateFunction updates the code for a Lambda function by uploading a simple arithmetic
// calculator written in Python. The code for the Python handler is packaged as a
// []byte in .zip format.
// After the code is updated, the configuration is also updated with a new log
// level that instructs the handler to log additional information.
func (scenario GetStartedFunctionsScenario) UpdateFunction(ctx context.Context, funcName string) {
	log.Println("Let's update the function to an arithmetic calculator.\n" +
		"The function uses the 'lambda_handler_calculator.py' script found in the \n" +
		"'handlers' directory of this project.")
	scenario.questioner.Ask("Press Enter when you're ready.")
	log.Println("Creating deployment package...")
	zipPackage := scenario.helper.CreateDeploymentPackage("lambda_handler_calculator.py",
		fmt.Sprintf("%v.py", funcName))
	log.Println("...and updating the Lambda function and waiting for it to be ready.")
	funcState := scenario.functionWrapper.UpdateFunctionCode(ctx, funcName, zipPackage)
	log.Printf("Updated function %v. Its current state is %v.", funcName, funcState)
	log.Println("This function uses an environment variable to control logging level.")
	log.Println("Let's set it to DEBUG to get the most logging.")
	scenario.functionWrapper.UpdateFunctionConfiguration(ctx, funcName,
		map[string]string{"LOG_LEVEL": "DEBUG"})
	log.Println(strings.Repeat("-", 88))
}

// InvokeCalculator invokes the Lambda calculator function. The parameters are stored in a
// Go struct that is used to serialize the parameters to a JSON payload. That payload is then passed
// to the function.
// The result payload is deserialized to a Go struct that stores the result as either an
// int or float32, depending on the kind of operation that was specified.
func (scenario GetStartedFunctionsScenario) InvokeCalculator(ctx context.Context, funcName string) {
	wantInvoke := true
	choices := []string{"plus", "minus", "times", "divided-by"}
	for wantInvoke {
		choice := scenario.questioner.AskChoice("Select an arithmetic operation:\n", choices)
		x := scenario.questioner.AskInt("Enter a value for x:", demotools.NotEmpty{})
		y := scenario.questioner.AskInt("Enter a value for y:", demotools.NotEmpty{})
		log.Printf("Invoking %v %v %v...", x, choices[choice], y)
		calcParameters := actions.CalculatorParameters{
			Action: choices[choice],
			X:      x,
			Y:      y,
		}
		invokeOutput := scenario.functionWrapper.Invoke(ctx, funcName, calcParameters, true)
		var payload any
		if choice == 3 { // divide-by results in a float.
			payload = actions.LambdaResultFloat{}
		} else {
			payload = actions.LambdaResultInt{}
		}
		err := json.Unmarshal(invokeOutput.Payload, &payload)
		if err != nil {
			log.Panicf("Couldn't unmarshal payload from invoking %v. Here's why: %v\n",
				funcName, err)
		}
		log.Printf("Invoking %v with %v %v %v returned %v.\n", funcName,
			calcParameters.X, calcParameters.Action, calcParameters.Y, payload)
		scenario.questioner.Ask("Press Enter to see the logs from the call.")
		logRes, err := base64.StdEncoding.DecodeString(*invokeOutput.LogResult)
		if err != nil {
			log.Panicf("Couldn't decode log result. Here's why: %v\n", err)
		}
		log.Println(string(logRes))
		wantInvoke = scenario.questioner.AskBool("Do you want to calculate again? (y/n)", "y")
	}
	log.Println(strings.Repeat("-", 88))
}

// ListFunctions lists up to the specified number of functions for your account.
func (scenario GetStartedFunctionsScenario) ListFunctions(ctx context.Context) {
	count := scenario.questioner.AskInt(
		"Let's list functions for your account. How many do you want to see?", demotools.NotEmpty{})
	functions := scenario.functionWrapper.ListFunctions(ctx, count)
	log.Printf("Found %v functions:", len(functions))
	for _, function := range functions {
		log.Printf("\t%v", *function.FunctionName)
	}
	log.Println(strings.Repeat("-", 88))
}

// Cleanup removes the IAM and Lambda resources created by the example.
func (scenario GetStartedFunctionsScenario) Cleanup(ctx context.Context, role *iamtypes.Role, funcName string) {
	if scenario.questioner.AskBool("Do you want to clean up resources created for this example? (y/n)",
		"y") {
		iamClient := iam.NewFromConfig(scenario.sdkConfig)
		policiesOutput, err := iamClient.ListAttachedRolePolicies(ctx,
			&iam.ListAttachedRolePoliciesInput{RoleName: role.RoleName})
		if err != nil {
			log.Panicf("Couldn't get policies attached to role %v. Here's why: %v\n",
				*role.RoleName, err)
		}
		for _, policy := range policiesOutput.AttachedPolicies {
			_, err = iamClient.DetachRolePolicy(ctx, &iam.DetachRolePolicyInput{
				PolicyArn: policy.PolicyArn, RoleName: role.RoleName,
			})
			if err != nil {
				log.Panicf("Couldn't detach policy %v from role %v. Here's why: %v\n",
					*policy.PolicyArn, *role.RoleName, err)
			}
		}
		_, err = iamClient.DeleteRole(ctx, &iam.DeleteRoleInput{RoleName: role.RoleName})
		if err != nil {
			log.Panicf("Couldn't delete role %v. Here's why: %v\n", *role.RoleName, err)
		}
		log.Printf("Deleted role %v.\n", *role.RoleName)

		scenario.functionWrapper.DeleteFunction(ctx, funcName)
		log.Printf("Deleted function %v.\n", funcName)
	} else {
		log.Println("Okay. Don't forget to delete the resources when you're done with them.")
	}
}

// IScenarioHelper abstracts I/O and wait functions from a scenario so that they
// can be mocked for unit testing.
type IScenarioHelper interface {
	Pause(secs int)
	CreateDeploymentPackage(sourceFile string, destinationFile string) *bytes.Buffer
}

// ScenarioHelper lets the caller specify the path to Lambda handler functions.
type ScenarioHelper struct {
	HandlerPath string
}

// Pause waits for the specified number of seconds.
func (helper *ScenarioHelper) Pause(secs int) {
	time.Sleep(time.Duration(secs) * time.Second)
}

// CreateDeploymentPackage creates an AWS Lambda deployment package from a source file. The
// deployment package is stored in .zip format in a bytes.Buffer. The buffer can be
// used to pass a []byte to Lambda when creating the function.
// The specified destinationFile is the name to give the file when it's deployed to Lambda.
func (helper *ScenarioHelper) CreateDeploymentPackage(sourceFile string, destinationFile string) *bytes.Buffer {
	var err error
	buffer := &bytes.Buffer{}
	writer := zip.NewWriter(buffer)
	zFile, err := writer.Create(destinationFile)
	if err != nil {
		log.Panicf("Couldn't create destination archive %v. Here's why: %v\n", destinationFile, err)
	}
	sourceBody, err := os.ReadFile(fmt.Sprintf("%v/%v", helper.HandlerPath, sourceFile))
	if err != nil {
		log.Panicf("Couldn't read handler source file %v. Here's why: %v\n",
			sourceFile, err)
	} else {
		_, err = zFile.Write(sourceBody)
		if err != nil {
			log.Panicf("Couldn't write handler %v to zip archive. Here's why: %v\n",
				sourceFile, err)
		}
	}
	err = writer.Close()
	if err != nil {
		log.Panicf("Couldn't close zip writer. Here's why: %v\n", err)
	}
	return buffer
}
```
Create a struct that wraps individual Lambda actions.  

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}


// GetFunction gets data about the Lambda function specified by functionName.
func (wrapper FunctionWrapper) GetFunction(ctx context.Context, functionName string) types.State {
	var state types.State
	funcOutput, err := wrapper.LambdaClient.GetFunction(ctx, &lambda.GetFunctionInput{
		FunctionName: aws.String(functionName),
	})
	if err != nil {
		log.Panicf("Couldn't get function %v. Here's why: %v\n", functionName, err)
	} else {
		state = funcOutput.Configuration.State
	}
	return state
}



// CreateFunction creates a new Lambda function from code contained in the zipPackage
// buffer. The specified handlerName must match the name of the file and function
// contained in the uploaded code. The role specified by iamRoleArn is assumed by
// Lambda and grants specific permissions.
// When the function already exists, types.StateActive is returned.
// When the function is created, a lambda.FunctionActiveV2Waiter is used to wait until the
// function is active.
func (wrapper FunctionWrapper) CreateFunction(ctx context.Context, functionName string, handlerName string,
	iamRoleArn *string, zipPackage *bytes.Buffer) types.State {
	var state types.State
	_, err := wrapper.LambdaClient.CreateFunction(ctx, &lambda.CreateFunctionInput{
		Code:         &types.FunctionCode{ZipFile: zipPackage.Bytes()},
		FunctionName: aws.String(functionName),
		Role:         iamRoleArn,
		Handler:      aws.String(handlerName),
		Publish:      true,
		Runtime:      types.RuntimePython39,
	})
	if err != nil {
		var resConflict *types.ResourceConflictException
		if errors.As(err, &resConflict) {
			log.Printf("Function %v already exists.\n", functionName)
			state = types.StateActive
		} else {
			log.Panicf("Couldn't create function %v. Here's why: %v\n", functionName, err)
		}
	} else {
		waiter := lambda.NewFunctionActiveV2Waiter(wrapper.LambdaClient)
		funcOutput, err := waiter.WaitForOutput(ctx, &lambda.GetFunctionInput{
			FunctionName: aws.String(functionName)}, 1*time.Minute)
		if err != nil {
			log.Panicf("Couldn't wait for function %v to be active. Here's why: %v\n", functionName, err)
		} else {
			state = funcOutput.Configuration.State
		}
	}
	return state
}



// UpdateFunctionCode updates the code for the Lambda function specified by functionName.
// The existing code for the Lambda function is entirely replaced by the code in the
// zipPackage buffer. After the update action is called, a lambda.FunctionUpdatedV2Waiter
// is used to wait until the update is successful.
func (wrapper FunctionWrapper) UpdateFunctionCode(ctx context.Context, functionName string, zipPackage *bytes.Buffer) types.State {
	var state types.State
	_, err := wrapper.LambdaClient.UpdateFunctionCode(ctx, &lambda.UpdateFunctionCodeInput{
		FunctionName: aws.String(functionName), ZipFile: zipPackage.Bytes(),
	})
	if err != nil {
		log.Panicf("Couldn't update code for function %v. Here's why: %v\n", functionName, err)
	} else {
		waiter := lambda.NewFunctionUpdatedV2Waiter(wrapper.LambdaClient)
		funcOutput, err := waiter.WaitForOutput(ctx, &lambda.GetFunctionInput{
			FunctionName: aws.String(functionName)}, 1*time.Minute)
		if err != nil {
			log.Panicf("Couldn't wait for function %v to be active. Here's why: %v\n", functionName, err)
		} else {
			state = funcOutput.Configuration.State
		}
	}
	return state
}



// UpdateFunctionConfiguration updates a map of environment variables configured for
// the Lambda function specified by functionName.
func (wrapper FunctionWrapper) UpdateFunctionConfiguration(ctx context.Context, functionName string, envVars map[string]string) {
	_, err := wrapper.LambdaClient.UpdateFunctionConfiguration(ctx, &lambda.UpdateFunctionConfigurationInput{
		FunctionName: aws.String(functionName),
		Environment:  &types.Environment{Variables: envVars},
	})
	if err != nil {
		log.Panicf("Couldn't update configuration for %v. Here's why: %v", functionName, err)
	}
}



// ListFunctions lists up to maxItems functions for the account. This function uses a
// lambda.ListFunctionsPaginator to paginate the results.
func (wrapper FunctionWrapper) ListFunctions(ctx context.Context, maxItems int) []types.FunctionConfiguration {
	var functions []types.FunctionConfiguration
	paginator := lambda.NewListFunctionsPaginator(wrapper.LambdaClient, &lambda.ListFunctionsInput{
		MaxItems: aws.Int32(int32(maxItems)),
	})
	for paginator.HasMorePages() && len(functions) < maxItems {
		pageOutput, err := paginator.NextPage(ctx)
		if err != nil {
			log.Panicf("Couldn't list functions for your account. Here's why: %v\n", err)
		}
		functions = append(functions, pageOutput.Functions...)
	}
	return functions
}



// DeleteFunction deletes the Lambda function specified by functionName.
func (wrapper FunctionWrapper) DeleteFunction(ctx context.Context, functionName string) {
	_, err := wrapper.LambdaClient.DeleteFunction(ctx, &lambda.DeleteFunctionInput{
		FunctionName: aws.String(functionName),
	})
	if err != nil {
		log.Panicf("Couldn't delete function %v. Here's why: %v\n", functionName, err)
	}
}



// Invoke invokes the Lambda function specified by functionName, passing the parameters
// as a JSON payload. When getLog is true, types.LogTypeTail is specified, which tells
// Lambda to include the last few log lines in the returned result.
func (wrapper FunctionWrapper) Invoke(ctx context.Context, functionName string, parameters any, getLog bool) *lambda.InvokeOutput {
	logType := types.LogTypeNone
	if getLog {
		logType = types.LogTypeTail
	}
	payload, err := json.Marshal(parameters)
	if err != nil {
		log.Panicf("Couldn't marshal parameters to JSON. Here's why %v\n", err)
	}
	invokeOutput, err := wrapper.LambdaClient.Invoke(ctx, &lambda.InvokeInput{
		FunctionName: aws.String(functionName),
		LogType:      logType,
		Payload:      payload,
	})
	if err != nil {
		log.Panicf("Couldn't invoke function %v. Here's why: %v\n", functionName, err)
	}
	return invokeOutput
}



// IncrementParameters is used to serialize parameters to the increment Lambda handler.
type IncrementParameters struct {
	Action string `json:"action"`
	Number int    `json:"number"`
}

// CalculatorParameters is used to serialize parameters to the calculator Lambda handler.
type CalculatorParameters struct {
	Action string `json:"action"`
	X      int    `json:"x"`
	Y      int    `json:"y"`
}

// LambdaResultInt is used to deserialize an int result from a Lambda handler.
type LambdaResultInt struct {
	Result int `json:"result"`
}

// LambdaResultFloat is used to deserialize a float32 result from a Lambda handler.
type LambdaResultFloat struct {
	Result float32 `json:"result"`
}
```
Define a Lambda handler that increments a number.  

```
import logging

logger = logging.getLogger()
logger.setLevel(logging.INFO)


def lambda_handler(event, context):
    """
    Accepts an action and a single number, performs the specified action on the number,
    and returns the result. The only allowable action is 'increment'.

    :param event: The event dict that contains the parameters sent when the function
                  is invoked.
    :param context: The context in which the function is called.
    :return: The result of the action.
    """
    result = None
    action = event.get("action")
    if action == "increment":
        result = event.get("number", 0) + 1
        logger.info("Calculated result of %s", result)
    else:
        logger.error("%s is not a valid action.", action)

    response = {"result": result}
    return response
```
Define a second Lambda handler that performs arithmetic operations.  

```
import logging
import os


logger = logging.getLogger()

# Define a list of Python lambda functions that are called by this AWS Lambda function.
ACTIONS = {
    "plus": lambda x, y: x + y,
    "minus": lambda x, y: x - y,
    "times": lambda x, y: x * y,
    "divided-by": lambda x, y: x / y,
}


def lambda_handler(event, context):
    """
    Accepts an action and two numbers, performs the specified action on the numbers,
    and returns the result.

    :param event: The event dict that contains the parameters sent when the function
                  is invoked.
    :param context: The context in which the function is called.
    :return: The result of the specified action.
    """
    # Set the log level based on a variable configured in the Lambda environment.
    logger.setLevel(os.environ.get("LOG_LEVEL", logging.INFO))
    logger.debug("Event: %s", event)

    action = event.get("action")
    func = ACTIONS.get(action)
    x = event.get("x")
    y = event.get("y")
    result = None
    try:
        if func is not None and x is not None and y is not None:
            result = func(x, y)
            logger.info("%s %s %s is %s", x, action, y, result)
        else:
            logger.error("I can't calculate %s %s %s.", x, action, y)
    except ZeroDivisionError:
        logger.warning("I can't divide %s by 0!", x)

    response = {"result": result}
    return response
```
+ For API details, see the following topics in *AWS SDK for Go API Reference*.
  + [CreateFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.CreateFunction)
  + [DeleteFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.DeleteFunction)
  + [GetFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.GetFunction)
  + [Invoke](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.Invoke)
  + [ListFunctions](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.ListFunctions)
  + [UpdateFunctionCode](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.UpdateFunctionConfiguration)

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
/*
 *  Lambda function names appear as:
 *
 *  arn:aws:lambda:us-west-2:335556666777:function:HelloFunction
 *
 *  To find this value, look at the function in the AWS Management Console.
 *
 *  Before running this Java code example, set up your development environment, including your credentials.
 *
 *  For more information, see this documentation topic:
 *
 *  https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 *
 *  This example performs the following tasks:
 *
 * 1. Creates an AWS Lambda function.
 * 2. Gets a specific AWS Lambda function.
 * 3. Lists all Lambda functions.
 * 4. Invokes a Lambda function.
 * 5. Updates the Lambda function code and invokes it again.
 * 6. Updates a Lambda function's configuration value.
 * 7. Deletes a Lambda function.
 */

public class LambdaScenario {
    public static final String DASHES = new String(new char[80]).replace("\0", "-");

    public static void main(String[] args) throws InterruptedException {
        final String usage = """

            Usage:
                <functionName> <role> <handler> <bucketName> <key>\s

            Where:
                functionName - The name of the Lambda function.\s
                role - The AWS Identity and Access Management (IAM) service role that has Lambda permissions.\s
                handler - The fully qualified method name (for example, example.Handler::handleRequest).\s
                bucketName - The Amazon Simple Storage Service (Amazon S3) bucket name that contains the .zip or .jar used to update the Lambda function's code.\s
                key - The Amazon S3 key name that represents the .zip or .jar (for example, LambdaHello-1.0-SNAPSHOT.jar).
                """;

        if (args.length != 5) {
              System.out.println(usage);
              return;
        }

        String functionName = args[0];
        String role = args[1];
        String handler = args[2];
        String bucketName = args[3];
        String key = args[4];
        LambdaClient awsLambda = LambdaClient.builder()
            .build();

        System.out.println(DASHES);
        System.out.println("Welcome to the AWS Lambda Basics scenario.");
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("1. Create an AWS Lambda function.");
        String funArn = createLambdaFunction(awsLambda, functionName, key, bucketName, role, handler);
        System.out.println("The AWS Lambda ARN is " + funArn);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("2. Get the " + functionName + " AWS Lambda function.");
        getFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("3. List all AWS Lambda functions.");
        listFunctions(awsLambda);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("4. Invoke the Lambda function.");
        System.out.println("*** Sleep for 1 min to get Lambda function ready.");
        Thread.sleep(60000);
        invokeFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("5. Update the Lambda function code and invoke it again.");
        updateFunctionCode(awsLambda, functionName, bucketName, key);
        System.out.println("*** Sleep for 1 min to get Lambda function ready.");
        Thread.sleep(60000);
        invokeFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("6. Update a Lambda function's configuration value.");
        updateFunctionConfiguration(awsLambda, functionName, handler);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("7. Delete the AWS Lambda function.");
        LambdaScenario.deleteLambdaFunction(awsLambda, functionName);
        System.out.println(DASHES);

        System.out.println(DASHES);
        System.out.println("The AWS Lambda scenario completed successfully");
        System.out.println(DASHES);
        awsLambda.close();
    }

    /**
     * Creates a new Lambda function in AWS using the AWS Lambda Java API.
     *
     * @param awsLambda    the AWS Lambda client used to interact with the AWS Lambda service
     * @param functionName the name of the Lambda function to create
     * @param key          the S3 key of the function code
     * @param bucketName   the name of the S3 bucket containing the function code
     * @param role         the IAM role to assign to the Lambda function
     * @param handler      the fully qualified class name of the function handler
     * @return the Amazon Resource Name (ARN) of the created Lambda function
     */
    public static String createLambdaFunction(LambdaClient awsLambda,
                                              String functionName,
                                              String key,
                                              String bucketName,
                                              String role,
                                              String handler) {

        try {
            LambdaWaiter waiter = awsLambda.waiter();
            FunctionCode code = FunctionCode.builder()
                .s3Key(key)
                .s3Bucket(bucketName)
                .build();

            CreateFunctionRequest functionRequest = CreateFunctionRequest.builder()
                .functionName(functionName)
                .description("Created by the Lambda Java API")
                .code(code)
                .handler(handler)
                .runtime(Runtime.JAVA17)
                .role(role)
                .build();

            // Create a Lambda function using a waiter
            CreateFunctionResponse functionResponse = awsLambda.createFunction(functionRequest);
            GetFunctionRequest getFunctionRequest = GetFunctionRequest.builder()
                .functionName(functionName)
                .build();
            WaiterResponse<GetFunctionResponse> waiterResponse = waiter.waitUntilFunctionExists(getFunctionRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            return functionResponse.functionArn();

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
        return "";
    }

    /**
     * Retrieves information about an AWS Lambda function.
     *
     * @param awsLambda    an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     * @param functionName the name of the AWS Lambda function to retrieve information about
     */
    public static void getFunction(LambdaClient awsLambda, String functionName) {
        try {
            GetFunctionRequest functionRequest = GetFunctionRequest.builder()
                .functionName(functionName)
                .build();

            GetFunctionResponse response = awsLambda.getFunction(functionRequest);
            System.out.println("The runtime of this Lambda function is " + response.configuration().runtime());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    /**
     * Lists the AWS Lambda functions associated with the current AWS account.
     *
     * @param awsLambda an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     *
     * @throws LambdaException if an error occurs while interacting with the AWS Lambda service
     */
    public static void listFunctions(LambdaClient awsLambda) {
        try {
            ListFunctionsResponse functionResult = awsLambda.listFunctions();
            List<FunctionConfiguration> list = functionResult.functions();
            for (FunctionConfiguration config : list) {
                System.out.println("The function name is " + config.functionName());
            }

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    /**
     * Invokes a specific AWS Lambda function.
     *
     * @param awsLambda    an instance of {@link LambdaClient} to interact with the AWS Lambda service
     * @param functionName the name of the AWS Lambda function to be invoked
     */
    public static void invokeFunction(LambdaClient awsLambda, String functionName) {
        InvokeResponse res;
        try {
            // Need a SdkBytes instance for the payload.
            JSONObject jsonObj = new JSONObject();
            jsonObj.put("inputValue", "2000");
            String json = jsonObj.toString();
            SdkBytes payload = SdkBytes.fromUtf8String(json);

            InvokeRequest request = InvokeRequest.builder()
                .functionName(functionName)
                .payload(payload)
                .build();

            res = awsLambda.invoke(request);
            String value = res.payload().asUtf8String();
            System.out.println(value);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    /**
     * Updates the code for an AWS Lambda function.
     *
     * @param awsLambda  the AWS Lambda client
     * @param functionName the name of the Lambda function to update
     * @param bucketName the name of the S3 bucket where the function code is located
     * @param key the key (file name) of the function code in the S3 bucket
     * @throws LambdaException if there is an error updating the function code
     */
    public static void updateFunctionCode(LambdaClient awsLambda, String functionName, String bucketName, String key) {
        try {
            LambdaWaiter waiter = awsLambda.waiter();
            UpdateFunctionCodeRequest functionCodeRequest = UpdateFunctionCodeRequest.builder()
                .functionName(functionName)
                .publish(true)
                .s3Bucket(bucketName)
                .s3Key(key)
                .build();

            UpdateFunctionCodeResponse response = awsLambda.updateFunctionCode(functionCodeRequest);
            GetFunctionConfigurationRequest getFunctionConfigRequest = GetFunctionConfigurationRequest.builder()
                .functionName(functionName)
                .build();

            WaiterResponse<GetFunctionConfigurationResponse> waiterResponse = waiter
                .waitUntilFunctionUpdated(getFunctionConfigRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            System.out.println("The last modified value is " + response.lastModified());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    /**
     * Updates the configuration of an AWS Lambda function.
     *
     * @param awsLambda     the {@link LambdaClient} instance to use for the AWS Lambda operation
     * @param functionName  the name of the AWS Lambda function to update
     * @param handler       the new handler for the AWS Lambda function
     *
     * @throws LambdaException if there is an error while updating the function configuration
     */
    public static void updateFunctionConfiguration(LambdaClient awsLambda, String functionName, String handler) {
        try {
            UpdateFunctionConfigurationRequest configurationRequest = UpdateFunctionConfigurationRequest.builder()
                .functionName(functionName)
                .handler(handler)
                .runtime(Runtime.JAVA17)
                .build();

            awsLambda.updateFunctionConfiguration(configurationRequest);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }

    /**
     * Deletes an AWS Lambda function.
     *
     * @param awsLambda     an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     * @param functionName  the name of the Lambda function to be deleted
     *
     * @throws LambdaException if an error occurs while deleting the Lambda function
     */
    public static void deleteLambdaFunction(LambdaClient awsLambda, String functionName) {
        try {
            DeleteFunctionRequest request = DeleteFunctionRequest.builder()
                .functionName(functionName)
                .build();

            awsLambda.deleteFunction(request);
            System.out.println("The " + functionName + " function was deleted");

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}
```
+ For API details, see the following topics in *AWS SDK for Java 2.x API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda/scenarios/basic#code-examples). 
Create an AWS Identity and Access Management (IAM) role that grants Lambda permission to write to logs.  

```
    logger.log(`Creating role (${NAME_ROLE_LAMBDA})...`);
    const response = await createRole(NAME_ROLE_LAMBDA);

import { AttachRolePolicyCommand, IAMClient } from "@aws-sdk/client-iam";

const client = new IAMClient({});

/**
 *
 * @param {string} policyArn
 * @param {string} roleName
 */
export const attachRolePolicy = (policyArn, roleName) => {
  const command = new AttachRolePolicyCommand({
    PolicyArn: policyArn,
    RoleName: roleName,
  });

  return client.send(command);
};
```
Create a Lambda function and upload handler code.  

```
const createFunction = async (funcName, roleArn) => {
  const client = new LambdaClient({});
  const code = await readFile(`${dirname}../functions/${funcName}.zip`);

  const command = new CreateFunctionCommand({
    Code: { ZipFile: code },
    FunctionName: funcName,
    Role: roleArn,
    Architectures: [Architecture.arm64],
    Handler: "index.handler", // Required when sending a .zip file
    PackageType: PackageType.Zip, // Required when sending a .zip file
    Runtime: Runtime.nodejs16x, // Required when sending a .zip file
  });

  return client.send(command);
};
```
Invoke the function with a single parameter and get results.  

```
const invoke = async (funcName, payload) => {
  const client = new LambdaClient({});
  const command = new InvokeCommand({
    FunctionName: funcName,
    Payload: JSON.stringify(payload),
    LogType: LogType.Tail,
  });

  const { Payload, LogResult } = await client.send(command);
  const result = Buffer.from(Payload).toString();
  const logs = Buffer.from(LogResult, "base64").toString();
  return { logs, result };
};
```
Update the function code and configure its Lambda environment with an environment variable.  

```
const updateFunctionCode = async (funcName, newFunc) => {
  const client = new LambdaClient({});
  const code = await readFile(`${dirname}../functions/${newFunc}.zip`);
  const command = new UpdateFunctionCodeCommand({
    ZipFile: code,
    FunctionName: funcName,
    Architectures: [Architecture.arm64],
    Handler: "index.handler", // Required when sending a .zip file
    PackageType: PackageType.Zip, // Required when sending a .zip file
    Runtime: Runtime.nodejs16x, // Required when sending a .zip file
  });

  return client.send(command);
};

const updateFunctionConfiguration = (funcName) => {
  const client = new LambdaClient({});
  const config = readFileSync(`${dirname}../functions/config.json`).toString();
  const command = new UpdateFunctionConfigurationCommand({
    ...JSON.parse(config),
    FunctionName: funcName,
  });
  const result = client.send(command);
  waitForFunctionUpdated({ FunctionName: funcName });
  return result;
};
```
List the functions for your account.  

```
const listFunctions = () => {
  const client = new LambdaClient({});
  const command = new ListFunctionsCommand({});

  return client.send(command);
};
```
Delete the IAM role and the Lambda function.  

```
import { DeleteRoleCommand, IAMClient } from "@aws-sdk/client-iam";

const client = new IAMClient({});

/**
 *
 * @param {string} roleName
 */
export const deleteRole = (roleName) => {
  const command = new DeleteRoleCommand({ RoleName: roleName });
  return client.send(command);
};

/**
 * @param {string} funcName
 */
const deleteFunction = (funcName) => {
  const client = new LambdaClient({});
  const command = new DeleteFunctionCommand({ FunctionName: funcName });
  return client.send(command);
};
```
+ For API details, see the following topics in *AWS SDK for JavaScript API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/CreateFunctionCommand)
  + [DeleteFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/DeleteFunctionCommand)
  + [GetFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/GetFunctionCommand)
  + [Invoke](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/InvokeCommand)
  + [ListFunctions](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/ListFunctionsCommand)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/UpdateFunctionCodeCommand)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/UpdateFunctionConfigurationCommand)

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/lambda#code-examples). 

```
suspend fun main(args: Array<String>) {
    val usage = """
        Usage:
            <functionName> <role> <handler> <bucketName> <updatedBucketName> <key> 

        Where:
            functionName - The name of the AWS Lambda function. 
            role - The AWS Identity and Access Management (IAM) service role that has AWS Lambda permissions. 
            handler - The fully qualified method name (for example, example.Handler::handleRequest). 
            bucketName - The Amazon Simple Storage Service (Amazon S3) bucket name that contains the ZIP or JAR used for the Lambda function's code.
            updatedBucketName - The Amazon S3 bucket name that contains the .zip or .jar used to update the Lambda function's code. 
            key - The Amazon S3 key name that represents the .zip or .jar file (for example, LambdaHello-1.0-SNAPSHOT.jar).
            """

    if (args.size != 6) {
        println(usage)
        exitProcess(1)
    }

    val functionName = args[0]
    val role = args[1]
    val handler = args[2]
    val bucketName = args[3]
    val updatedBucketName = args[4]
    val key = args[5]

    println("Creating a Lambda function named $functionName.")
    val funArn = createScFunction(functionName, bucketName, key, handler, role)
    println("The AWS Lambda ARN is $funArn")

    // Get a specific Lambda function.
    println("Getting the $functionName AWS Lambda function.")
    getFunction(functionName)

    // List the Lambda functions.
    println("Listing all AWS Lambda functions.")
    listFunctionsSc()

    // Invoke the Lambda function.
    println("*** Invoke the Lambda function.")
    invokeFunctionSc(functionName)

    // Update the AWS Lambda function code.
    println("*** Update the Lambda function code.")
    updateFunctionCode(functionName, updatedBucketName, key)

    // println("*** Invoke the function again after updating the code.")
    invokeFunctionSc(functionName)

    // Update the AWS Lambda function configuration.
    println("Update the run time of the function.")
    updateFunctionConfiguration(functionName, handler)

    // Delete the AWS Lambda function.
    println("Delete the AWS Lambda function.")
    delFunction(functionName)
}

suspend fun createScFunction(
    myFunctionName: String,
    s3BucketName: String,
    myS3Key: String,
    myHandler: String,
    myRole: String,
): String {
    val functionCode =
        FunctionCode {
            s3Bucket = s3BucketName
            s3Key = myS3Key
        }

    val request =
        CreateFunctionRequest {
            functionName = myFunctionName
            code = functionCode
            description = "Created by the Lambda Kotlin API"
            handler = myHandler
            role = myRole
            runtime = Runtime.Java17
        }

    // Create a Lambda function using a waiter
    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val functionResponse = awsLambda.createFunction(request)
        awsLambda.waitUntilFunctionActive {
            functionName = myFunctionName
        }
        return functionResponse.functionArn.toString()
    }
}

suspend fun getFunction(functionNameVal: String) {
    val functionRequest =
        GetFunctionRequest {
            functionName = functionNameVal
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val response = awsLambda.getFunction(functionRequest)
        println("The runtime of this Lambda function is ${response.configuration?.runtime}")
    }
}

suspend fun listFunctionsSc() {
    val request =
        ListFunctionsRequest {
            maxItems = 10
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val response = awsLambda.listFunctions(request)
        response.functions?.forEach { function ->
            println("The function name is ${function.functionName}")
        }
    }
}

suspend fun invokeFunctionSc(functionNameVal: String) {
    val json = """{"inputValue":"1000"}"""
    val byteArray = json.trimIndent().encodeToByteArray()
    val request =
        InvokeRequest {
            functionName = functionNameVal
            payload = byteArray
            logType = LogType.Tail
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val res = awsLambda.invoke(request)
        println("The function payload is ${res.payload?.toString(Charsets.UTF_8)}")
    }
}

suspend fun updateFunctionCode(
    functionNameVal: String?,
    bucketName: String?,
    key: String?,
) {
    val functionCodeRequest =
        UpdateFunctionCodeRequest {
            functionName = functionNameVal
            publish = true
            s3Bucket = bucketName
            s3Key = key
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val response = awsLambda.updateFunctionCode(functionCodeRequest)
        awsLambda.waitUntilFunctionUpdated {
            functionName = functionNameVal
        }
        println("The last modified value is " + response.lastModified)
    }
}

suspend fun updateFunctionConfiguration(
    functionNameVal: String?,
    handlerVal: String?,
) {
    val configurationRequest =
        UpdateFunctionConfigurationRequest {
            functionName = functionNameVal
            handler = handlerVal
            runtime = Runtime.Java17
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        awsLambda.updateFunctionConfiguration(configurationRequest)
    }
}

suspend fun delFunction(myFunctionName: String) {
    val request =
        DeleteFunctionRequest {
            functionName = myFunctionName
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        awsLambda.deleteFunction(request)
        println("$myFunctionName was deleted")
    }
}
```
+ For API details, see the following topics in *AWS SDK for Kotlin API reference*.
  + [CreateFunction](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [DeleteFunction](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [GetFunction](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [Invoke](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [ListFunctions](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [UpdateFunctionCode](https://sdk.amazonaws.com/kotlin/api/latest/index.html)
  + [UpdateFunctionConfiguration](https://sdk.amazonaws.com/kotlin/api/latest/index.html)

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
namespace Lambda;

use Aws\S3\S3Client;
use GuzzleHttp\Psr7\Stream;
use Iam\IAMService;

class GettingStartedWithLambda
{
    public function run()
    {
        echo("\n");
        echo("--------------------------------------\n");
        print("Welcome to the AWS Lambda getting started demo using PHP!\n");
        echo("--------------------------------------\n");

        $clientArgs = [
            'region' => 'us-west-2',
            'version' => 'latest',
            'profile' => 'default',
        ];
        $uniqid = uniqid();

        $iamService = new IAMService();
        $s3client = new S3Client($clientArgs);
        $lambdaService = new LambdaService();

        echo "First, let's create a role to run our Lambda code.\n";
        $roleName = "test-lambda-role-$uniqid";
        $rolePolicyDocument = "{
            \"Version\": \"2012-10-17\",
            \"Statement\": [
                {
                    \"Effect\": \"Allow\",
                    \"Principal\": {
                        \"Service\": \"lambda.amazonaws.com\"
                    },
                    \"Action\": \"sts:AssumeRole\"
                }
            ]
        }";
        $role = $iamService->createRole($roleName, $rolePolicyDocument);
        echo "Created role {$role['RoleName']}.\n";

        $iamService->attachRolePolicy(
            $role['RoleName'],
            "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        );
        echo "Attached the AWSLambdaBasicExecutionRole to {$role['RoleName']}.\n";

        echo "\nNow let's create an S3 bucket and upload our Lambda code there.\n";
        $bucketName = "amzn-s3-demo-bucket-$uniqid";
        $s3client->createBucket([
            'Bucket' => $bucketName,
        ]);
        echo "Created bucket $bucketName.\n";

        $functionName = "doc_example_lambda_$uniqid";
        $codeBasic = __DIR__ . "/lambda_handler_basic.zip";
        $handler = "lambda_handler_basic";
        $file = file_get_contents($codeBasic);
        $s3client->putObject([
            'Bucket' => $bucketName,
            'Key' => $functionName,
            'Body' => $file,
        ]);
        echo "Uploaded the Lambda code.\n";

        $createLambdaFunction = $lambdaService->createFunction($functionName, $role, $bucketName, $handler);
        // Wait until the function has finished being created.
        do {
            $getLambdaFunction = $lambdaService->getFunction($createLambdaFunction['FunctionName']);
        } while ($getLambdaFunction['Configuration']['State'] == "Pending");
        echo "Created Lambda function {$getLambdaFunction['Configuration']['FunctionName']}.\n";

        sleep(1);

        echo "\nOk, let's invoke that Lambda code.\n";
        $basicParams = [
            'action' => 'increment',
            'number' => 3,
        ];
        /** @var Stream $invokeFunction */
        $invokeFunction = $lambdaService->invoke($functionName, $basicParams)['Payload'];
        $result = json_decode($invokeFunction->getContents())->result;
        echo "After invoking the Lambda code with the input of {$basicParams['number']} we received $result.\n";

        echo "\nSince that's working, let's update the Lambda code.\n";
        $codeCalculator = "lambda_handler_calculator.zip";
        $handlerCalculator = "lambda_handler_calculator";
        echo "First, put the new code into the S3 bucket.\n";
        $file = file_get_contents($codeCalculator);
        $s3client->putObject([
            'Bucket' => $bucketName,
            'Key' => $functionName,
            'Body' => $file,
        ]);
        echo "New code uploaded.\n";

        $lambdaService->updateFunctionCode($functionName, $bucketName, $functionName);
        // Wait for the Lambda code to finish updating.
        do {
            $getLambdaFunction = $lambdaService->getFunction($createLambdaFunction['FunctionName']);
        } while ($getLambdaFunction['Configuration']['LastUpdateStatus'] !== "Successful");
        echo "New Lambda code uploaded.\n";

        $environment = [
            'Variable' => ['Variables' => ['LOG_LEVEL' => 'DEBUG']],
        ];
        $lambdaService->updateFunctionConfiguration($functionName, $handlerCalculator, $environment);
        do {
            $getLambdaFunction = $lambdaService->getFunction($createLambdaFunction['FunctionName']);
        } while ($getLambdaFunction['Configuration']['LastUpdateStatus'] !== "Successful");
        echo "Lambda code updated with new handler and a LOG_LEVEL of DEBUG for more information.\n";

        echo "Invoke the new code with some new data.\n";
        $calculatorParams = [
            'action' => 'plus',
            'x' => 5,
            'y' => 4,
        ];
        $invokeFunction = $lambdaService->invoke($functionName, $calculatorParams, "Tail");
        $result = json_decode($invokeFunction['Payload']->getContents())->result;
        echo "Indeed, {$calculatorParams['x']} + {$calculatorParams['y']} does equal $result.\n";
        echo "Here's the extra debug info: ";
        echo base64_decode($invokeFunction['LogResult']) . "\n";

        echo "\nBut what happens if you try to divide by zero?\n";
        $divZeroParams = [
            'action' => 'divide',
            'x' => 5,
            'y' => 0,
        ];
        $invokeFunction = $lambdaService->invoke($functionName, $divZeroParams, "Tail");
        $result = json_decode($invokeFunction['Payload']->getContents())->result;
        echo "You get a |$result| result.\n";
        echo "And an error message: ";
        echo base64_decode($invokeFunction['LogResult']) . "\n";

        echo "\nHere's all the Lambda functions you have in this Region:\n";
        $listLambdaFunctions = $lambdaService->listFunctions(5);
        $allLambdaFunctions = $listLambdaFunctions['Functions'];
        $next = $listLambdaFunctions->get('NextMarker');
        while ($next != false) {
            $listLambdaFunctions = $lambdaService->listFunctions(5, $next);
            $next = $listLambdaFunctions->get('NextMarker');
            $allLambdaFunctions = array_merge($allLambdaFunctions, $listLambdaFunctions['Functions']);
        }
        foreach ($allLambdaFunctions as $function) {
            echo "{$function['FunctionName']}\n";
        }

        echo "\n\nAnd don't forget to clean up your data!\n";

        $lambdaService->deleteFunction($functionName);
        echo "Deleted Lambda function.\n";
        $iamService->deleteRole($role['RoleName']);
        echo "Deleted Role.\n";
        $deleteObjects = $s3client->listObjectsV2([
            'Bucket' => $bucketName,
        ]);
        $deleteObjects = $s3client->deleteObjects([
            'Bucket' => $bucketName,
            'Delete' => [
                'Objects' => $deleteObjects['Contents'],
            ]
        ]);
        echo "Deleted all objects from the S3 bucket.\n";
        $s3client->deleteBucket(['Bucket' => $bucketName]);
        echo "Deleted the bucket.\n";
    }
}
```
+ For API details, see the following topics in *AWS SDK for PHP API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 
Define a Lambda handler that increments a number.  

```
import logging

logger = logging.getLogger()
logger.setLevel(logging.INFO)


def lambda_handler(event, context):
    """
    Accepts an action and a single number, performs the specified action on the number,
    and returns the result. The only allowable action is 'increment'.

    :param event: The event dict that contains the parameters sent when the function
                  is invoked.
    :param context: The context in which the function is called.
    :return: The result of the action.
    """
    result = None
    action = event.get("action")
    if action == "increment":
        result = event.get("number", 0) + 1
        logger.info("Calculated result of %s", result)
    else:
        logger.error("%s is not a valid action.", action)

    response = {"result": result}
    return response
```
Define a second Lambda handler that performs arithmetic operations.  

```
import logging
import os


logger = logging.getLogger()

# Define a list of Python lambda functions that are called by this AWS Lambda function.
ACTIONS = {
    "plus": lambda x, y: x + y,
    "minus": lambda x, y: x - y,
    "times": lambda x, y: x * y,
    "divided-by": lambda x, y: x / y,
}


def lambda_handler(event, context):
    """
    Accepts an action and two numbers, performs the specified action on the numbers,
    and returns the result.

    :param event: The event dict that contains the parameters sent when the function
                  is invoked.
    :param context: The context in which the function is called.
    :return: The result of the specified action.
    """
    # Set the log level based on a variable configured in the Lambda environment.
    logger.setLevel(os.environ.get("LOG_LEVEL", logging.INFO))
    logger.debug("Event: %s", event)

    action = event.get("action")
    func = ACTIONS.get(action)
    x = event.get("x")
    y = event.get("y")
    result = None
    try:
        if func is not None and x is not None and y is not None:
            result = func(x, y)
            logger.info("%s %s %s is %s", x, action, y, result)
        else:
            logger.error("I can't calculate %s %s %s.", x, action, y)
    except ZeroDivisionError:
        logger.warning("I can't divide %s by 0!", x)

    response = {"result": result}
    return response
```
Create functions that wrap Lambda actions.  

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    @staticmethod
    def create_deployment_package(source_file, destination_file):
        """
        Creates a Lambda deployment package in .zip format in an in-memory buffer. This
        buffer can be passed directly to Lambda when creating the function.

        :param source_file: The name of the file that contains the Lambda handler
                            function.
        :param destination_file: The name to give the file when it's deployed to Lambda.
        :return: The deployment package.
        """
        buffer = io.BytesIO()
        with zipfile.ZipFile(buffer, "w") as zipped:
            zipped.write(source_file, destination_file)
        buffer.seek(0)
        return buffer.read()

    def get_iam_role(self, iam_role_name):
        """
        Get an AWS Identity and Access Management (IAM) role.

        :param iam_role_name: The name of the role to retrieve.
        :return: The IAM role.
        """
        role = None
        try:
            temp_role = self.iam_resource.Role(iam_role_name)
            temp_role.load()
            role = temp_role
            logger.info("Got IAM role %s", role.name)
        except ClientError as err:
            if err.response["Error"]["Code"] == "NoSuchEntity":
                logger.info("IAM role %s does not exist.", iam_role_name)
            else:
                logger.error(
                    "Couldn't get IAM role %s. Here's why: %s: %s",
                    iam_role_name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return role

    def create_iam_role_for_lambda(self, iam_role_name):
        """
        Creates an IAM role that grants the Lambda function basic permissions. If a
        role with the specified name already exists, it is used for the demo.

        :param iam_role_name: The name of the role to create.
        :return: The role and a value that indicates whether the role is newly created.
        """
        role = self.get_iam_role(iam_role_name)
        if role is not None:
            return role, False

        lambda_assume_role_policy = {
            "Version":"2012-10-17",		 	 	 
            "Statement": [
                {
                    "Effect": "Allow",
                    "Principal": {"Service": "lambda.amazonaws.com"},
                    "Action": "sts:AssumeRole",
                }
            ],
        }
        policy_arn = "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"

        try:
            role = self.iam_resource.create_role(
                RoleName=iam_role_name,
                AssumeRolePolicyDocument=json.dumps(lambda_assume_role_policy),
            )
            logger.info("Created role %s.", role.name)
            role.attach_policy(PolicyArn=policy_arn)
            logger.info("Attached basic execution policy to role %s.", role.name)
        except ClientError as error:
            if error.response["Error"]["Code"] == "EntityAlreadyExists":
                role = self.iam_resource.Role(iam_role_name)
                logger.warning("The role %s already exists. Using it.", iam_role_name)
            else:
                logger.exception(
                    "Couldn't create role %s or attach policy %s.",
                    iam_role_name,
                    policy_arn,
                )
                raise

        return role, True

    def get_function(self, function_name):
        """
        Gets data about a Lambda function.

        :param function_name: The name of the function.
        :return: The function data.
        """
        response = None
        try:
            response = self.lambda_client.get_function(FunctionName=function_name)
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Function %s does not exist.", function_name)
            else:
                logger.error(
                    "Couldn't get function %s. Here's why: %s: %s",
                    function_name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return response


    def create_function(
        self, function_name, handler_name, iam_role, deployment_package
    ):
        """
        Deploys a Lambda function.

        :param function_name: The name of the Lambda function.
        :param handler_name: The fully qualified name of the handler function. This
                             must include the file name and the function name.
        :param iam_role: The IAM role to use for the function.
        :param deployment_package: The deployment package that contains the function
                                   code in .zip format.
        :return: The Amazon Resource Name (ARN) of the newly created function.
        """
        try:
            response = self.lambda_client.create_function(
                FunctionName=function_name,
                Description="AWS Lambda doc example",
                Runtime="python3.9",
                Role=iam_role.arn,
                Handler=handler_name,
                Code={"ZipFile": deployment_package},
                Publish=True,
            )
            function_arn = response["FunctionArn"]
            waiter = self.lambda_client.get_waiter("function_active_v2")
            waiter.wait(FunctionName=function_name)
            logger.info(
                "Created function '%s' with ARN: '%s'.",
                function_name,
                response["FunctionArn"],
            )
        except ClientError:
            logger.error("Couldn't create function %s.", function_name)
            raise
        else:
            return function_arn


    def delete_function(self, function_name):
        """
        Deletes a Lambda function.

        :param function_name: The name of the function to delete.
        """
        try:
            self.lambda_client.delete_function(FunctionName=function_name)
        except ClientError:
            logger.exception("Couldn't delete function %s.", function_name)
            raise


    def invoke_function(self, function_name, function_params, get_log=False):
        """
        Invokes a Lambda function.

        :param function_name: The name of the function to invoke.
        :param function_params: The parameters of the function as a dict. This dict
                                is serialized to JSON before it is sent to Lambda.
        :param get_log: When true, the last 4 KB of the execution log are included in
                        the response.
        :return: The response from the function invocation.
        """
        try:
            response = self.lambda_client.invoke(
                FunctionName=function_name,
                Payload=json.dumps(function_params),
                LogType="Tail" if get_log else "None",
            )
            logger.info("Invoked function %s.", function_name)
        except ClientError:
            logger.exception("Couldn't invoke function %s.", function_name)
            raise
        return response


    def update_function_code(self, function_name, deployment_package):
        """
        Updates the code for a Lambda function by submitting a .zip archive that contains
        the code for the function.

        :param function_name: The name of the function to update.
        :param deployment_package: The function code to update, packaged as bytes in
                                   .zip format.
        :return: Data about the update, including the status.
        """
        try:
            response = self.lambda_client.update_function_code(
                FunctionName=function_name, ZipFile=deployment_package
            )
        except ClientError as err:
            logger.error(
                "Couldn't update function %s. Here's why: %s: %s",
                function_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response


    def update_function_configuration(self, function_name, env_vars):
        """
        Updates the environment variables for a Lambda function.

        :param function_name: The name of the function to update.
        :param env_vars: A dict of environment variables to update.
        :return: Data about the update, including the status.
        """
        try:
            response = self.lambda_client.update_function_configuration(
                FunctionName=function_name, Environment={"Variables": env_vars}
            )
        except ClientError as err:
            logger.error(
                "Couldn't update function configuration %s. Here's why: %s: %s",
                function_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response


    def list_functions(self):
        """
        Lists the Lambda functions for the current account.
        """
        try:
            func_paginator = self.lambda_client.get_paginator("list_functions")
            for func_page in func_paginator.paginate():
                for func in func_page["Functions"]:
                    print(func["FunctionName"])
                    desc = func.get("Description")
                    if desc:
                        print(f"\t{desc}")
                    print(f"\t{func['Runtime']}: {func['Handler']}")
        except ClientError as err:
            logger.error(
                "Couldn't list functions. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
```
Create a function that runs the scenario.  

```
class UpdateFunctionWaiter(CustomWaiter):
    """A custom waiter that waits until a function is successfully updated."""

    def __init__(self, client):
        super().__init__(
            "UpdateSuccess",
            "GetFunction",
            "Configuration.LastUpdateStatus",
            {"Successful": WaitState.SUCCESS, "Failed": WaitState.FAILURE},
            client,
        )

    def wait(self, function_name):
        self._wait(FunctionName=function_name)


def run_scenario(lambda_client, iam_resource, basic_file, calculator_file, lambda_name):
    """
    Runs the scenario.

    :param lambda_client: A Boto3 Lambda client.
    :param iam_resource: A Boto3 IAM resource.
    :param basic_file: The name of the file that contains the basic Lambda handler.
    :param calculator_file: The name of the file that contains the calculator Lambda handler.
    :param lambda_name: The name to give resources created for the scenario, such as the
                        IAM role and the Lambda function.
    """
    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    print("-" * 88)
    print("Welcome to the AWS Lambda getting started with functions demo.")
    print("-" * 88)

    wrapper = LambdaWrapper(lambda_client, iam_resource)

    print("Checking for IAM role for Lambda...")
    iam_role, should_wait = wrapper.create_iam_role_for_lambda(lambda_name)
    if should_wait:
        logger.info("Giving AWS time to create resources...")
        wait(10)

    print(f"Looking for function {lambda_name}...")
    function = wrapper.get_function(lambda_name)
    if function is None:
        print("Zipping the Python script into a deployment package...")
        deployment_package = wrapper.create_deployment_package(
            basic_file, f"{lambda_name}.py"
        )
        print(f"...and creating the {lambda_name} Lambda function.")
        wrapper.create_function(
            lambda_name, f"{lambda_name}.lambda_handler", iam_role, deployment_package
        )
    else:
        print(f"Function {lambda_name} already exists.")
    print("-" * 88)

    print(f"Let's invoke {lambda_name}. This function increments a number.")
    action_params = {
        "action": "increment",
        "number": q.ask("Give me a number to increment: ", q.is_int),
    }
    print(f"Invoking {lambda_name}...")
    response = wrapper.invoke_function(lambda_name, action_params)
    print(
        f"Incrementing {action_params['number']} resulted in "
        f"{json.load(response['Payload'])}"
    )
    print("-" * 88)

    print(f"Let's update the function to an arithmetic calculator.")
    q.ask("Press Enter when you're ready.")
    print("Creating a new deployment package...")
    deployment_package = wrapper.create_deployment_package(
        calculator_file, f"{lambda_name}.py"
    )
    print(f"...and updating the {lambda_name} Lambda function.")
    update_waiter = UpdateFunctionWaiter(lambda_client)
    wrapper.update_function_code(lambda_name, deployment_package)
    update_waiter.wait(lambda_name)
    print(f"This function uses an environment variable to control logging level.")
    print(f"Let's set it to DEBUG to get the most logging.")
    wrapper.update_function_configuration(
        lambda_name, {"LOG_LEVEL": logging.getLevelName(logging.DEBUG)}
    )

    actions = ["plus", "minus", "times", "divided-by"]
    want_invoke = True
    while want_invoke:
        print(f"Let's invoke {lambda_name}. You can invoke these actions:")
        for index, action in enumerate(actions):
            print(f"{index + 1}: {action}")
        action_params = {}
        action_index = q.ask(
            "Enter the number of the action you want to take: ",
            q.is_int,
            q.in_range(1, len(actions)),
        )
        action_params["action"] = actions[action_index - 1]
        print(f"You've chosen to invoke 'x {action_params['action']} y'.")
        action_params["x"] = q.ask("Enter a value for x: ", q.is_int)
        action_params["y"] = q.ask("Enter a value for y: ", q.is_int)
        print(f"Invoking {lambda_name}...")
        response = wrapper.invoke_function(lambda_name, action_params, True)
        print(
            f"Calculating {action_params['x']} {action_params['action']} {action_params['y']} "
            f"resulted in {json.load(response['Payload'])}"
        )
        q.ask("Press Enter to see the logs from the call.")
        print(base64.b64decode(response["LogResult"]).decode())
        want_invoke = q.ask("That was fun. Shall we do it again? (y/n) ", q.is_yesno)
    print("-" * 88)

    if q.ask(
        "Do you want to list all of the functions in your account? (y/n) ", q.is_yesno
    ):
        wrapper.list_functions()
    print("-" * 88)

    if q.ask("Ready to delete the function and role? (y/n) ", q.is_yesno):
        for policy in iam_role.attached_policies.all():
            policy.detach_role(RoleName=iam_role.name)
        iam_role.delete()
        print(f"Deleted role {lambda_name}.")
        wrapper.delete_function(lambda_name)
        print(f"Deleted function {lambda_name}.")

    print("\nThanks for watching!")
    print("-" * 88)


if __name__ == "__main__":
    try:
        run_scenario(
            boto3.client("lambda"),
            boto3.resource("iam"),
            "lambda_handler_basic.py",
            "lambda_handler_calculator.py",
            "doc_example_lambda_calculator",
        )
    except Exception:
        logging.exception("Something went wrong with the demo!")
```
+ For API details, see the following topics in *AWS SDK for Python (Boto3) API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 
Set up pre-requisite IAM permissions for a Lambda function capable of writing logs.  

```
  # Get an AWS Identity and Access Management (IAM) role.
  #
  # @param iam_role_name: The name of the role to retrieve.
  # @param action: Whether to create or destroy the IAM apparatus.
  # @return: The IAM role.
  def manage_iam(iam_role_name, action)
    case action
    when 'create'
      create_iam_role(iam_role_name)
    when 'destroy'
      destroy_iam_role(iam_role_name)
    else
      raise "Incorrect action provided. Must provide 'create' or 'destroy'"
    end
  end

  private

  def create_iam_role(iam_role_name)
    role_policy = {
      'Version': '2012-10-17',
      'Statement': [
        {
          'Effect': 'Allow',
          'Principal': { 'Service': 'lambda.amazonaws.com' },
          'Action': 'sts:AssumeRole'
        }
      ]
    }
    role = @iam_client.create_role(
      role_name: iam_role_name,
      assume_role_policy_document: role_policy.to_json
    )
    @iam_client.attach_role_policy(
      {
        policy_arn: 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole',
        role_name: iam_role_name
      }
    )
    wait_for_role_to_exist(iam_role_name)
    @logger.debug("Successfully created IAM role: #{role['role']['arn']}")
    sleep(10)
    [role, role_policy.to_json]
  end

  def destroy_iam_role(iam_role_name)
    @iam_client.detach_role_policy(
      {
        policy_arn: 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole',
        role_name: iam_role_name
      }
    )
    @iam_client.delete_role(role_name: iam_role_name)
    @logger.debug("Detached policy & deleted IAM role: #{iam_role_name}")
  end

  def wait_for_role_to_exist(iam_role_name)
    @iam_client.wait_until(:role_exists, { role_name: iam_role_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
  end
```
Define a Lambda handler that increments a number provided as an invocation parameter.  

```
require 'logger'

# A function that increments a whole number by one (1) and logs the result.
# Requires a manually-provided runtime parameter, 'number', which must be Int
#
# @param event [Hash] Parameters sent when the function is invoked
# @param context [Hash] Methods and properties that provide information
# about the invocation, function, and execution environment.
# @return incremented_number [String] The incremented number.
def lambda_handler(event:, context:)
  logger = Logger.new($stdout)
  log_level = ENV['LOG_LEVEL']
  logger.level = case log_level
                 when 'debug'
                   Logger::DEBUG
                 when 'info'
                   Logger::INFO
                 else
                   Logger::ERROR
                 end
  logger.debug('This is a debug log message.')
  logger.info('This is an info log message. Code executed successfully!')
  number = event['number'].to_i
  incremented_number = number + 1
  logger.info("You provided #{number.round} and it was incremented to #{incremented_number.round}")
  incremented_number.round.to_s
end
```
Zip your Lambda function into a deployment package.  

```
  # Creates a Lambda deployment package in .zip format.
  #
  # @param source_file: The name of the object, without suffix, for the Lambda file and zip.
  # @return: The deployment package.
  def create_deployment_package(source_file)
    Dir.chdir(File.dirname(__FILE__))
    if File.exist?('lambda_function.zip')
      File.delete('lambda_function.zip')
      @logger.debug('Deleting old zip: lambda_function.zip')
    end
    Zip::File.open('lambda_function.zip', create: true) do |zipfile|
      zipfile.add('lambda_function.rb', "#{source_file}.rb")
    end
    @logger.debug("Zipping #{source_file}.rb into: lambda_function.zip.")
    File.read('lambda_function.zip').to_s
  rescue StandardError => e
    @logger.error("There was an error creating deployment package:\n #{e.message}")
  end
```
Create a new Lambda function.  

```
  # Deploys a Lambda function.
  #
  # @param function_name: The name of the Lambda function.
  # @param handler_name: The fully qualified name of the handler function.
  # @param role_arn: The IAM role to use for the function.
  # @param deployment_package: The deployment package that contains the function code in .zip format.
  # @return: The Amazon Resource Name (ARN) of the newly created function.
  def create_function(function_name, handler_name, role_arn, deployment_package)
    response = @lambda_client.create_function({
                                                role: role_arn.to_s,
                                                function_name: function_name,
                                                handler: handler_name,
                                                runtime: 'ruby2.7',
                                                code: {
                                                  zip_file: deployment_package
                                                },
                                                environment: {
                                                  variables: {
                                                    'LOG_LEVEL' => 'info'
                                                  }
                                                }
                                              })
    @lambda_client.wait_until(:function_active_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
    response
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error creating #{function_name}:\n #{e.message}")
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
  end
```
Invoke your Lambda function with optional runtime parameters.  

```
  # Invokes a Lambda function.
  # @param function_name [String] The name of the function to invoke.
  # @param payload [nil] Payload containing runtime parameters.
  # @return [Object] The response from the function invocation.
  def invoke_function(function_name, payload = nil)
    params = { function_name: function_name }
    params[:payload] = payload unless payload.nil?
    @lambda_client.invoke(params)
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error executing #{function_name}:\n #{e.message}")
  end
```
Update your Lambda function's configuration to inject a new environment variable.  

```
  # Updates the environment variables for a Lambda function.
  # @param function_name: The name of the function to update.
  # @param log_level: The log level of the function.
  # @return: Data about the update, including the status.
  def update_function_configuration(function_name, log_level)
    @lambda_client.update_function_configuration({
                                                   function_name: function_name,
                                                   environment: {
                                                     variables: {
                                                       'LOG_LEVEL' => log_level
                                                     }
                                                   }
                                                 })
    @lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error updating configurations for #{function_name}:\n #{e.message}")
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
  end
```
Update your Lambda function's code with a different deployment package containing different code.  

```
  # Updates the code for a Lambda function by submitting a .zip archive that contains
  # the code for the function.
  #
  # @param function_name: The name of the function to update.
  # @param deployment_package: The function code to update, packaged as bytes in
  #                            .zip format.
  # @return: Data about the update, including the status.
  def update_function_code(function_name, deployment_package)
    @lambda_client.update_function_code(
      function_name: function_name,
      zip_file: deployment_package
    )
    @lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error updating function code for: #{function_name}:\n #{e.message}")
    nil
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to update:\n #{e.message}")
  end
```
List all existing Lambda functions using the built-in paginator.  

```
  # Lists the Lambda functions for the current account.
  def list_functions
    functions = []
    @lambda_client.list_functions.each do |response|
      response['functions'].each do |function|
        functions.append(function['function_name'])
      end
    end
    functions
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error listing functions:\n #{e.message}")
  end
```
Delete a specific Lambda function.  

```
  # Deletes a Lambda function.
  # @param function_name: The name of the function to delete.
  def delete_function(function_name)
    print "Deleting function: #{function_name}..."
    @lambda_client.delete_function(
      function_name: function_name
    )
    print 'Done!'.green
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error deleting #{function_name}:\n #{e.message}")
  end
```
+ For API details, see the following topics in *AWS SDK for Ruby API Reference*.
  + [CreateFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/CreateFunction)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/DeleteFunction)
  + [GetFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/GetFunction)
  + [Invoke](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/Invoke)
  + [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionCode)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionConfiguration)

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 
The Cargo.toml with dependencies used in this scenario.  

```
[package]
name = "lambda-code-examples"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
aws-config = { version = "1.0.1", features = ["behavior-version-latest"] }
aws-sdk-ec2 = { version = "1.3.0" }
aws-sdk-iam = { version = "1.3.0" }
aws-sdk-lambda = { version = "1.3.0" }
aws-sdk-s3 = { version = "1.4.0" }
aws-smithy-types = { version = "1.0.1" }
aws-types = { version = "1.0.1" }
clap = { version = "4.4", features = ["derive"] }
tokio = { version = "1.20.1", features = ["full"] }
tracing-subscriber = { version = "0.3.15", features = ["env-filter"] }
tracing = "0.1.37"
serde_json = "1.0.94"
anyhow = "1.0.71"
uuid = { version = "1.3.3", features = ["v4"] }
lambda_runtime = "0.8.0"
serde = "1.0.164"
```
A collection of utilities that streamline calling Lambda for this scenario. This file is src/ations.rs in the crate.  

```
use anyhow::anyhow;
use aws_sdk_iam::operation::{create_role::CreateRoleError, delete_role::DeleteRoleOutput};
use aws_sdk_lambda::{
    operation::{
        delete_function::DeleteFunctionOutput, get_function::GetFunctionOutput,
        invoke::InvokeOutput, list_functions::ListFunctionsOutput,
        update_function_code::UpdateFunctionCodeOutput,
        update_function_configuration::UpdateFunctionConfigurationOutput,
    },
    primitives::ByteStream,
    types::{Environment, FunctionCode, LastUpdateStatus, State},
};
use aws_sdk_s3::{
    error::ErrorMetadata,
    operation::{delete_bucket::DeleteBucketOutput, delete_object::DeleteObjectOutput},
    types::CreateBucketConfiguration,
};
use aws_smithy_types::Blob;
use serde::{ser::SerializeMap, Serialize};
use std::{fmt::Display, path::PathBuf, str::FromStr, time::Duration};
use tracing::{debug, info, warn};

/* Operation describes  */
#[derive(Clone, Copy, Debug, Serialize)]
pub enum Operation {
    #[serde(rename = "plus")]
    Plus,
    #[serde(rename = "minus")]
    Minus,
    #[serde(rename = "times")]
    Times,
    #[serde(rename = "divided-by")]
    DividedBy,
}

impl FromStr for Operation {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "plus" => Ok(Operation::Plus),
            "minus" => Ok(Operation::Minus),
            "times" => Ok(Operation::Times),
            "divided-by" => Ok(Operation::DividedBy),
            _ => Err(anyhow!("Unknown operation {s}")),
        }
    }
}

impl Display for Operation {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Operation::Plus => write!(f, "plus"),
            Operation::Minus => write!(f, "minus"),
            Operation::Times => write!(f, "times"),
            Operation::DividedBy => write!(f, "divided-by"),
        }
    }
}

/**
 * InvokeArgs will be serialized as JSON and sent to the AWS Lambda handler.
 */
#[derive(Debug)]
pub enum InvokeArgs {
    Increment(i32),
    Arithmetic(Operation, i32, i32),
}

impl Serialize for InvokeArgs {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: serde::Serializer,
    {
        match self {
            InvokeArgs::Increment(i) => serializer.serialize_i32(*i),
            InvokeArgs::Arithmetic(o, i, j) => {
                let mut map: S::SerializeMap = serializer.serialize_map(Some(3))?;
                map.serialize_key(&"op".to_string())?;
                map.serialize_value(&o.to_string())?;
                map.serialize_key(&"i".to_string())?;
                map.serialize_value(&i)?;
                map.serialize_key(&"j".to_string())?;
                map.serialize_value(&j)?;
                map.end()
            }
        }
    }
}

/** A policy document allowing Lambda to execute this function on the account's behalf. */
const ROLE_POLICY_DOCUMENT: &str = r#"{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": { "Service": "lambda.amazonaws.com" },
            "Action": "sts:AssumeRole"
        }
    ]
}"#;

/**
 * A LambdaManager gathers all the resources necessary to run the Lambda example scenario.
 * This includes instantiated aws_sdk clients and details of resource names.
 */
pub struct LambdaManager {
    iam_client: aws_sdk_iam::Client,
    lambda_client: aws_sdk_lambda::Client,
    s3_client: aws_sdk_s3::Client,
    lambda_name: String,
    role_name: String,
    bucket: String,
    own_bucket: bool,
}

// These unit type structs provide nominal typing on top of String parameters for LambdaManager::new
pub struct LambdaName(pub String);
pub struct RoleName(pub String);
pub struct Bucket(pub String);
pub struct OwnBucket(pub bool);

impl LambdaManager {
    pub fn new(
        iam_client: aws_sdk_iam::Client,
        lambda_client: aws_sdk_lambda::Client,
        s3_client: aws_sdk_s3::Client,
        lambda_name: LambdaName,
        role_name: RoleName,
        bucket: Bucket,
        own_bucket: OwnBucket,
    ) -> Self {
        Self {
            iam_client,
            lambda_client,
            s3_client,
            lambda_name: lambda_name.0,
            role_name: role_name.0,
            bucket: bucket.0,
            own_bucket: own_bucket.0,
        }
    }

    /**
     * Load the AWS configuration from the environment.
     * Look up lambda_name and bucket if none are given, or generate a random name if not present in the environment.
     * If the bucket name is provided, the caller needs to have created the bucket.
     * If the bucket name is generated, it will be created.
     */
    pub async fn load_from_env(lambda_name: Option<String>, bucket: Option<String>) -> Self {
        let sdk_config = aws_config::load_from_env().await;
        let lambda_name = LambdaName(lambda_name.unwrap_or_else(|| {
            std::env::var("LAMBDA_NAME").unwrap_or_else(|_| "rust_lambda_example".to_string())
        }));
        let role_name = RoleName(format!("{}_role", lambda_name.0));
        let (bucket, own_bucket) =
            match bucket {
                Some(bucket) => (Bucket(bucket), false),
                None => (
                    Bucket(std::env::var("LAMBDA_BUCKET").unwrap_or_else(|_| {
                        format!("rust-lambda-example-{}", uuid::Uuid::new_v4())
                    })),
                    true,
                ),
            };

        let s3_client = aws_sdk_s3::Client::new(&sdk_config);

        if own_bucket {
            info!("Creating bucket for demo: {}", bucket.0);
            s3_client
                .create_bucket()
                .bucket(bucket.0.clone())
                .create_bucket_configuration(
                    CreateBucketConfiguration::builder()
                        .location_constraint(aws_sdk_s3::types::BucketLocationConstraint::from(
                            sdk_config.region().unwrap().as_ref(),
                        ))
                        .build(),
                )
                .send()
                .await
                .unwrap();
        }

        Self::new(
            aws_sdk_iam::Client::new(&sdk_config),
            aws_sdk_lambda::Client::new(&sdk_config),
            s3_client,
            lambda_name,
            role_name,
            bucket,
            OwnBucket(own_bucket),
        )
    }

    /**
     * Upload function code from a path to a zip file.
     * The zip file must have an AL2 Linux-compatible binary called `bootstrap`.
     * The easiest way to create such a zip is to use `cargo lambda build --output-format Zip`.
     */
    async fn prepare_function(
        &self,
        zip_file: PathBuf,
        key: Option<String>,
    ) -> Result<FunctionCode, anyhow::Error> {
        let body = ByteStream::from_path(zip_file).await?;

        let key = key.unwrap_or_else(|| format!("{}_code", self.lambda_name));

        info!("Uploading function code to s3://{}/{}", self.bucket, key);
        let _ = self
            .s3_client
            .put_object()
            .bucket(self.bucket.clone())
            .key(key.clone())
            .body(body)
            .send()
            .await?;

        Ok(FunctionCode::builder()
            .s3_bucket(self.bucket.clone())
            .s3_key(key)
            .build())
    }

    /**
     * Create a function, uploading from a zip file.
     */
    pub async fn create_function(&self, zip_file: PathBuf) -> Result<String, anyhow::Error> {
        let code = self.prepare_function(zip_file, None).await?;

        let key = code.s3_key().unwrap().to_string();

        let role = self.create_role().await.map_err(|e| anyhow!(e))?;

        info!("Created iam role, waiting 15s for it to become active");
        tokio::time::sleep(Duration::from_secs(15)).await;

        info!("Creating lambda function {}", self.lambda_name);
        let _ = self
            .lambda_client
            .create_function()
            .function_name(self.lambda_name.clone())
            .code(code)
            .role(role.arn())
            .runtime(aws_sdk_lambda::types::Runtime::Providedal2)
            .handler("_unused")
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        self.lambda_client
            .publish_version()
            .function_name(self.lambda_name.clone())
            .send()
            .await?;

        Ok(key)
    }

    /**
     * Create an IAM execution role for the managed Lambda function.
     * If the role already exists, use that instead.
     */
    async fn create_role(&self) -> Result<aws_sdk_iam::types::Role, CreateRoleError> {
        info!("Creating execution role for function");
        let get_role = self
            .iam_client
            .get_role()
            .role_name(self.role_name.clone())
            .send()
            .await;
        if let Ok(get_role) = get_role {
            if let Some(role) = get_role.role {
                return Ok(role);
            }
        }

        let create_role = self
            .iam_client
            .create_role()
            .role_name(self.role_name.clone())
            .assume_role_policy_document(ROLE_POLICY_DOCUMENT)
            .send()
            .await;

        match create_role {
            Ok(create_role) => match create_role.role {
                Some(role) => Ok(role),
                None => Err(CreateRoleError::generic(
                    ErrorMetadata::builder()
                        .message("CreateRole returned empty success")
                        .build(),
                )),
            },
            Err(err) => Err(err.into_service_error()),
        }
    }

    /**
     * Poll `is_function_ready` with a 1-second delay. It returns when the function is ready or when there's an error checking the function's state.
     */
    pub async fn wait_for_function_ready(&self) -> Result<(), anyhow::Error> {
        info!("Waiting for function");
        while !self.is_function_ready(None).await? {
            info!("Function is not ready, sleeping 1s");
            tokio::time::sleep(Duration::from_secs(1)).await;
        }
        Ok(())
    }

    /**
     * Check if a Lambda function is ready to be invoked.
     * A Lambda function is ready for this scenario when its state is active and its LastUpdateStatus is Successful.
     * Additionally, if a sha256 is provided, the function must have that as its current code hash.
     * Any missing properties or failed requests will be reported as an Err.
     */
    async fn is_function_ready(
        &self,
        expected_code_sha256: Option<&str>,
    ) -> Result<bool, anyhow::Error> {
        match self.get_function().await {
            Ok(func) => {
                if let Some(config) = func.configuration() {
                    if let Some(state) = config.state() {
                        info!(?state, "Checking if function is active");
                        if !matches!(state, State::Active) {
                            return Ok(false);
                        }
                    }
                    match config.last_update_status() {
                        Some(last_update_status) => {
                            info!(?last_update_status, "Checking if function is ready");
                            match last_update_status {
                                LastUpdateStatus::Successful => {
                                    // continue
                                }
                                LastUpdateStatus::Failed | LastUpdateStatus::InProgress => {
                                    return Ok(false);
                                }
                                unknown => {
                                    warn!(
                                        status_variant = unknown.as_str(),
                                        "LastUpdateStatus unknown"
                                    );
                                    return Err(anyhow!(
                                        "Unknown LastUpdateStatus, fn config is {config:?}"
                                    ));
                                }
                            }
                        }
                        None => {
                            warn!("Missing last update status");
                            return Ok(false);
                        }
                    };
                    if expected_code_sha256.is_none() {
                        return Ok(true);
                    }
                    if let Some(code_sha256) = config.code_sha256() {
                        return Ok(code_sha256 == expected_code_sha256.unwrap_or_default());
                    }
                }
            }
            Err(e) => {
                warn!(?e, "Could not get function while waiting");
            }
        }
        Ok(false)
    }

    /** Get the Lambda function with this Manager's name. */
    pub async fn get_function(&self) -> Result<GetFunctionOutput, anyhow::Error> {
        info!("Getting lambda function");
        self.lambda_client
            .get_function()
            .function_name(self.lambda_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

    /** List all Lambda functions in the current Region. */
    pub async fn list_functions(&self) -> Result<ListFunctionsOutput, anyhow::Error> {
        info!("Listing lambda functions");
        self.lambda_client
            .list_functions()
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

    /** Invoke the lambda function using calculator InvokeArgs. */
    pub async fn invoke(&self, args: InvokeArgs) -> Result<InvokeOutput, anyhow::Error> {
        info!(?args, "Invoking {}", self.lambda_name);
        let payload = serde_json::to_string(&args)?;
        debug!(?payload, "Sending payload");
        self.lambda_client
            .invoke()
            .function_name(self.lambda_name.clone())
            .payload(Blob::new(payload))
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

    /** Given a Path to a zip file, update the function's code and wait for the update to finish. */
    pub async fn update_function_code(
        &self,
        zip_file: PathBuf,
        key: String,
    ) -> Result<UpdateFunctionCodeOutput, anyhow::Error> {
        let function_code = self.prepare_function(zip_file, Some(key)).await?;

        info!("Updating code for {}", self.lambda_name);
        let update = self
            .lambda_client
            .update_function_code()
            .function_name(self.lambda_name.clone())
            .s3_bucket(self.bucket.clone())
            .s3_key(function_code.s3_key().unwrap().to_string())
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        Ok(update)
    }

    /** Update the environment for a function. */
    pub async fn update_function_configuration(
        &self,
        environment: Environment,
    ) -> Result<UpdateFunctionConfigurationOutput, anyhow::Error> {
        info!(
            ?environment,
            "Updating environment for {}", self.lambda_name
        );
        let updated = self
            .lambda_client
            .update_function_configuration()
            .function_name(self.lambda_name.clone())
            .environment(environment)
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        Ok(updated)
    }

    /** Delete a function and its role, and if possible or necessary, its associated code object and bucket. */
    pub async fn delete_function(
        &self,
        location: Option<String>,
    ) -> (
        Result<DeleteFunctionOutput, anyhow::Error>,
        Result<DeleteRoleOutput, anyhow::Error>,
        Option<Result<DeleteObjectOutput, anyhow::Error>>,
    ) {
        info!("Deleting lambda function {}", self.lambda_name);
        let delete_function = self
            .lambda_client
            .delete_function()
            .function_name(self.lambda_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from);

        info!("Deleting iam role {}", self.role_name);
        let delete_role = self
            .iam_client
            .delete_role()
            .role_name(self.role_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from);

        let delete_object: Option<Result<DeleteObjectOutput, anyhow::Error>> =
            if let Some(location) = location {
                info!("Deleting object {location}");
                Some(
                    self.s3_client
                        .delete_object()
                        .bucket(self.bucket.clone())
                        .key(location)
                        .send()
                        .await
                        .map_err(anyhow::Error::from),
                )
            } else {
                info!(?location, "Skipping delete object");
                None
            };

        (delete_function, delete_role, delete_object)
    }

    pub async fn cleanup(
        &self,
        location: Option<String>,
    ) -> (
        (
            Result<DeleteFunctionOutput, anyhow::Error>,
            Result<DeleteRoleOutput, anyhow::Error>,
            Option<Result<DeleteObjectOutput, anyhow::Error>>,
        ),
        Option<Result<DeleteBucketOutput, anyhow::Error>>,
    ) {
        let delete_function = self.delete_function(location).await;

        let delete_bucket = if self.own_bucket {
            info!("Deleting bucket {}", self.bucket);
            if delete_function.2.is_none() || delete_function.2.as_ref().unwrap().is_ok() {
                Some(
                    self.s3_client
                        .delete_bucket()
                        .bucket(self.bucket.clone())
                        .send()
                        .await
                        .map_err(anyhow::Error::from),
                )
            } else {
                None
            }
        } else {
            info!("No bucket to clean up");
            None
        };

        (delete_function, delete_bucket)
    }
}

/**
 * Testing occurs primarily as an integration test running the `scenario` bin successfully.
 * Each action relies deeply on the internal workings and state of Amazon Simple Storage Service (Amazon S3), Lambda, and IAM working together.
 * It is therefore infeasible to mock the clients to test the individual actions.
 */
#[cfg(test)]
mod test {
    use super::{InvokeArgs, Operation};
    use serde_json::json;

    /** Make sure that the JSON output of serializing InvokeArgs is what's expected by the calculator. */
    #[test]
    fn test_serialize() {
        assert_eq!(json!(InvokeArgs::Increment(5)), 5);
        assert_eq!(
            json!(InvokeArgs::Arithmetic(Operation::Plus, 5, 7)).to_string(),
            r#"{"op":"plus","i":5,"j":7}"#.to_string(),
        );
    }
}
```
A binary to run the scenario from front to end, using command line flags to control some behavior. This file is src/bin/scenario.rs in the crate.  

```
/*
## Service actions

Service actions wrap the SDK call, taking a client and any specific parameters necessary for the call.

* CreateFunction
* GetFunction
* ListFunctions
* Invoke
* UpdateFunctionCode
* UpdateFunctionConfiguration
* DeleteFunction

## Scenario
A scenario runs at a command prompt and prints output to the user on the result of each service action. A scenario can run in one of two ways: straight through, printing out progress as it goes, or as an interactive question/answer script.

## Getting started with functions

Use an SDK to manage AWS Lambda functions: create a function, invoke it, update its code, invoke it again, view its output and logs, and delete it.

This scenario uses two Lambda handlers:
_Note: Handlers don't use AWS SDK API calls._

The increment handler is straightforward:

1. It accepts a number, increments it, and returns the new value.
2. It performs simple logging of the result.

The arithmetic handler is more complex:
1. It accepts a set of actions ['plus', 'minus', 'times', 'divided-by'] and two numbers, and returns the result of the calculation.
2. It uses an environment variable to control log level (such as DEBUG, INFO, WARNING, ERROR).
It logs a few things at different levels, such as:
    * DEBUG: Full event data.
    * INFO: The calculation result.
    * WARN~ING~: When a divide by zero error occurs.
    * This will be the typical `RUST_LOG` variable.


The steps of the scenario are:

1. Create an AWS Identity and Access Management (IAM) role that meets the following requirements:
    * Has an assume_role policy that grants 'lambda.amazonaws.com' the 'sts:AssumeRole' action.
    * Attaches the 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole' managed role.
    * _You must wait for ~10 seconds after the role is created before you can use it!_
2. Create a function (CreateFunction) for the increment handler by packaging it as a zip and doing one of the following:
    * Adding it with CreateFunction Code.ZipFile.
    * --or--
    * Uploading it to Amazon Simple Storage Service (Amazon S3) and adding it with CreateFunction Code.S3Bucket/S3Key.
    * _Note: Zipping the file does not have to be done in code._
    * If you have a waiter, use it to wait until the function is active. Otherwise, call GetFunction until State is Active.
3. Invoke the function with a number and print the result.
4. Update the function (UpdateFunctionCode) to the arithmetic handler by packaging it as a zip and doing one of the following:
    * Adding it with UpdateFunctionCode ZipFile.
    * --or--
    * Uploading it to Amazon S3 and adding it with UpdateFunctionCode S3Bucket/S3Key.
5. Call GetFunction until Configuration.LastUpdateStatus is 'Successful' (or 'Failed').
6. Update the environment variable by calling UpdateFunctionConfiguration and pass it a log level, such as:
    * Environment={'Variables': {'RUST_LOG': 'TRACE'}}
7. Invoke the function with an action from the list and a couple of values. Include LogType='Tail' to get logs in the result. Print the result of the calculation and the log.
8. [Optional] Invoke the function to provoke a divide-by-zero error and show the log result.
9. List all functions for the account, using pagination (ListFunctions).
10. Delete the function (DeleteFunction).
11. Delete the role.

Each step should use the function created in Service Actions to abstract calling the SDK.
 */

use aws_sdk_lambda::{operation::invoke::InvokeOutput, types::Environment};
use clap::Parser;
use std::{collections::HashMap, path::PathBuf};
use tracing::{debug, info, warn};
use tracing_subscriber::EnvFilter;

use lambda_code_examples::actions::{
    InvokeArgs::{Arithmetic, Increment},
    LambdaManager, Operation,
};

#[derive(Debug, Parser)]
pub struct Opt {
    /// The AWS Region.
    #[structopt(short, long)]
    pub region: Option<String>,

    // The bucket to use for the FunctionCode.
    #[structopt(short, long)]
    pub bucket: Option<String>,

    // The name of the Lambda function.
    #[structopt(short, long)]
    pub lambda_name: Option<String>,

    // The number to increment.
    #[structopt(short, long, default_value = "12")]
    pub inc: i32,

    // The left operand.
    #[structopt(long, default_value = "19")]
    pub num_a: i32,

    // The right operand.
    #[structopt(long, default_value = "23")]
    pub num_b: i32,

    // The arithmetic operation.
    #[structopt(short, long, default_value = "plus")]
    pub operation: Operation,

    #[structopt(long)]
    pub cleanup: Option<bool>,

    #[structopt(long)]
    pub no_cleanup: Option<bool>,
}

fn code_path(lambda: &str) -> PathBuf {
    PathBuf::from(format!("../target/lambda/{lambda}/bootstrap.zip"))
}

fn log_invoke_output(invoke: &InvokeOutput, message: &str) {
    if let Some(payload) = invoke.payload().cloned() {
        let payload = String::from_utf8(payload.into_inner());
        info!(?payload, message);
    } else {
        info!("Could not extract payload")
    }
    if let Some(logs) = invoke.log_result() {
        debug!(?logs, "Invoked function logs")
    } else {
        debug!("Invoked function had no logs")
    }
}

async fn main_block(
    opt: &Opt,
    manager: &LambdaManager,
    code_location: String,
) -> Result<(), anyhow::Error> {
    let invoke = manager.invoke(Increment(opt.inc)).await?;
    log_invoke_output(&invoke, "Invoked function configured as increment");

    let update_code = manager
        .update_function_code(code_path("arithmetic"), code_location.clone())
        .await?;

    let code_sha256 = update_code.code_sha256().unwrap_or("Unknown SHA");
    info!(?code_sha256, "Updated function code with arithmetic.zip");

    let arithmetic_args = Arithmetic(opt.operation, opt.num_a, opt.num_b);
    let invoke = manager.invoke(arithmetic_args).await?;
    log_invoke_output(&invoke, "Invoked function configured as arithmetic");

    let update = manager
        .update_function_configuration(
            Environment::builder()
                .set_variables(Some(HashMap::from([(
                    "RUST_LOG".to_string(),
                    "trace".to_string(),
                )])))
                .build(),
        )
        .await?;
    let updated_environment = update.environment();
    info!(?updated_environment, "Updated function configuration");

    let invoke = manager
        .invoke(Arithmetic(opt.operation, opt.num_a, opt.num_b))
        .await?;
    log_invoke_output(
        &invoke,
        "Invoked function configured as arithmetic with increased logging",
    );

    let invoke = manager
        .invoke(Arithmetic(Operation::DividedBy, opt.num_a, 0))
        .await?;
    log_invoke_output(
        &invoke,
        "Invoked function configured as arithmetic with divide by zero",
    );

    Ok::<(), anyhow::Error>(())
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt()
        .without_time()
        .with_file(true)
        .with_line_number(true)
        .with_env_filter(EnvFilter::from_default_env())
        .init();

    let opt = Opt::parse();
    let manager = LambdaManager::load_from_env(opt.lambda_name.clone(), opt.bucket.clone()).await;

    let key = match manager.create_function(code_path("increment")).await {
        Ok(init) => {
            info!(?init, "Created function, initially with increment.zip");
            let run_block = main_block(&opt, &manager, init.clone()).await;
            info!(?run_block, "Finished running example, cleaning up");
            Some(init)
        }
        Err(err) => {
            warn!(?err, "Error happened when initializing function");
            None
        }
    };

    if Some(false) == opt.cleanup || Some(true) == opt.no_cleanup {
        info!("Skipping cleanup")
    } else {
        let delete = manager.cleanup(key).await;
        info!(?delete, "Deleted function & cleaned up resources");
    }
}
```
+ For API details, see the following topics in *AWS SDK for Rust API reference*.
  + [CreateFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.create_function)
  + [DeleteFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.delete_function)
  + [GetFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.get_function)
  + [Invoke](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.invoke)
  + [ListFunctions](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.list_functions)
  + [UpdateFunctionCode](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.update_function_code)
  + [UpdateFunctionConfiguration](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.update_function_configuration)

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        "Create an AWS Identity and Access Management (IAM) role that grants AWS Lambda permission to write to logs."
        DATA(lv_policy_document) = `{` &&
            `"Version":"2012-10-17",		 	 	 ` &&
                  `"Statement": [` &&
                    `{` &&
                      `"Effect": "Allow",` &&
                      `"Action": [` &&
                        `"sts:AssumeRole"` &&
                      `],` &&
                      `"Principal": {` &&
                        `"Service": [` &&
                          `"lambda.amazonaws.com"` &&
                        `]` &&
                      `}` &&
                    `}` &&
                  `]` &&
                `}`.
        TRY.
            DATA(lo_create_role_output) = lo_iam->createrole(
                    iv_rolename = iv_role_name
                    iv_assumerolepolicydocument = lv_policy_document
                    iv_description = 'Grant lambda permission to write to logs' ).
            DATA(lv_role_arn) = lo_create_role_output->get_role( )->get_arn( ).
            MESSAGE 'IAM role created.' TYPE 'I'.
            WAIT UP TO 10 SECONDS.            " Make sure that the IAM role is ready for use. "
          CATCH /aws1/cx_iamentityalrdyexex.
            DATA(lo_role) = lo_iam->getrole( iv_rolename = iv_role_name ).
            lv_role_arn = lo_role->get_role( )->get_arn( ).
          CATCH /aws1/cx_iaminvalidinputex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_iammalformedplydocex.
            MESSAGE 'Policy document in the request is malformed.' TYPE 'E'.
        ENDTRY.

        TRY.
            lo_iam->attachrolepolicy(
                iv_rolename  = iv_role_name
                iv_policyarn = 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole' ).
            MESSAGE 'Attached policy to the IAM role.' TYPE 'I'.
          CATCH /aws1/cx_iaminvalidinputex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_iamnosuchentityex.
            MESSAGE 'The requested resource entity does not exist.' TYPE 'E'.
          CATCH /aws1/cx_iamplynotattachableex.
            MESSAGE 'Service role policies can only be attached to the service-linked role for their service.' TYPE 'E'.
          CATCH /aws1/cx_iamunmodableentityex.
            MESSAGE 'Service that depends on the service-linked role is not modifiable.' TYPE 'E'.
        ENDTRY.

        " Create a Lambda function and upload handler code. "
        " Lambda function performs 'increment' action on a number. "
        TRY.
            lo_lmd->createfunction(
                 iv_functionname = iv_function_name
                 iv_runtime = `python3.9`
                 iv_role = lv_role_arn
                 iv_handler = iv_handler
                 io_code = io_initial_zip_file
                 iv_description = 'AWS Lambda code example' ).
            MESSAGE 'Lambda function created.' TYPE 'I'.
          CATCH /aws1/cx_lmdcodestorageexcdex.
            MESSAGE 'Maximum total code size per account exceeded.' TYPE 'E'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'E'.
        ENDTRY.

        " Verify the function is in Active state "
        WHILE lo_lmd->getfunction( iv_functionname = iv_function_name )->get_configuration( )->ask_state( ) <> 'Active'.
          IF sy-index = 10.
            EXIT.               " Maximum 10 seconds. "
          ENDIF.
          WAIT UP TO 1 SECONDS.
        ENDWHILE.

        "Invoke the function with a single parameter and get results."
        TRY.
            DATA(lv_json) = /aws1/cl_rt_util=>string_to_xstring(
              `{`  &&
                `"action": "increment",`  &&
                `"number": 10` &&
              `}` ).
            DATA(lo_initial_invoke_output) = lo_lmd->invoke(
                       iv_functionname = iv_function_name
                       iv_payload = lv_json ).
            ov_initial_invoke_payload = lo_initial_invoke_output->get_payload( ).           " ov_initial_invoke_payload is returned for testing purposes. "
            DATA(lo_writer_json) = cl_sxml_string_writer=>create( type = if_sxml=>co_xt_json ).
            CALL TRANSFORMATION id SOURCE XML ov_initial_invoke_payload RESULT XML lo_writer_json.
            DATA(lv_result) = cl_abap_codepage=>convert_from( lo_writer_json->get_output( ) ).
            MESSAGE 'Lambda function invoked.' TYPE 'I'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdinvrequestcontex.
            MESSAGE 'Unable to parse request body as JSON.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'E'.
          CATCH /aws1/cx_lmdunsuppedmediatyp00.
            MESSAGE 'Invoke request body does not have JSON as its content type.' TYPE 'E'.
        ENDTRY.

        " Update the function code and configure its Lambda environment with an environment variable. "
        " Lambda function is updated to perform 'decrement' action also. "
        TRY.
            lo_lmd->updatefunctioncode(
                  iv_functionname = iv_function_name
                  iv_zipfile = io_updated_zip_file ).
            WAIT UP TO 10 SECONDS.            " Make sure that the update is completed. "
            MESSAGE 'Lambda function code updated.' TYPE 'I'.
          CATCH /aws1/cx_lmdcodestorageexcdex.
            MESSAGE 'Maximum total code size per account exceeded.' TYPE 'E'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'E'.
        ENDTRY.

        TRY.
            DATA lt_variables TYPE /aws1/cl_lmdenvironmentvaria00=>tt_environmentvariables.
            DATA ls_variable LIKE LINE OF lt_variables.
            ls_variable-key = 'LOG_LEVEL'.
            ls_variable-value = NEW /aws1/cl_lmdenvironmentvaria00( iv_value = 'info' ).
            INSERT ls_variable INTO TABLE lt_variables.

            lo_lmd->updatefunctionconfiguration(
                  iv_functionname = iv_function_name
                  io_environment = NEW /aws1/cl_lmdenvironment( it_variables = lt_variables ) ).
            WAIT UP TO 10 SECONDS.            " Make sure that the update is completed. "
            MESSAGE 'Lambda function configuration/settings updated.' TYPE 'I'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourceconflictex.
            MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'E'.
        ENDTRY.

        "Invoke the function with new parameters and get results. Display the execution log that's returned from the invocation."
        TRY.
            lv_json = /aws1/cl_rt_util=>string_to_xstring(
              `{`  &&
                `"action": "decrement",`  &&
                `"number": 10` &&
              `}` ).
            DATA(lo_updated_invoke_output) = lo_lmd->invoke(
                       iv_functionname = iv_function_name
                       iv_payload = lv_json ).
            ov_updated_invoke_payload = lo_updated_invoke_output->get_payload( ).           " ov_updated_invoke_payload is returned for testing purposes. "
            lo_writer_json = cl_sxml_string_writer=>create( type = if_sxml=>co_xt_json ).
            CALL TRANSFORMATION id SOURCE XML ov_updated_invoke_payload RESULT XML lo_writer_json.
            lv_result = cl_abap_codepage=>convert_from( lo_writer_json->get_output( ) ).
            MESSAGE 'Lambda function invoked.' TYPE 'I'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdinvrequestcontex.
            MESSAGE 'Unable to parse request body as JSON.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'E'.
          CATCH /aws1/cx_lmdunsuppedmediatyp00.
            MESSAGE 'Invoke request body does not have JSON as its content type.' TYPE 'E'.
        ENDTRY.

        " List the functions for your account. "
        TRY.
            DATA(lo_list_output) = lo_lmd->listfunctions( ).
            DATA(lt_functions) = lo_list_output->get_functions( ).
            MESSAGE 'Retrieved list of Lambda functions.' TYPE 'I'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
        ENDTRY.

        " Delete the Lambda function. "
        TRY.
            lo_lmd->deletefunction( iv_functionname = iv_function_name ).
            MESSAGE 'Lambda function deleted.' TYPE 'I'.
          CATCH /aws1/cx_lmdinvparamvalueex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_lmdresourcenotfoundex.
            MESSAGE 'The requested resource does not exist.' TYPE 'W'.
        ENDTRY.

        " Detach role policy. "
        TRY.
            lo_iam->detachrolepolicy(
                iv_rolename  = iv_role_name
                iv_policyarn = 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole' ).
            MESSAGE 'Detached policy from the IAM role.' TYPE 'I'.
          CATCH /aws1/cx_iaminvalidinputex.
            MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
          CATCH /aws1/cx_iamnosuchentityex.
            MESSAGE 'The requested resource entity does not exist.' TYPE 'W'.
          CATCH /aws1/cx_iamplynotattachableex.
            MESSAGE 'Service role policies can only be attached to the service-linked role for their service.' TYPE 'E'.
          CATCH /aws1/cx_iamunmodableentityex.
            MESSAGE 'Service that depends on the service-linked role is not modifiable.' TYPE 'E'.
        ENDTRY.

        " Delete the IAM role. "
        TRY.
            lo_iam->deleterole( iv_rolename = iv_role_name ).
            MESSAGE 'IAM role deleted.' TYPE 'I'.
          CATCH /aws1/cx_iamnosuchentityex.
            MESSAGE 'The requested resource entity does not exist.' TYPE 'W'.
          CATCH /aws1/cx_iamunmodableentityex.
            MESSAGE 'Service that depends on the service-linked role is not modifiable.' TYPE 'E'.
        ENDTRY.

      CATCH /aws1/cx_rt_service_generic INTO lo_exception.
        DATA(lv_error) = lo_exception->get_longtext( ).
        MESSAGE lv_error TYPE 'E'.
    ENDTRY.
```
+ For API details, see the following topics in *AWS SDK for SAP ABAP API reference*.
  + [CreateFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [DeleteFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [GetFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [Invoke](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [ListFunctions](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [UpdateFunctionCode](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)
  + [UpdateFunctionConfiguration](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html)

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 
Define the first Lambda function, which simply increments the specified value.  

```
// swift-tools-version: 5.9
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//
// The swift-tools-version declares the minimum version of Swift required to
// build this package.

import PackageDescription

let package = Package(
    name: "increment",
    // Let Xcode know the minimum Apple platforms supported.
    platforms: [
        .macOS(.v13)
    ],
    dependencies: [
        // Dependencies declare other packages that this package depends on.
        .package(
            url: "https://github.com/swift-server/swift-aws-lambda-runtime.git",
            branch: "main"),
    ],
    targets: [
        // Targets are the basic building blocks of a package, defining a module or a test suite.
        // Targets can depend on other targets in this package and products
        // from dependencies.
        .executableTarget(
            name: "increment",
            dependencies: [
                .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
            ],
            path: "Sources"
        )
    ]
)

import Foundation
import AWSLambdaRuntime

/// Represents the contents of the requests being received from the client.
/// This structure must be `Decodable` to indicate that its initializer
/// converts an external representation into this type.
struct Request: Decodable, Sendable {
    /// The action to perform.
    let action: String
    /// The number to act upon.
    let number: Int
}

/// The contents of the response sent back to the client. This must be
/// `Encodable`.
struct Response: Encodable, Sendable {
    /// The resulting value after performing the action.
    let answer: Int?
}


/// The Lambda function body.
///
/// - Parameters:
///   - event: The `Request` describing the request made by the
///     client.
///   - context: A `LambdaContext` describing the context in
///     which the lambda function is running.
///
/// - Returns: A `Response` object that will be encoded to JSON and sent
///   to the client by the Lambda runtime.
let incrementLambdaRuntime = LambdaRuntime {
        (event: Request, context: LambdaContext) -> Response in
    let action = event.action
    var answer: Int?

    if action != "increment" {
        context.logger.error("Unrecognized operation: \"\(action)\". The only supported action is \"increment\".")
    } else {
        answer = event.number + 1
        context.logger.info("The calculated answer is \(answer!).")
    }

    let response = Response(answer: answer)
    return response
}

// Run the Lambda runtime code.

try await incrementLambdaRuntime.run()
```
Define the second Lambda function, which performs an arithmetic operation on two numbers.  

```
// swift-tools-version: 5.9
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//
// The swift-tools-version declares the minimum version of Swift required to
// build this package.

import PackageDescription

let package = Package(
    name: "calculator",
    // Let Xcode know the minimum Apple platforms supported.
    platforms: [
        .macOS(.v13)
    ],
    dependencies: [
        // Dependencies declare other packages that this package depends on.
        .package(
            url: "https://github.com/swift-server/swift-aws-lambda-runtime.git",
            branch: "main"),
    ],
    targets: [
        // Targets are the basic building blocks of a package, defining a module or a test suite.
        // Targets can depend on other targets in this package and products
        // from dependencies.
        .executableTarget(
            name: "calculator",
            dependencies: [
                .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
            ],
            path: "Sources"
        )
    ]
)

import Foundation
import AWSLambdaRuntime

/// Represents the contents of the requests being received from the client.
/// This structure must be `Decodable` to indicate that its initializer
/// converts an external representation into this type.
struct Request: Decodable, Sendable {
    /// The action to perform.
    let action: String
    /// The first number to act upon.
    let x: Int
    /// The second number to act upon.
    let y: Int
}

/// A dictionary mapping operation names to closures that perform that
/// operation and return the result.
let actions = [
    "plus": { (x: Int, y: Int) -> Int in
        return x + y
    },
    "minus": { (x: Int, y: Int) -> Int in
        return x - y
    },
    "times": { (x: Int, y: Int) -> Int in
        return x * y
    },
    "divided-by": { (x: Int, y: Int) -> Int in
        return x / y
    }
]

/// The contents of the response sent back to the client. This must be
/// `Encodable`.
struct Response: Encodable, Sendable {
    /// The resulting value after performing the action.
    let answer: Int?
}


/// The Lambda function's entry point. Called by the Lambda runtime.
///
/// - Parameters:
///   - event: The `Request` describing the request made by the
///     client.
///   - context: A `LambdaContext` describing the context in
///     which the lambda function is running.
///
/// - Returns: A `Response` object that will be encoded to JSON and sent
///   to the client by the Lambda runtime.
let calculatorLambdaRuntime = LambdaRuntime {
        (_ event: Request, context: LambdaContext) -> Response in
    let action = event.action
    var answer: Int?
    var actionFunc: ((Int, Int) -> Int)?

    // Get the closure to run to perform the calculation.

    actionFunc = await actions[action]

    guard let actionFunc else {
        context.logger.error("Unrecognized operation '\(action)\'")
        return Response(answer: nil)
    }

    // Perform the calculation and return the answer.

    answer = actionFunc(event.x, event.y)

    guard let answer else {
        context.logger.error("Error computing \(event.x) \(action) \(event.y)")
    }
    context.logger.info("\(event.x) \(action) \(event.y) = \(answer)")

    return Response(answer: answer)
}

try await calculatorLambdaRuntime.run()
```
Define the main program that will invoke the two Lambda functions.  

```
// swift-tools-version: 5.9
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
//
// The swift-tools-version declares the minimum version of Swift required to
// build this package.

import PackageDescription

let package = Package(
    name: "lambda-basics",
    // Let Xcode know the minimum Apple platforms supported.
    platforms: [
        .macOS(.v13)
    ],
    dependencies: [
        // Dependencies declare other packages that this package depends on.
        .package(
            url: "https://github.com/awslabs/aws-sdk-swift",
            from: "1.0.0"),
        .package(
            url: "https://github.com/apple/swift-argument-parser.git",
            branch: "main"
        )
    ],
    targets: [
        // Targets are the basic building blocks of a package, defining a module or a test suite.
        // Targets can depend on other targets in this package and products
        // from dependencies.
        .executableTarget(
            name: "lambda-basics",
            dependencies: [
                .product(name: "AWSLambda", package: "aws-sdk-swift"),
                .product(name: "AWSIAM", package: "aws-sdk-swift"),
                .product(name: "ArgumentParser", package: "swift-argument-parser")
            ],
            path: "Sources"
        )
    ]
)

//
/// An example demonstrating a variety of important AWS Lambda functions.

import ArgumentParser
import AWSIAM
import SmithyWaitersAPI
import AWSClientRuntime
import AWSLambda
import Foundation

/// Represents the contents of the requests being received from the client.
/// This structure must be `Decodable` to indicate that its initializer
/// converts an external representation into this type.
struct IncrementRequest: Encodable, Decodable, Sendable {
    /// The action to perform.
    let action: String
    /// The number to act upon.
    let number: Int
}

struct Response: Encodable, Decodable, Sendable {
    /// The resulting value after performing the action.
    let answer: Int?
}

struct CalculatorRequest: Encodable, Decodable, Sendable {
    /// The action to perform.
    let action: String
    /// The first number to act upon.
    let x: Int
    /// The second number to act upon.
    let y: Int
}

let exampleName = "SwiftLambdaRoleExample"
let basicsFunctionName = "lambda-basics-function"

/// The ARN of the standard IAM policy for execution of Lambda functions.
let policyARN = "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"

struct ExampleCommand: ParsableCommand {
    // -MARK: Command arguments
    @Option(help: "Name of the IAM Role to use for the Lambda functions")
    var role = exampleName
    @Option(help: "Zip archive containing the 'increment' lambda function")
    var incpath: String
    @Option(help: "Zip archive containing the 'calculator' lambda function")
    var calcpath: String
    @Option(help: "Name of the Amazon S3 Region to use (default: us-east-1)")
    var region = "us-east-1"

    static var configuration = CommandConfiguration(
        commandName: "lambda-basics",
        abstract: """
        This example demonstrates several common operations using AWS Lambda.
        """,
        discussion: """
        """
    )

    /// Returns the specified IAM role object.
    /// 
    /// - Parameters:
    ///   - iamClient: `IAMClient` to use when looking for the role.
    ///   - roleName: The name of the role to check.
    ///
    /// - Returns: The `IAMClientTypes.Role` representing the specified role.
    func getRole(iamClient: IAMClient, roleName: String) async throws
                 -> IAMClientTypes.Role {
        do {
            let roleOutput = try await iamClient.getRole(
                input: GetRoleInput(
                    roleName: roleName
                )
            )

            guard let role = roleOutput.role else {
                throw ExampleError.roleNotFound
            }
            return role
        } catch {
            throw ExampleError.roleNotFound
        }
    }

    /// Create the AWS IAM role that will be used to access AWS Lambda.
    /// 
    /// - Parameters:
    ///   - iamClient: The AWS `IAMClient` to use.
    ///   - roleName: The name of the AWS IAM role to use for Lambda.
    ///
    /// - Throws: `ExampleError.roleCreateError`
    ///
    /// - Returns: The `IAMClientTypes.Role` struct that describes the new role.
    func createRoleForLambda(iamClient: IAMClient, roleName: String) async throws -> IAMClientTypes.Role {
        let output = try await iamClient.createRole(
            input: CreateRoleInput(
                assumeRolePolicyDocument:
                """
                {
                    "Version":"2012-10-17",		 	 	 
                    "Statement": [
                        {
                            "Effect": "Allow",
                            "Principal": {"Service": "lambda.amazonaws.com"},
                            "Action": "sts:AssumeRole"
                        }
                    ]
                }
                """,
                roleName: roleName
            )
        )

        guard let role = output.role else {
            throw ExampleError.roleCreateError
        }

        // Wait for the role to be ready for use.

        _ = try await iamClient.waitUntilRoleExists(
            options: WaiterOptions(
                maxWaitTime: 20,
                minDelay: 0.5,
                maxDelay: 2
            ),
            input: GetRoleInput(roleName: roleName)
        )

        return role
    }

    /// Detect whether or not the AWS Lambda function with the specified name
    /// exists, by requesting its function information.
    ///
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - name: The name of the AWS Lambda function to find.
    ///
    /// - Returns: `true` if the Lambda function exists. Otherwise `false`.
    func doesLambdaFunctionExist(lambdaClient: LambdaClient, name: String) async -> Bool {
        do {
            _ = try await lambdaClient.getFunction(
                input: GetFunctionInput(functionName: name)
            )
        } catch {
            return false
        }

        return true
    }

    /// Create the specified AWS Lambda function.
    /// 
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - functionName: The name of the AWS Lambda function to create.
    ///   - roleArn: The ARN of the role to apply to the function.
    ///   - path: The path of the Zip archive containing the function.
    /// 
    /// - Returns: `true` if the AWS Lambda was successfully created; `false`
    ///   if it wasn't.
    func createFunction(lambdaClient: LambdaClient, functionName: String,
                                roleArn: String?, path: String) async throws -> Bool {
        do {
            // Read the Zip archive containing the AWS Lambda function.

            let zipUrl = URL(fileURLWithPath: path)
            let zipData = try Data(contentsOf: zipUrl)

            // Create the AWS Lambda function that runs the specified code,
            // using the name given on the command line. The Lambda function
            // will run using the Amazon Linux 2 runtime.

            _ = try await lambdaClient.createFunction(
                input: CreateFunctionInput(
                    code: LambdaClientTypes.FunctionCode(zipFile: zipData),
                    functionName: functionName,
                    handler: "handle",
                    role: roleArn,
                    runtime: .providedal2
                )
            )
        } catch {
            print("*** Error creating Lambda function:")
            dump(error)
            return false
        }

        // Wait for a while to be sure the function is done being created.

        let output = try await lambdaClient.waitUntilFunctionActiveV2(
            options: WaiterOptions(
                maxWaitTime: 20,
                minDelay: 0.5,
                maxDelay: 2
            ),
            input: GetFunctionInput(functionName: functionName)
        )

        switch output.result {
            case .success:
                return true
            case .failure:
                return false
        }
    }

    /// Update the AWS Lambda function with new code to run when the function
    /// is invoked.
    /// 
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - functionName: The name of the AWS Lambda function to update.
    ///   - path: The pathname of the Zip file containing the packaged Lambda
    ///     function.
    /// - Throws: `ExampleError.zipFileReadError`
    /// - Returns: `true` if the function's code is updated successfully.
    ///   Otherwise, returns `false`.
    func updateFunctionCode(lambdaClient: LambdaClient, functionName: String,
                            path: String) async throws -> Bool {
        let zipUrl = URL(fileURLWithPath: path)
        let zipData: Data

        // Read the function's Zip file.

        do {
            zipData = try Data(contentsOf: zipUrl)
        } catch {
            throw ExampleError.zipFileReadError
        }

        // Update the function's code and wait for the updated version to be
        // ready for use.

        do {
            _ = try await lambdaClient.updateFunctionCode(
                input: UpdateFunctionCodeInput(
                    functionName: functionName,
                    zipFile: zipData
                )
            )
        } catch {
            return false
        }

        let output = try await lambdaClient.waitUntilFunctionUpdatedV2(
            options: WaiterOptions(
                maxWaitTime: 20,
                minDelay: 0.5,
                maxDelay: 2
            ),
            input: GetFunctionInput(
                functionName: functionName
            )
        )

        switch output.result {
            case .success:
                return true
            case .failure:
                return false
        }
    }

    /// Tell the server-side component to log debug output by setting its
    /// environment's `LOG_LEVEL` to `DEBUG`.
    ///
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - functionName: The name of the AWS Lambda function to enable debug
    ///     logging for.
    ///
    /// - Throws: `ExampleError.environmentResponseMissingError`,
    ///   `ExampleError.updateFunctionConfigurationError`,
    ///   `ExampleError.environmentVariablesMissingError`,
    ///   `ExampleError.logLevelIncorrectError`,
    ///   `ExampleError.updateFunctionConfigurationError`
    func enableDebugLogging(lambdaClient: LambdaClient, functionName: String) async throws {
        let envVariables = [
            "LOG_LEVEL": "DEBUG"
        ]
        let environment = LambdaClientTypes.Environment(variables: envVariables)

        do {
            let output = try await lambdaClient.updateFunctionConfiguration(
                input: UpdateFunctionConfigurationInput(
                    environment: environment,
                    functionName: functionName
                )
            )

            guard let response = output.environment else {
                throw ExampleError.environmentResponseMissingError
            }

            if response.error != nil {
                throw ExampleError.updateFunctionConfigurationError
            }

            guard let retVariables = response.variables else {
                throw ExampleError.environmentVariablesMissingError
            }

            for envVar in retVariables {
                if envVar.key == "LOG_LEVEL" && envVar.value != "DEBUG" {
                    print("*** Log level is not set to DEBUG!")
                    throw ExampleError.logLevelIncorrectError
                }
            }
        } catch {
            throw ExampleError.updateFunctionConfigurationError
        }
    }

    /// Returns an array containing the names of all AWS Lambda functions
    /// available to the user.
    ///
    /// - Parameter lambdaClient: The `IAMClient` to use.
    ///
    /// - Throws: `ExampleError.listFunctionsError`
    ///
    /// - Returns: An array of lambda function name strings.
    func getFunctionNames(lambdaClient: LambdaClient) async throws -> [String] {
        let pages = lambdaClient.listFunctionsPaginated(
            input: ListFunctionsInput()
        )

        var functionNames: [String] = []

        for try await page in pages {
            guard let functions = page.functions else {
                throw ExampleError.listFunctionsError
            }

            for function in functions {
                functionNames.append(function.functionName ?? "<unknown>")
            }
        }

        return functionNames
    }

    /// Invoke the Lambda function to increment a value.
    /// 
    /// - Parameters:
    ///   - lambdaClient: The `IAMClient` to use.
    ///   - number: The number to increment.
    ///
    /// - Throws: `ExampleError.noAnswerReceived`, `ExampleError.invokeError`
    ///
    /// - Returns: An integer number containing the incremented value.
    func invokeIncrement(lambdaClient: LambdaClient, number: Int) async throws -> Int {
        do {
            let incRequest = IncrementRequest(action: "increment", number: number)
            let incData = try! JSONEncoder().encode(incRequest)

            // Invoke the lambda function.

            let invokeOutput = try await lambdaClient.invoke(
                input: InvokeInput(
                    functionName: "lambda-basics-function",
                    payload: incData
                )
            )

            let response = try! JSONDecoder().decode(Response.self, from:invokeOutput.payload!)

            guard let answer = response.answer else {
                throw ExampleError.noAnswerReceived
            }
            return answer

        } catch {
            throw ExampleError.invokeError
        }
    }

    /// Invoke the calculator Lambda function.
    /// 
    /// - Parameters:
    ///   - lambdaClient: The `IAMClient` to use.
    ///   - action: Which arithmetic operation to perform: "plus", "minus",
    ///     "times", or "divided-by".
    ///   - x: The first number to use in the computation.
    ///   - y: The second number to use in the computation.
    ///
    /// - Throws: `ExampleError.noAnswerReceived`, `ExampleError.invokeError`
    ///
    /// - Returns: The computed answer as an `Int`.
    func invokeCalculator(lambdaClient: LambdaClient, action: String, x: Int, y: Int) async throws -> Int {
        do {
            let calcRequest = CalculatorRequest(action: action, x: x, y: y)
            let calcData = try! JSONEncoder().encode(calcRequest)

            // Invoke the lambda function.

            let invokeOutput = try await lambdaClient.invoke(
                input: InvokeInput(
                    functionName: "lambda-basics-function",
                    payload: calcData
                )
            )

            let response = try! JSONDecoder().decode(Response.self, from:invokeOutput.payload!)
            
            guard let answer = response.answer else {
                throw ExampleError.noAnswerReceived
            }
            return answer

        } catch {
            throw ExampleError.invokeError
        }

    }

    /// Perform the example's tasks.
    func basics() async throws {
        let iamClient = try await IAMClient(
            config: IAMClient.IAMClientConfiguration(region: region)
        )

        let lambdaClient = try await LambdaClient(
            config: LambdaClient.LambdaClientConfiguration(region: region)
        )

        /// The IAM role to use for the example.
        var iamRole: IAMClientTypes.Role
        
        // Look for the specified role. If it already exists, use it. If not,
        // create it and attach the desired policy to it.

        do {
            iamRole = try await getRole(iamClient: iamClient, roleName: role)
        } catch ExampleError.roleNotFound {
            // The role wasn't found, so create it and attach the needed
            // policy.
            
            iamRole = try await createRoleForLambda(iamClient: iamClient, roleName: role)

            do {
                _ = try await iamClient.attachRolePolicy(
                    input: AttachRolePolicyInput(policyArn: policyARN, roleName: role)
                )
            } catch {
                throw ExampleError.policyError
            }
        }

        // Give the policy time to attach to the role.

        sleep(5)

        // Look to see if the function already exists. If it does, throw an
        // error.

        if await doesLambdaFunctionExist(lambdaClient: lambdaClient, name: basicsFunctionName) {
            throw ExampleError.functionAlreadyExists
        }

        // Create, then invoke, the "increment" version of the calculator
        // function.

        print("Creating the increment Lambda function...")
        if try await createFunction(lambdaClient: lambdaClient, functionName: basicsFunctionName, 
                                  roleArn: iamRole.arn, path: incpath) {
            print("Running increment function calls...")
            for number in 0...4 {
                do {
                    let answer = try await invokeIncrement(lambdaClient: lambdaClient, number: number)
                    print("Increment \(number) = \(answer)")
                } catch {
                    print("Error incrementing \(number): ", error.localizedDescription)
                }
            }
        } else {
            print("*** Failed to create the increment function.")
        }
        
        // Enable debug logging.

        print("\nEnabling debug logging...")
        try await enableDebugLogging(lambdaClient: lambdaClient, functionName: basicsFunctionName)

        // Change it to a basic arithmetic calculator. Then invoke it a few
        // times.

        print("\nReplacing the Lambda function with a calculator...")

        if try await updateFunctionCode(lambdaClient: lambdaClient, functionName: basicsFunctionName, 
                                    path: calcpath) {
            print("Running calculator function calls...")
            for x in [6, 10] {
                for y in [2, 4] {
                    for action in ["plus", "minus", "times", "divided-by"] {
                        do {
                            let answer = try await invokeCalculator(lambdaClient: lambdaClient, action: action, x: x, y: y)
                            print("\(x) \(action) \(y) = \(answer)")
                        } catch {
                            print("Error calculating \(x) \(action) \(y): ", error.localizedDescription)
                        }
                    }
                }
            }
        }

        // List all lambda functions.

        let functionNames = try await getFunctionNames(lambdaClient: lambdaClient)

        if functionNames.count > 0 {
            print("\nAWS Lambda functions available on your account:")
            for name in functionNames {
                print("  \(name)")
            }
        }

        // Delete the lambda function.

        print("Deleting lambda function...")
        
        do {
            _ = try await lambdaClient.deleteFunction(
                input: DeleteFunctionInput(
                    functionName: "lambda-basics-function"
                )
            )
        } catch {
            print("Error: Unable to delete the function.")
        }
        
        // Detach the role from the policy, then delete the role.

        print("Deleting the AWS IAM role...")

        do {
            _ = try await iamClient.detachRolePolicy(
                input: DetachRolePolicyInput(
                    policyArn: policyARN,
                    roleName: role
                )
            )
            _ = try await iamClient.deleteRole(
                input: DeleteRoleInput(
                    roleName: role
                )
            )
        } catch {
            throw ExampleError.deleteRoleError
        }
    }
}

// -MARK: - Entry point

/// The program's asynchronous entry point.
@main
struct Main {
    static func main() async {
        let args = Array(CommandLine.arguments.dropFirst())

        do {
            let command = try ExampleCommand.parse(args)
            try await command.basics()
        } catch {
            ExampleCommand.exit(withError: error)
        }
    }    
}


/// Errors thrown by the example's functions.
enum ExampleError: Error {
    /// An AWS Lambda function with the specified name already exists.
    case functionAlreadyExists
    /// The specified role doesn't exist.
    case roleNotFound
    /// Unable to create the role.
    case roleCreateError
    /// Unable to delete the role.
    case deleteRoleError
    /// Unable to attach a policy to the role.
    case policyError
    /// Unable to get the executable directory.
    case executableNotFound
    /// An error occurred creating a lambda function.
    case createLambdaError
    /// An error occurred invoking the lambda function.
    case invokeError
    /// No answer received from the invocation.
    case noAnswerReceived
    /// Unable to list the AWS Lambda functions.
    case listFunctionsError
    /// Unable to update the AWS Lambda function.
    case updateFunctionError
    /// Unable to update the function configuration.
    case updateFunctionConfigurationError
    /// The environment response is missing after an
    /// UpdateEnvironmentConfiguration attempt.
    case environmentResponseMissingError
    /// The environment variables are missing from the EnvironmentResponse and
    /// no errors occurred.
    case environmentVariablesMissingError
    /// The log level is incorrect after attempting to set it.
    case logLevelIncorrectError
    /// Unable to load the AWS Lambda function's Zip file.
    case zipFileReadError

    var errorDescription: String? {
        switch self {
        case .functionAlreadyExists:
            return "An AWS Lambda function with that name already exists."
        case .roleNotFound:
            return "The specified role doesn't exist."
        case .deleteRoleError:
            return "Unable to delete the AWS IAM role."
        case .roleCreateError:
            return "Unable to create the specified role."
        case .policyError:
            return "An error occurred attaching the policy to the role."
        case .executableNotFound:
            return "Unable to find the executable program directory."
        case .createLambdaError:
            return "An error occurred creating a lambda function."
        case .invokeError:
            return "An error occurred invoking a lambda function."
        case .noAnswerReceived:
            return "No answer received from the lambda function."
        case .listFunctionsError:
            return "Unable to list the AWS Lambda functions."
        case .updateFunctionError:
            return "Unable to update the AWS lambda function."
        case .updateFunctionConfigurationError:
            return "Unable to update the AWS lambda function configuration."
        case .environmentResponseMissingError:
            return "The environment is missing from the response after updating the function configuration."
        case .environmentVariablesMissingError:
            return "While no error occurred, no environment variables were returned following function configuration."
        case .logLevelIncorrectError:
            return "The log level is incorrect after attempting to set it to DEBUG."
        case .zipFileReadError:
            return "Unable to read the AWS Lambda function."
        }
    }
}
```
+ For API details, see the following topics in *AWS SDK for Swift API reference*.
  + [CreateFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/createfunction(input:))
  + [DeleteFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/deletefunction(input:))
  + [GetFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/getfunction(input:))
  + [Invoke](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/invoke(input:))
  + [ListFunctions](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/listfunctions(input:))
  + [UpdateFunctionCode](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/updatefunctioncode(input:))
  + [UpdateFunctionConfiguration](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/updatefunctionconfiguration(input:))

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Actions for Lambda using AWS SDKs
<a name="service_code_examples_actions"></a>

The following code examples demonstrate how to perform individual Lambda actions with AWS SDKs. Each example includes a link to GitHub, where you can find instructions for setting up and running the code. 

These excerpts call the Lambda API and are code excerpts from larger programs that must be run in context. You can see actions in context in [Scenarios for Lambda using AWS SDKs](service_code_examples_scenarios.md). 

 The following examples include only the most commonly used actions. For a complete list, see the [AWS Lambda API Reference](https://docs.aws.amazon.com/lambda/latest/dg/API_Reference.html). 

**Topics**
+ [`CreateAlias`](example_lambda_CreateAlias_section.md)
+ [`CreateFunction`](example_lambda_CreateFunction_section.md)
+ [`DeleteAlias`](example_lambda_DeleteAlias_section.md)
+ [`DeleteFunction`](example_lambda_DeleteFunction_section.md)
+ [`DeleteFunctionConcurrency`](example_lambda_DeleteFunctionConcurrency_section.md)
+ [`DeleteProvisionedConcurrencyConfig`](example_lambda_DeleteProvisionedConcurrencyConfig_section.md)
+ [`GetAccountSettings`](example_lambda_GetAccountSettings_section.md)
+ [`GetAlias`](example_lambda_GetAlias_section.md)
+ [`GetFunction`](example_lambda_GetFunction_section.md)
+ [`GetFunctionConcurrency`](example_lambda_GetFunctionConcurrency_section.md)
+ [`GetFunctionConfiguration`](example_lambda_GetFunctionConfiguration_section.md)
+ [`GetPolicy`](example_lambda_GetPolicy_section.md)
+ [`GetProvisionedConcurrencyConfig`](example_lambda_GetProvisionedConcurrencyConfig_section.md)
+ [`Invoke`](example_lambda_Invoke_section.md)
+ [`ListFunctions`](example_lambda_ListFunctions_section.md)
+ [`ListProvisionedConcurrencyConfigs`](example_lambda_ListProvisionedConcurrencyConfigs_section.md)
+ [`ListTags`](example_lambda_ListTags_section.md)
+ [`ListVersionsByFunction`](example_lambda_ListVersionsByFunction_section.md)
+ [`PublishVersion`](example_lambda_PublishVersion_section.md)
+ [`PutFunctionConcurrency`](example_lambda_PutFunctionConcurrency_section.md)
+ [`PutProvisionedConcurrencyConfig`](example_lambda_PutProvisionedConcurrencyConfig_section.md)
+ [`RemovePermission`](example_lambda_RemovePermission_section.md)
+ [`TagResource`](example_lambda_TagResource_section.md)
+ [`UntagResource`](example_lambda_UntagResource_section.md)
+ [`UpdateAlias`](example_lambda_UpdateAlias_section.md)
+ [`UpdateFunctionCode`](example_lambda_UpdateFunctionCode_section.md)
+ [`UpdateFunctionConfiguration`](example_lambda_UpdateFunctionConfiguration_section.md)

# Use `CreateAlias` with a CLI
<a name="example_lambda_CreateAlias_section"></a>

The following code examples show how to use `CreateAlias`.

------
#### [ CLI ]

**AWS CLI**  
**To create an alias for a Lambda function**  
The following `create-alias` example creates an alias named `LIVE` that points to version 1 of the `my-function` Lambda function.  

```
aws lambda create-alias \
    --function-name my-function \
    --description "alias for live version of function" \
    --function-version 1 \
    --name LIVE
```
Output:  

```
{
    "FunctionVersion": "1",
    "Name": "LIVE",
    "AliasArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:LIVE",
    "RevisionId": "873282ed-4cd3-4dc8-a069-d0c647e470c6",
    "Description": "alias for live version of function"
}
```
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [CreateAlias](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/create-alias.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example creates a New Lambda Alias for specified version and routing configuration to specify the percentage of invocation requests that it receives.**  

```
New-LMAlias -FunctionName "MylambdaFunction123" -RoutingConfig_AdditionalVersionWeight @{Name="1";Value="0.6} -Description "Alias for version 4" -FunctionVersion 4 -Name "PowershellAlias"
```
+  For API details, see [CreateAlias](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example creates a New Lambda Alias for specified version and routing configuration to specify the percentage of invocation requests that it receives.**  

```
New-LMAlias -FunctionName "MylambdaFunction123" -RoutingConfig_AdditionalVersionWeight @{Name="1";Value="0.6} -Description "Alias for version 4" -FunctionVersion 4 -Name "PowershellAlias"
```
+  For API details, see [CreateAlias](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `CreateFunction` with an AWS SDK or CLI
<a name="example_lambda_CreateFunction_section"></a>

The following code examples show how to use `CreateFunction`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 
+  [Create a REST API with Lambda proxy integration](example_api_gateway_GettingStarted_087_section.md) 
+  [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md) 
+  [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md) 
+  [Using property variables in CloudWatch dashboards to monitor multiple Lambda functions](example_iam_GettingStarted_032_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Creates a new Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the function.</param>
    /// <param name="s3Bucket">The Amazon Simple Storage Service (Amazon S3)
    /// bucket where the zip file containing the code is located.</param>
    /// <param name="s3Key">The Amazon S3 key of the zip file.</param>
    /// <param name="role">The Amazon Resource Name (ARN) of a role with the
    /// appropriate Lambda permissions.</param>
    /// <param name="handler">The name of the handler function.</param>
    /// <returns>The Amazon Resource Name (ARN) of the newly created
    /// Lambda function.</returns>
    public async Task<string> CreateLambdaFunctionAsync(
        string functionName,
        string s3Bucket,
        string s3Key,
        string role,
        string handler)
    {
        // Defines the location for the function code.
        // S3Bucket - The S3 bucket where the file containing
        //            the source code is stored.
        // S3Key    - The name of the file containing the code.
        var functionCode = new FunctionCode
        {
            S3Bucket = s3Bucket,
            S3Key = s3Key,
        };

        var createFunctionRequest = new CreateFunctionRequest
        {
            FunctionName = functionName,
            Description = "Created by the Lambda .NET API",
            Code = functionCode,
            Handler = handler,
            Runtime = Runtime.Dotnet6,
            Role = role,
        };

        var reponse = await _lambdaService.CreateFunctionAsync(createFunctionRequest);
        return reponse.FunctionArn;
    }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/CreateFunction) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::CreateFunctionRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetDescription(LAMBDA_DESCRIPTION); // Optional.
#if USE_CPP_LAMBDA_FUNCTION
        request.SetRuntime(Aws::Lambda::Model::Runtime::provided_al2);
        request.SetTimeout(15);
        request.SetMemorySize(128);

        // Assume the AWS Lambda function was built in Docker with same architecture
        // as this code.
#if  defined(__x86_64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::x86_64});
#elif defined(__aarch64__)
        request.SetArchitectures({Aws::Lambda::Model::Architecture::arm64});
#else
#error "Unimplemented architecture"
#endif // defined(architecture)
#else
        request.SetRuntime(Aws::Lambda::Model::Runtime::python3_9);
#endif
        request.SetRole(roleArn);
        request.SetHandler(LAMBDA_HANDLER_NAME);
        request.SetPublish(true);
        Aws::Lambda::Model::FunctionCode code;
        std::ifstream ifstream(INCREMENT_LAMBDA_CODE.c_str(),
                               std::ios_base::in | std::ios_base::binary);
        if (!ifstream.is_open()) {
            std::cerr << "Error opening file " << INCREMENT_LAMBDA_CODE << "." << std::endl;

#if USE_CPP_LAMBDA_FUNCTION
            std::cerr
                    << "The cpp Lambda function must be built following the instructions in the cpp_lambda/README.md file. "
                    << std::endl;
#endif
            deleteIamRole(clientConfig);
            return false;
        }

        Aws::StringStream buffer;
        buffer << ifstream.rdbuf();

        code.SetZipFile(Aws::Utils::ByteBuffer((unsigned char *) buffer.str().c_str(),
                                               buffer.str().length()));
        request.SetCode(code);

        Aws::Lambda::Model::CreateFunctionOutcome outcome = client.CreateFunction(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda function was successfully created. " << seconds
                      << " seconds elapsed." << std::endl;
            break;
        }

        else {
            std::cerr << "Error with CreateFunction. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            deleteIamRole(clientConfig);
            return false;
        }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/CreateFunction) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**To create a Lambda function**  
The following `create-function` example creates a Lambda function named `my-function`.  

```
aws lambda create-function \
    --function-name my-function \
    --runtime nodejs22.x \
    --zip-file fileb://my-function.zip \
    --handler my-function.handler \
    --role arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-tges6bf4
```
Contents of `my-function.zip`:  

```
This file is a deployment package that contains your function code and any dependencies.
```
Output:  

```
{
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "PFn4S+er27qk+UuZSTKEQfNKG/XNn7QJs90mJgq6oH8=",
    "FunctionName": "my-function",
    "CodeSize": 308,
    "RevisionId": "873282ed-4cd3-4dc8-a069-d0c647e470c6",
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
    "Version": "$LATEST",
    "Role": "arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-zgur6bf4",
    "Timeout": 3,
    "LastModified": "2025-10-14T22:26:11.234+0000",
    "Handler": "my-function.handler",
    "Runtime": "nodejs22.x",
    "Description": ""
}
```
For more information, see [Configure Lambda function memory](https://docs.aws.amazon.com/lambda/latest/dg/configuration-memory.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [CreateFunction](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/create-function.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// CreateFunction creates a new Lambda function from code contained in the zipPackage
// buffer. The specified handlerName must match the name of the file and function
// contained in the uploaded code. The role specified by iamRoleArn is assumed by
// Lambda and grants specific permissions.
// When the function already exists, types.StateActive is returned.
// When the function is created, a lambda.FunctionActiveV2Waiter is used to wait until the
// function is active.
func (wrapper FunctionWrapper) CreateFunction(ctx context.Context, functionName string, handlerName string,
	iamRoleArn *string, zipPackage *bytes.Buffer) types.State {
	var state types.State
	_, err := wrapper.LambdaClient.CreateFunction(ctx, &lambda.CreateFunctionInput{
		Code:         &types.FunctionCode{ZipFile: zipPackage.Bytes()},
		FunctionName: aws.String(functionName),
		Role:         iamRoleArn,
		Handler:      aws.String(handlerName),
		Publish:      true,
		Runtime:      types.RuntimePython39,
	})
	if err != nil {
		var resConflict *types.ResourceConflictException
		if errors.As(err, &resConflict) {
			log.Printf("Function %v already exists.\n", functionName)
			state = types.StateActive
		} else {
			log.Panicf("Couldn't create function %v. Here's why: %v\n", functionName, err)
		}
	} else {
		waiter := lambda.NewFunctionActiveV2Waiter(wrapper.LambdaClient)
		funcOutput, err := waiter.WaitForOutput(ctx, &lambda.GetFunctionInput{
			FunctionName: aws.String(functionName)}, 1*time.Minute)
		if err != nil {
			log.Panicf("Couldn't wait for function %v to be active. Here's why: %v\n", functionName, err)
		} else {
			state = funcOutput.Configuration.State
		}
	}
	return state
}
```
+  For API details, see [CreateFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.CreateFunction) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Creates a new Lambda function in AWS using the AWS Lambda Java API.
     *
     * @param awsLambda    the AWS Lambda client used to interact with the AWS Lambda service
     * @param functionName the name of the Lambda function to create
     * @param key          the S3 key of the function code
     * @param bucketName   the name of the S3 bucket containing the function code
     * @param role         the IAM role to assign to the Lambda function
     * @param handler      the fully qualified class name of the function handler
     * @return the Amazon Resource Name (ARN) of the created Lambda function
     */
    public static String createLambdaFunction(LambdaClient awsLambda,
                                              String functionName,
                                              String key,
                                              String bucketName,
                                              String role,
                                              String handler) {

        try {
            LambdaWaiter waiter = awsLambda.waiter();
            FunctionCode code = FunctionCode.builder()
                .s3Key(key)
                .s3Bucket(bucketName)
                .build();

            CreateFunctionRequest functionRequest = CreateFunctionRequest.builder()
                .functionName(functionName)
                .description("Created by the Lambda Java API")
                .code(code)
                .handler(handler)
                .runtime(Runtime.JAVA17)
                .role(role)
                .build();

            // Create a Lambda function using a waiter
            CreateFunctionResponse functionResponse = awsLambda.createFunction(functionRequest);
            GetFunctionRequest getFunctionRequest = GetFunctionRequest.builder()
                .functionName(functionName)
                .build();
            WaiterResponse<GetFunctionResponse> waiterResponse = waiter.waitUntilFunctionExists(getFunctionRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            return functionResponse.functionArn();

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
        return "";
    }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/CreateFunction) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const createFunction = async (funcName, roleArn) => {
  const client = new LambdaClient({});
  const code = await readFile(`${dirname}../functions/${funcName}.zip`);

  const command = new CreateFunctionCommand({
    Code: { ZipFile: code },
    FunctionName: funcName,
    Role: roleArn,
    Architectures: [Architecture.arm64],
    Handler: "index.handler", // Required when sending a .zip file
    PackageType: PackageType.Zip, // Required when sending a .zip file
    Runtime: Runtime.nodejs16x, // Required when sending a .zip file
  });

  return client.send(command);
};
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/CreateFunctionCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/lambda#code-examples). 

```
suspend fun createNewFunction(
    myFunctionName: String,
    s3BucketName: String,
    myS3Key: String,
    myHandler: String,
    myRole: String,
): String? {
    val functionCode =
        FunctionCode {
            s3Bucket = s3BucketName
            s3Key = myS3Key
        }

    val request =
        CreateFunctionRequest {
            functionName = myFunctionName
            code = functionCode
            description = "Created by the Lambda Kotlin API"
            handler = myHandler
            role = myRole
            runtime = Runtime.Java17
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        val functionResponse = awsLambda.createFunction(request)
        awsLambda.waitUntilFunctionActive {
            functionName = myFunctionName
        }
        return functionResponse.functionArn
    }
}
```
+  For API details, see [CreateFunction](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function createFunction($functionName, $role, $bucketName, $handler)
    {
        //This assumes the Lambda function is in an S3 bucket.
        return $this->customWaiter(function () use ($functionName, $role, $bucketName, $handler) {
            return $this->lambdaClient->createFunction([
                'Code' => [
                    'S3Bucket' => $bucketName,
                    'S3Key' => $functionName,
                ],
                'FunctionName' => $functionName,
                'Role' => $role['Arn'],
                'Runtime' => 'python3.9',
                'Handler' => "$handler.lambda_handler",
            ]);
        });
    }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/CreateFunction) in *AWS SDK for PHP API Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example creates a new C\$1 (dotnetcore1.0 runtime) function named MyFunction in AWS Lambda, providing the compiled binaries for the function from a zip file on the local file system (relative or absolute paths may be used). C\$1 Lambda functions specify the handler for the function using the designation AssemblyName::Namespace.ClassName::MethodName. You should replace the assembly name (without .dll suffix), namespace, class name and method name parts of the handler spec appropriately. The new function will have environment variables 'envvar1' and 'envvar2' set up from the provided values.**  

```
Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -ZipFilename .\MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }
```
**Output:**  

```
CodeSha256       : /NgBMd...gq71I=
CodeSize         : 214784
DeadLetterConfig :
Description      : My C# Lambda Function
Environment      : Amazon.Lambda.Model.EnvironmentResponse
FunctionArn      : arn:aws:lambda:us-west-2:123456789012:function:ToUpper
FunctionName     : MyFunction
Handler          : AssemblyName::Namespace.ClassName::MethodName
KMSKeyArn        :
LastModified     : 2016-12-29T23:50:14.207+0000
MemorySize       : 128
Role             : arn:aws:iam::123456789012:role/LambdaFullExecRole
Runtime          : dotnetcore1.0
Timeout          : 3
Version          : $LATEST
VpcConfig        :
```
**Example 2: This example is similar to the previous one except the function binaries are first uploaded to an Amazon S3 bucket (which must be in the same region as the intended Lambda function) and the resulting S3 object is then referenced when creating the function.**  

```
Write-S3Object -BucketName amzn-s3-demo-bucket -Key MyFunctionBinaries.zip -File .\MyFunctionBinaries.zip    
Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -BucketName amzn-s3-demo-bucket `
        -Key MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example creates a new C\$1 (dotnetcore1.0 runtime) function named MyFunction in AWS Lambda, providing the compiled binaries for the function from a zip file on the local file system (relative or absolute paths may be used). C\$1 Lambda functions specify the handler for the function using the designation AssemblyName::Namespace.ClassName::MethodName. You should replace the assembly name (without .dll suffix), namespace, class name and method name parts of the handler spec appropriately. The new function will have environment variables 'envvar1' and 'envvar2' set up from the provided values.**  

```
Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -ZipFilename .\MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }
```
**Output:**  

```
CodeSha256       : /NgBMd...gq71I=
CodeSize         : 214784
DeadLetterConfig :
Description      : My C# Lambda Function
Environment      : Amazon.Lambda.Model.EnvironmentResponse
FunctionArn      : arn:aws:lambda:us-west-2:123456789012:function:ToUpper
FunctionName     : MyFunction
Handler          : AssemblyName::Namespace.ClassName::MethodName
KMSKeyArn        :
LastModified     : 2016-12-29T23:50:14.207+0000
MemorySize       : 128
Role             : arn:aws:iam::123456789012:role/LambdaFullExecRole
Runtime          : dotnetcore1.0
Timeout          : 3
Version          : $LATEST
VpcConfig        :
```
**Example 2: This example is similar to the previous one except the function binaries are first uploaded to an Amazon S3 bucket (which must be in the same region as the intended Lambda function) and the resulting S3 object is then referenced when creating the function.**  

```
Write-S3Object -BucketName amzn-s3-demo-bucket -Key MyFunctionBinaries.zip -File .\MyFunctionBinaries.zip    
Publish-LMFunction -Description "My C# Lambda Function" `
        -FunctionName MyFunction `
        -BucketName amzn-s3-demo-bucket `
        -Key MyFunctionBinaries.zip `
        -Handler "AssemblyName::Namespace.ClassName::MethodName" `
        -Role "arn:aws:iam::123456789012:role/LambdaFullExecRole" `
        -Runtime dotnetcore1.0 `
        -Environment_Variable @{ "envvar1"="value";"envvar2"="value" }
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def create_function(
        self, function_name, handler_name, iam_role, deployment_package
    ):
        """
        Deploys a Lambda function.

        :param function_name: The name of the Lambda function.
        :param handler_name: The fully qualified name of the handler function. This
                             must include the file name and the function name.
        :param iam_role: The IAM role to use for the function.
        :param deployment_package: The deployment package that contains the function
                                   code in .zip format.
        :return: The Amazon Resource Name (ARN) of the newly created function.
        """
        try:
            response = self.lambda_client.create_function(
                FunctionName=function_name,
                Description="AWS Lambda doc example",
                Runtime="python3.9",
                Role=iam_role.arn,
                Handler=handler_name,
                Code={"ZipFile": deployment_package},
                Publish=True,
            )
            function_arn = response["FunctionArn"]
            waiter = self.lambda_client.get_waiter("function_active_v2")
            waiter.wait(FunctionName=function_name)
            logger.info(
                "Created function '%s' with ARN: '%s'.",
                function_name,
                response["FunctionArn"],
            )
        except ClientError:
            logger.error("Couldn't create function %s.", function_name)
            raise
        else:
            return function_arn
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/CreateFunction) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Deploys a Lambda function.
  #
  # @param function_name: The name of the Lambda function.
  # @param handler_name: The fully qualified name of the handler function.
  # @param role_arn: The IAM role to use for the function.
  # @param deployment_package: The deployment package that contains the function code in .zip format.
  # @return: The Amazon Resource Name (ARN) of the newly created function.
  def create_function(function_name, handler_name, role_arn, deployment_package)
    response = @lambda_client.create_function({
                                                role: role_arn.to_s,
                                                function_name: function_name,
                                                handler: handler_name,
                                                runtime: 'ruby2.7',
                                                code: {
                                                  zip_file: deployment_package
                                                },
                                                environment: {
                                                  variables: {
                                                    'LOG_LEVEL' => 'info'
                                                  }
                                                }
                                              })
    @lambda_client.wait_until(:function_active_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
    response
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error creating #{function_name}:\n #{e.message}")
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
  end
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/CreateFunction) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /**
     * Create a function, uploading from a zip file.
     */
    pub async fn create_function(&self, zip_file: PathBuf) -> Result<String, anyhow::Error> {
        let code = self.prepare_function(zip_file, None).await?;

        let key = code.s3_key().unwrap().to_string();

        let role = self.create_role().await.map_err(|e| anyhow!(e))?;

        info!("Created iam role, waiting 15s for it to become active");
        tokio::time::sleep(Duration::from_secs(15)).await;

        info!("Creating lambda function {}", self.lambda_name);
        let _ = self
            .lambda_client
            .create_function()
            .function_name(self.lambda_name.clone())
            .code(code)
            .role(role.arn())
            .runtime(aws_sdk_lambda::types::Runtime::Providedal2)
            .handler("_unused")
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        self.lambda_client
            .publish_version()
            .function_name(self.lambda_name.clone())
            .send()
            .await?;

        Ok(key)
    }

    /**
     * Upload function code from a path to a zip file.
     * The zip file must have an AL2 Linux-compatible binary called `bootstrap`.
     * The easiest way to create such a zip is to use `cargo lambda build --output-format Zip`.
     */
    async fn prepare_function(
        &self,
        zip_file: PathBuf,
        key: Option<String>,
    ) -> Result<FunctionCode, anyhow::Error> {
        let body = ByteStream::from_path(zip_file).await?;

        let key = key.unwrap_or_else(|| format!("{}_code", self.lambda_name));

        info!("Uploading function code to s3://{}/{}", self.bucket, key);
        let _ = self
            .s3_client
            .put_object()
            .bucket(self.bucket.clone())
            .key(key.clone())
            .body(body)
            .send()
            .await?;

        Ok(FunctionCode::builder()
            .s3_bucket(self.bucket.clone())
            .s3_key(key)
            .build())
    }
```
+  For API details, see [CreateFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.create_function) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        lo_lmd->createfunction(
            iv_functionname = iv_function_name
            iv_runtime = `python3.9`
            iv_role = iv_role_arn
            iv_handler = iv_handler
            io_code = io_zip_file
            iv_description = 'AWS Lambda code example' ).
        MESSAGE 'Lambda function created.' TYPE 'I'.
      CATCH /aws1/cx_lmdcodesigningcfgno00.
        MESSAGE 'Code signing configuration does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodestorageexcdex.
        MESSAGE 'Maximum total code size per account exceeded.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodeverification00.
        MESSAGE 'Code signature failed one or more validation checks for signature mismatch or expiration.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidcodesigex.
        MESSAGE 'Code signature failed the integrity check.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [CreateFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

        do {
            // Read the Zip archive containing the AWS Lambda function.

            let zipUrl = URL(fileURLWithPath: path)
            let zipData = try Data(contentsOf: zipUrl)

            // Create the AWS Lambda function that runs the specified code,
            // using the name given on the command line. The Lambda function
            // will run using the Amazon Linux 2 runtime.

            _ = try await lambdaClient.createFunction(
                input: CreateFunctionInput(
                    code: LambdaClientTypes.FunctionCode(zipFile: zipData),
                    functionName: functionName,
                    handler: "handle",
                    role: roleArn,
                    runtime: .providedal2
                )
            )
        } catch {
            print("*** Error creating Lambda function:")
            dump(error)
            return false
        }
```
+  For API details, see [CreateFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/createfunction(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `DeleteAlias` with a CLI
<a name="example_lambda_DeleteAlias_section"></a>

The following code examples show how to use `DeleteAlias`.

------
#### [ CLI ]

**AWS CLI**  
**To delete an alias of a Lambda function**  
The following `delete-alias` example deletes the alias named `LIVE` from the `my-function` Lambda function.  

```
aws lambda delete-alias \
    --function-name my-function \
    --name LIVE
```
This command produces no output.  
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [DeleteAlias](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/delete-alias.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example deletes the Lambda function Alias mentioned in the command.**  

```
Remove-LMAlias -FunctionName "MylambdaFunction123" -Name "NewAlias"
```
+  For API details, see [DeleteAlias](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example deletes the Lambda function Alias mentioned in the command.**  

```
Remove-LMAlias -FunctionName "MylambdaFunction123" -Name "NewAlias"
```
+  For API details, see [DeleteAlias](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `DeleteFunction` with an AWS SDK or CLI
<a name="example_lambda_DeleteFunction_section"></a>

The following code examples show how to use `DeleteFunction`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 
+  [Create a REST API with Lambda proxy integration](example_api_gateway_GettingStarted_087_section.md) 
+  [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md) 
+  [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md) 
+  [Using property variables in CloudWatch dashboards to monitor multiple Lambda functions](example_iam_GettingStarted_032_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Delete an AWS Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to
    /// delete.</param>
    /// <returns>A Boolean value that indicates the success of the action.</returns>
    public async Task<bool> DeleteFunctionAsync(string functionName)
    {
        var request = new DeleteFunctionRequest
        {
            FunctionName = functionName,
        };

        var response = await _lambdaService.DeleteFunctionAsync(request);

        // A return value of NoContent means that the request was processed.
        // In this case, the function was deleted, and the return value
        // is intentionally blank.
        return response.HttpStatusCode == System.Net.HttpStatusCode.NoContent;
    }
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/DeleteFunction) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

    Aws::Lambda::Model::DeleteFunctionRequest request;
    request.SetFunctionName(LAMBDA_NAME);

    Aws::Lambda::Model::DeleteFunctionOutcome outcome = client.DeleteFunction(
            request);

    if (outcome.IsSuccess()) {
        std::cout << "The lambda function was successfully deleted." << std::endl;
    }
    else {
        std::cerr << "Error with Lambda::DeleteFunction. "
                  << outcome.GetError().GetMessage()
                  << std::endl;
    }
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/DeleteFunction) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**Example 1: To delete a Lambda function by function name**  
The following `delete-function` example deletes the Lambda function named `my-function` by specifying the function's name.  

```
aws lambda delete-function \
    --function-name my-function
```
This command produces no output.  
**Example 2: To delete a Lambda function by function ARN**  
The following `delete-function` example deletes the Lambda function named `my-function` by specifying the function's ARN.  

```
aws lambda delete-function \
    --function-name arn:aws:lambda:us-west-2:123456789012:function:my-function
```
This command produces no output.  
**Example 3: To delete a Lambda function by partial function ARN**  
The following `delete-function` example deletes the Lambda function named `my-function` by specifying the function's partial ARN.  

```
aws lambda delete-function \
    --function-name 123456789012:function:my-function
```
This command produces no output.  
For more information, see [AWS Lambda Function Configuration](https://docs.aws.amazon.com/lambda/latest/dg/resource-model.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [DeleteFunction](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/delete-function.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// DeleteFunction deletes the Lambda function specified by functionName.
func (wrapper FunctionWrapper) DeleteFunction(ctx context.Context, functionName string) {
	_, err := wrapper.LambdaClient.DeleteFunction(ctx, &lambda.DeleteFunctionInput{
		FunctionName: aws.String(functionName),
	})
	if err != nil {
		log.Panicf("Couldn't delete function %v. Here's why: %v\n", functionName, err)
	}
}
```
+  For API details, see [DeleteFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.DeleteFunction) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Deletes an AWS Lambda function.
     *
     * @param awsLambda     an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     * @param functionName  the name of the Lambda function to be deleted
     *
     * @throws LambdaException if an error occurs while deleting the Lambda function
     */
    public static void deleteLambdaFunction(LambdaClient awsLambda, String functionName) {
        try {
            DeleteFunctionRequest request = DeleteFunctionRequest.builder()
                .functionName(functionName)
                .build();

            awsLambda.deleteFunction(request);
            System.out.println("The " + functionName + " function was deleted");

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/DeleteFunction) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
/**
 * @param {string} funcName
 */
const deleteFunction = (funcName) => {
  const client = new LambdaClient({});
  const command = new DeleteFunctionCommand({ FunctionName: funcName });
  return client.send(command);
};
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/DeleteFunctionCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/lambda#code-examples). 

```
suspend fun delLambdaFunction(myFunctionName: String) {
    val request =
        DeleteFunctionRequest {
            functionName = myFunctionName
        }

    LambdaClient { region = "us-east-1" }.use { awsLambda ->
        awsLambda.deleteFunction(request)
        println("$myFunctionName was deleted")
    }
}
```
+  For API details, see [DeleteFunction](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function deleteFunction($functionName)
    {
        return $this->lambdaClient->deleteFunction([
            'FunctionName' => $functionName,
        ]);
    }
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/DeleteFunction) in *AWS SDK for PHP API Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example deletes a specific version of a Lambda function**  

```
Remove-LMFunction -FunctionName "MylambdaFunction123" -Qualifier '3'
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example deletes a specific version of a Lambda function**  

```
Remove-LMFunction -FunctionName "MylambdaFunction123" -Qualifier '3'
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def delete_function(self, function_name):
        """
        Deletes a Lambda function.

        :param function_name: The name of the function to delete.
        """
        try:
            self.lambda_client.delete_function(FunctionName=function_name)
        except ClientError:
            logger.exception("Couldn't delete function %s.", function_name)
            raise
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/DeleteFunction) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Deletes a Lambda function.
  # @param function_name: The name of the function to delete.
  def delete_function(function_name)
    print "Deleting function: #{function_name}..."
    @lambda_client.delete_function(
      function_name: function_name
    )
    print 'Done!'.green
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error deleting #{function_name}:\n #{e.message}")
  end
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/DeleteFunction) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** Delete a function and its role, and if possible or necessary, its associated code object and bucket. */
    pub async fn delete_function(
        &self,
        location: Option<String>,
    ) -> (
        Result<DeleteFunctionOutput, anyhow::Error>,
        Result<DeleteRoleOutput, anyhow::Error>,
        Option<Result<DeleteObjectOutput, anyhow::Error>>,
    ) {
        info!("Deleting lambda function {}", self.lambda_name);
        let delete_function = self
            .lambda_client
            .delete_function()
            .function_name(self.lambda_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from);

        info!("Deleting iam role {}", self.role_name);
        let delete_role = self
            .iam_client
            .delete_role()
            .role_name(self.role_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from);

        let delete_object: Option<Result<DeleteObjectOutput, anyhow::Error>> =
            if let Some(location) = location {
                info!("Deleting object {location}");
                Some(
                    self.s3_client
                        .delete_object()
                        .bucket(self.bucket.clone())
                        .key(location)
                        .send()
                        .await
                        .map_err(anyhow::Error::from),
                )
            } else {
                info!(?location, "Skipping delete object");
                None
            };

        (delete_function, delete_role, delete_object)
    }
```
+  For API details, see [DeleteFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.delete_function) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        lo_lmd->deletefunction( iv_functionname = iv_function_name ).
        MESSAGE 'Lambda function deleted.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [DeleteFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

        do {
            _ = try await lambdaClient.deleteFunction(
                input: DeleteFunctionInput(
                    functionName: "lambda-basics-function"
                )
            )
        } catch {
            print("Error: Unable to delete the function.")
        }
```
+  For API details, see [DeleteFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/deletefunction(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `DeleteFunctionConcurrency` with a CLI
<a name="example_lambda_DeleteFunctionConcurrency_section"></a>

The following code examples show how to use `DeleteFunctionConcurrency`.

------
#### [ CLI ]

**AWS CLI**  
**To remove the reserved concurrent execution limit from a function**  
The following `delete-function-concurrency` example deletes the reserved concurrent execution limit from the `my-function` function.  

```
aws lambda delete-function-concurrency \
    --function-name  my-function
```
This command produces no output.  
For more information, see [Reserving Concurrency for a Lambda Function](https://docs.aws.amazon.com/lambda/latest/dg/per-function-concurrency.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [DeleteFunctionConcurrency](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/delete-function-concurrency.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This examples removes the Function Concurrency of the Lambda Function.**  

```
Remove-LMFunctionConcurrency -FunctionName "MylambdaFunction123"
```
+  For API details, see [DeleteFunctionConcurrency](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This examples removes the Function Concurrency of the Lambda Function.**  

```
Remove-LMFunctionConcurrency -FunctionName "MylambdaFunction123"
```
+  For API details, see [DeleteFunctionConcurrency](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `DeleteProvisionedConcurrencyConfig` with a CLI
<a name="example_lambda_DeleteProvisionedConcurrencyConfig_section"></a>

The following code examples show how to use `DeleteProvisionedConcurrencyConfig`.

------
#### [ CLI ]

**AWS CLI**  
**To delete a provisioned concurrency configuration**  
The following `delete-provisioned-concurrency-config` example deletes the provisioned concurrency configuration for the `GREEN` alias of the specified function.  

```
aws lambda delete-provisioned-concurrency-config \
    --function-name my-function \
    --qualifier GREEN
```
+  For API details, see [DeleteProvisionedConcurrencyConfig](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/delete-provisioned-concurrency-config.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example removes the Provisioned Concurrency Configuration for a specific Alias.**  

```
Remove-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -Qualifier "NewAlias1"
```
+  For API details, see [DeleteProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example removes the Provisioned Concurrency Configuration for a specific Alias.**  

```
Remove-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -Qualifier "NewAlias1"
```
+  For API details, see [DeleteProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetAccountSettings` with a CLI
<a name="example_lambda_GetAccountSettings_section"></a>

The following code examples show how to use `GetAccountSettings`.

------
#### [ CLI ]

**AWS CLI**  
**To retrieve details about your account in an AWS Region**  
The following `get-account-settings` example displays the Lambda limits and usage information for your account.  

```
aws lambda get-account-settings
```
Output:  

```
{
    "AccountLimit": {
       "CodeSizeUnzipped": 262144000,
       "UnreservedConcurrentExecutions": 1000,
       "ConcurrentExecutions": 1000,
       "CodeSizeZipped": 52428800,
       "TotalCodeSize": 80530636800
    },
    "AccountUsage": {
       "FunctionCount": 4,
       "TotalCodeSize": 9426
    }
}
```
For more information, see [AWS Lambda Limits](https://docs.aws.amazon.com/lambda/latest/dg/limits.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [GetAccountSettings](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-account-settings.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This sample displays to compare the Account Limit and Account Usage**  

```
Get-LMAccountSetting | Select-Object @{Name="TotalCodeSizeLimit";Expression={$_.AccountLimit.TotalCodeSize}}, @{Name="TotalCodeSizeUsed";Expression={$_.AccountUsage.TotalCodeSize}}
```
**Output:**  

```
TotalCodeSizeLimit TotalCodeSizeUsed
------------------ -----------------
       80530636800          15078795
```
+  For API details, see [GetAccountSettings](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This sample displays to compare the Account Limit and Account Usage**  

```
Get-LMAccountSetting | Select-Object @{Name="TotalCodeSizeLimit";Expression={$_.AccountLimit.TotalCodeSize}}, @{Name="TotalCodeSizeUsed";Expression={$_.AccountUsage.TotalCodeSize}}
```
**Output:**  

```
TotalCodeSizeLimit TotalCodeSizeUsed
------------------ -----------------
       80530636800          15078795
```
+  For API details, see [GetAccountSettings](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetAlias` with a CLI
<a name="example_lambda_GetAlias_section"></a>

The following code examples show how to use `GetAlias`.

------
#### [ CLI ]

**AWS CLI**  
**To retrieve details about a function alias**  
The following `get-alias` example displays details for the alias named `LIVE` on the `my-function` Lambda function.  

```
aws lambda get-alias \
    --function-name my-function \
    --name LIVE
```
Output:  

```
{
    "FunctionVersion": "3",
    "Name": "LIVE",
    "AliasArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:LIVE",
    "RevisionId": "594f41fb-b85f-4c20-95c7-6ca5f2a92c93",
    "Description": "alias for live version of function"
}
```
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [GetAlias](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-alias.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example retrieves the Routing Config weights for a specific Lambda Function Alias.**  

```
Get-LMAlias -FunctionName "MylambdaFunction123" -Name "newlabel1" -Select RoutingConfig
```
**Output:**  

```
AdditionalVersionWeights
------------------------
{[1, 0.6]}
```
+  For API details, see [GetAlias](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example retrieves the Routing Config weights for a specific Lambda Function Alias.**  

```
Get-LMAlias -FunctionName "MylambdaFunction123" -Name "newlabel1" -Select RoutingConfig
```
**Output:**  

```
AdditionalVersionWeights
------------------------
{[1, 0.6]}
```
+  For API details, see [GetAlias](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetFunction` with an AWS SDK or CLI
<a name="example_lambda_GetFunction_section"></a>

The following code examples show how to use `GetFunction`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 
+  [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Gets information about a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function for
    /// which to retrieve information.</param>
    /// <returns>Async Task.</returns>
    public async Task<FunctionConfiguration> GetFunctionAsync(string functionName)
    {
        var functionRequest = new GetFunctionRequest
        {
            FunctionName = functionName,
        };

        var response = await _lambdaService.GetFunctionAsync(functionRequest);
        return response.Configuration;
    }
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/GetFunction) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::GetFunctionRequest request;
        request.SetFunctionName(functionName);

        Aws::Lambda::Model::GetFunctionOutcome outcome = client.GetFunction(request);

        if (outcome.IsSuccess()) {
            std::cout << "Function retrieve.\n" <<
                      outcome.GetResult().GetConfiguration().Jsonize().View().WriteReadable()
                      << std::endl;
        }
        else {
            std::cerr << "Error with Lambda::GetFunction. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/GetFunction) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**To retrieve information about a function**  
The following `get-function` example displays information about the `my-function` function.  

```
aws lambda get-function \
    --function-name  my-function
```
Output:  

```
{
    "Concurrency": {
        "ReservedConcurrentExecutions": 100
    },
    "Code": {
        "RepositoryType": "S3",
        "Location": "https://awslambda-us-west-2-tasks.s3.us-west-2.amazonaws.com/snapshots/123456789012/my-function..."
    },
    "Configuration": {
        "TracingConfig": {
            "Mode": "PassThrough"
        },
        "Version": "$LATEST",
        "CodeSha256": "5tT2qgzYUHoqwR616pZ2dpkn/0J1FrzJmlKidWaaCgk=",
        "FunctionName": "my-function",
        "VpcConfig": {
            "SubnetIds": [],
            "VpcId": "",
            "SecurityGroupIds": []
        },
        "MemorySize": 128,
        "RevisionId": "28f0fb31-5c5c-43d3-8955-03e76c5c1075",
        "CodeSize": 304,
        "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
        "Handler": "index.handler",
        "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
        "Timeout": 3,
        "LastModified": "2025-09-24T18:20:35.054+0000",
        "Runtime": "nodejs22.x",
        "Description": ""
    }
}
```
For more information, see [Configure Lambda function memory](https://docs.aws.amazon.com/lambda/latest/dg/configuration-memory.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [GetFunction](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-function.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// GetFunction gets data about the Lambda function specified by functionName.
func (wrapper FunctionWrapper) GetFunction(ctx context.Context, functionName string) types.State {
	var state types.State
	funcOutput, err := wrapper.LambdaClient.GetFunction(ctx, &lambda.GetFunctionInput{
		FunctionName: aws.String(functionName),
	})
	if err != nil {
		log.Panicf("Couldn't get function %v. Here's why: %v\n", functionName, err)
	} else {
		state = funcOutput.Configuration.State
	}
	return state
}
```
+  For API details, see [GetFunction](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.GetFunction) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Retrieves information about an AWS Lambda function.
     *
     * @param awsLambda    an instance of the {@link LambdaClient} class, which is used to interact with the AWS Lambda service
     * @param functionName the name of the AWS Lambda function to retrieve information about
     */
    public static void getFunction(LambdaClient awsLambda, String functionName) {
        try {
            GetFunctionRequest functionRequest = GetFunctionRequest.builder()
                .functionName(functionName)
                .build();

            GetFunctionResponse response = awsLambda.getFunction(functionRequest);
            System.out.println("The runtime of this Lambda function is " + response.configuration().runtime());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/GetFunction) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const getFunction = (funcName) => {
  const client = new LambdaClient({});
  const command = new GetFunctionCommand({ FunctionName: funcName });
  return client.send(command);
};
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/GetFunctionCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function getFunction($functionName)
    {
        return $this->lambdaClient->getFunction([
            'FunctionName' => $functionName,
        ]);
    }
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/GetFunction) in *AWS SDK for PHP API Reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def get_function(self, function_name):
        """
        Gets data about a Lambda function.

        :param function_name: The name of the function.
        :return: The function data.
        """
        response = None
        try:
            response = self.lambda_client.get_function(FunctionName=function_name)
        except ClientError as err:
            if err.response["Error"]["Code"] == "ResourceNotFoundException":
                logger.info("Function %s does not exist.", function_name)
            else:
                logger.error(
                    "Couldn't get function %s. Here's why: %s: %s",
                    function_name,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        return response
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/GetFunction) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Gets data about a Lambda function.
  #
  # @param function_name: The name of the function.
  # @return response: The function data, or nil if no such function exists.
  def get_function(function_name)
    @lambda_client.get_function(
      {
        function_name: function_name
      }
    )
  rescue Aws::Lambda::Errors::ResourceNotFoundException => e
    @logger.debug("Could not find function: #{function_name}:\n #{e.message}")
    nil
  end
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/GetFunction) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** Get the Lambda function with this Manager's name. */
    pub async fn get_function(&self) -> Result<GetFunctionOutput, anyhow::Error> {
        info!("Getting lambda function");
        self.lambda_client
            .get_function()
            .function_name(self.lambda_name.clone())
            .send()
            .await
            .map_err(anyhow::Error::from)
    }
```
+  For API details, see [GetFunction](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.get_function) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        oo_result = lo_lmd->getfunction( iv_functionname = iv_function_name ).       " oo_result is returned for testing purposes. "
        MESSAGE 'Lambda function information retrieved.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [GetFunction](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

    /// Detect whether or not the AWS Lambda function with the specified name
    /// exists, by requesting its function information.
    ///
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - name: The name of the AWS Lambda function to find.
    ///
    /// - Returns: `true` if the Lambda function exists. Otherwise `false`.
    func doesLambdaFunctionExist(lambdaClient: LambdaClient, name: String) async -> Bool {
        do {
            _ = try await lambdaClient.getFunction(
                input: GetFunctionInput(functionName: name)
            )
        } catch {
            return false
        }

        return true
    }
```
+  For API details, see [GetFunction](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/getfunction(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetFunctionConcurrency` with a CLI
<a name="example_lambda_GetFunctionConcurrency_section"></a>

The following code examples show how to use `GetFunctionConcurrency`.

------
#### [ CLI ]

**AWS CLI**  
**To view the reserved concurrency setting for a function**  
The following `get-function-concurrency` example retrieves the reserved concurrency setting for the specified function.  

```
aws lambda get-function-concurrency \
    --function-name my-function
```
Output:  

```
{
    "ReservedConcurrentExecutions": 250
}
```
+  For API details, see [GetFunctionConcurrency](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-function-concurrency.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This examples gets the Reserved concurrency for the Lambda Function**  

```
Get-LMFunctionConcurrency -FunctionName "MylambdaFunction123" -Select *
```
**Output:**  

```
ReservedConcurrentExecutions
----------------------------
100
```
+  For API details, see [GetFunctionConcurrency](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This examples gets the Reserved concurrency for the Lambda Function**  

```
Get-LMFunctionConcurrency -FunctionName "MylambdaFunction123" -Select *
```
**Output:**  

```
ReservedConcurrentExecutions
----------------------------
100
```
+  For API details, see [GetFunctionConcurrency](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetFunctionConfiguration` with a CLI
<a name="example_lambda_GetFunctionConfiguration_section"></a>

The following code examples show how to use `GetFunctionConfiguration`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example: 
+  [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md) 

------
#### [ CLI ]

**AWS CLI**  
**To retrieve the version-specific settings of a Lambda function**  
The following `get-function-configuration` example displays the settings for version 2 of the `my-function` function.  

```
aws lambda get-function-configuration \
    --function-name  my-function:2
```
Output:  

```
{
    "FunctionName": "my-function",
    "LastModified": "2019-09-26T20:28:40.438+0000",
    "RevisionId": "e52502d4-9320-4688-9cd6-152a6ab7490d",
    "MemorySize": 256,
    "Version": "2",
    "Role": "arn:aws:iam::123456789012:role/service-role/my-function-role-uy3l9qyq",
    "Timeout": 3,
    "Runtime": "nodejs10.x",
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "5tT2qgzYUHaqwR716pZ2dpkn/0J1FrzJmlKidWoaCgk=",
    "Description": "",
    "VpcConfig": {
        "SubnetIds": [],
        "VpcId": "",
        "SecurityGroupIds": []
    },
    "CodeSize": 304,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:2",
    "Handler": "index.handler"
}
```
For more information, see [AWS Lambda Function Configuration](https://docs.aws.amazon.com/lambda/latest/dg/resource-model.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [GetFunctionConfiguration](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-function-configuration.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example returns the version specific configuration of a Lambda Function.**  

```
Get-LMFunctionConfiguration -FunctionName "MylambdaFunction123" -Qualifier "PowershellAlias"
```
**Output:**  

```
CodeSha256                 : uWOW0R7z+f0VyLuUg7+/D08hkMFsq0SF4seuyUZJ/R8=
CodeSize                   : 1426
DeadLetterConfig           : Amazon.Lambda.Model.DeadLetterConfig
Description                : Verson 3 to test Aliases
Environment                : Amazon.Lambda.Model.EnvironmentResponse
FunctionArn                : arn:aws:lambda:us-east-1:123456789012:function:MylambdaFunction123
                             :PowershellAlias
FunctionName               : MylambdaFunction123
Handler                    : lambda_function.launch_instance
KMSKeyArn                  : 
LastModified               : 2019-12-25T09:52:59.872+0000
LastUpdateStatus           : Successful
LastUpdateStatusReason     : 
LastUpdateStatusReasonCode : 
Layers                     : {}
MasterArn                  : 
MemorySize                 : 128
RevisionId                 : 5d7de38b-87f2-4260-8f8a-e87280e10c33
Role                       : arn:aws:iam::123456789012:role/service-role/lambda
Runtime                    : python3.8
State                      : Active
StateReason                : 
StateReasonCode            : 
Timeout                    : 600
TracingConfig              : Amazon.Lambda.Model.TracingConfigResponse
Version                    : 4
VpcConfig                  : Amazon.Lambda.Model.VpcConfigDetail
```
+  For API details, see [GetFunctionConfiguration](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example returns the version specific configuration of a Lambda Function.**  

```
Get-LMFunctionConfiguration -FunctionName "MylambdaFunction123" -Qualifier "PowershellAlias"
```
**Output:**  

```
CodeSha256                 : uWOW0R7z+f0VyLuUg7+/D08hkMFsq0SF4seuyUZJ/R8=
CodeSize                   : 1426
DeadLetterConfig           : Amazon.Lambda.Model.DeadLetterConfig
Description                : Verson 3 to test Aliases
Environment                : Amazon.Lambda.Model.EnvironmentResponse
FunctionArn                : arn:aws:lambda:us-east-1:123456789012:function:MylambdaFunction123
                             :PowershellAlias
FunctionName               : MylambdaFunction123
Handler                    : lambda_function.launch_instance
KMSKeyArn                  : 
LastModified               : 2019-12-25T09:52:59.872+0000
LastUpdateStatus           : Successful
LastUpdateStatusReason     : 
LastUpdateStatusReasonCode : 
Layers                     : {}
MasterArn                  : 
MemorySize                 : 128
RevisionId                 : 5d7de38b-87f2-4260-8f8a-e87280e10c33
Role                       : arn:aws:iam::123456789012:role/service-role/lambda
Runtime                    : python3.8
State                      : Active
StateReason                : 
StateReasonCode            : 
Timeout                    : 600
TracingConfig              : Amazon.Lambda.Model.TracingConfigResponse
Version                    : 4
VpcConfig                  : Amazon.Lambda.Model.VpcConfigDetail
```
+  For API details, see [GetFunctionConfiguration](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetPolicy` with a CLI
<a name="example_lambda_GetPolicy_section"></a>

The following code examples show how to use `GetPolicy`.

------
#### [ CLI ]

**AWS CLI**  
**To retrieve the resource-based IAM policy for a function, version, or alias**  
The following `get-policy` example displays policy information about the `my-function` Lambda function.  

```
aws lambda get-policy \
    --function-name my-function
```
Output:  

```
{
    "Policy": {
        "Version":"2012-10-17",		 	 	 
        "Id":"default",
        "Statement":
        [
            {
                "Sid":"iot-events",
                "Effect":"Allow",
                "Principal": {"Service":"iotevents.amazonaws.com"},
                "Action":"lambda:InvokeFunction",
                "Resource":"arn:aws:lambda:us-west-2:123456789012:function:my-function"
            }
        ]
    },
    "RevisionId": "93017fc9-59cb-41dc-901b-4845ce4bf668"
}
```
For more information, see [Using Resource-based Policies for AWS Lambda](https://docs.aws.amazon.com/lambda/latest/dg/access-control-resource-based.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [GetPolicy](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-policy.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This sample displays the Function policy of the Lambda function**  

```
Get-LMPolicy -FunctionName test -Select Policy
```
**Output:**  

```
{"Version":"2012-10-17",		 	 	 "Id":"default","Statement":[{"Sid":"xxxx","Effect":"Allow","Principal":{"Service":"sns.amazonaws.com"},"Action":"lambda:InvokeFunction","Resource":"arn:aws:lambda:us-east-1:123456789102:function:test"}]}
```
+  For API details, see [GetPolicy](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This sample displays the Function policy of the Lambda function**  

```
Get-LMPolicy -FunctionName test -Select Policy
```
**Output:**  

```
{"Version":"2012-10-17",		 	 	 "Id":"default","Statement":[{"Sid":"xxxx","Effect":"Allow","Principal":{"Service":"sns.amazonaws.com"},"Action":"lambda:InvokeFunction","Resource":"arn:aws:lambda:us-east-1:123456789102:function:test"}]}
```
+  For API details, see [GetPolicy](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `GetProvisionedConcurrencyConfig` with a CLI
<a name="example_lambda_GetProvisionedConcurrencyConfig_section"></a>

The following code examples show how to use `GetProvisionedConcurrencyConfig`.

------
#### [ CLI ]

**AWS CLI**  
**To view a provisioned concurrency configuration**  
The following `get-provisioned-concurrency-config` example displays details for the provisioned concurrency configuration for the `BLUE` alias of the specified function.  

```
aws lambda get-provisioned-concurrency-config \
    --function-name my-function \
    --qualifier BLUE
```
Output:  

```
{
    "RequestedProvisionedConcurrentExecutions": 100,
    "AvailableProvisionedConcurrentExecutions": 100,
    "AllocatedProvisionedConcurrentExecutions": 100,
    "Status": "READY",
    "LastModified": "2019-12-31T20:28:49+0000"
}
```
+  For API details, see [GetProvisionedConcurrencyConfig](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/get-provisioned-concurrency-config.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example gets the provisioned Concurrency Configuration for the specified Alias of the Lambda Function.**  

```
C:\>Get-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -Qualifier "NewAlias1"
```
**Output:**  

```
AllocatedProvisionedConcurrentExecutions : 0
AvailableProvisionedConcurrentExecutions : 0
LastModified                             : 2020-01-15T03:21:26+0000
RequestedProvisionedConcurrentExecutions : 70
Status                                   : IN_PROGRESS
StatusReason                             :
```
+  For API details, see [GetProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example gets the provisioned Concurrency Configuration for the specified Alias of the Lambda Function.**  

```
C:\>Get-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -Qualifier "NewAlias1"
```
**Output:**  

```
AllocatedProvisionedConcurrentExecutions : 0
AvailableProvisionedConcurrentExecutions : 0
LastModified                             : 2020-01-15T03:21:26+0000
RequestedProvisionedConcurrentExecutions : 70
Status                                   : IN_PROGRESS
StatusReason                             :
```
+  For API details, see [GetProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `Invoke` with an AWS SDK or CLI
<a name="example_lambda_Invoke_section"></a>

The following code examples show how to use `Invoke`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 
+  [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md) 
+  [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md) 
+  [Using property variables in CloudWatch dashboards to monitor multiple Lambda functions](example_iam_GettingStarted_032_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Invoke a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to
    /// invoke.</param
    /// <param name="parameters">The parameter values that will be passed to the function.</param>
    /// <returns>A System Threading Task.</returns>
    public async Task<string> InvokeFunctionAsync(
        string functionName,
        string parameters)
    {
        var payload = parameters;
        var request = new InvokeRequest
        {
            FunctionName = functionName,
            Payload = payload,
        };

        var response = await _lambdaService.InvokeAsync(request);
        MemoryStream stream = response.Payload;
        string returnValue = System.Text.Encoding.UTF8.GetString(stream.ToArray());
        return returnValue;
    }
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/Invoke) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::InvokeRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        request.SetLogType(logType);
        std::shared_ptr<Aws::IOStream> payload = Aws::MakeShared<Aws::StringStream>(
                "FunctionTest");
        *payload << jsonPayload.View().WriteReadable();
        request.SetBody(payload);
        request.SetContentType("application/json");
        Aws::Lambda::Model::InvokeOutcome outcome = client.Invoke(request);

        if (outcome.IsSuccess()) {
            invokeResult = std::move(outcome.GetResult());
            result = true;
            break;
        }

        else {
            std::cerr << "Error with Lambda::InvokeRequest. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
            break;
        }
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/Invoke) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**Example 1: To invoke a Lambda function synchronously**  
The following `invoke` example invokes the `my-function` function synchronously. The `cli-binary-format` option is required if you're using AWS CLI version 2. For more information, see [AWS CLI supported global command line options](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-options.html#cli-configure-options-list) in the *AWS Command Line Interface User Guide*.  

```
aws lambda invoke \
    --function-name my-function \
    --cli-binary-format raw-in-base64-out \
    --payload '{ "name": "Bob" }' \
    response.json
```
Output:  

```
{
    "ExecutedVersion": "$LATEST",
    "StatusCode": 200
}
```
For more information, see [Invoke a Lambda function synchronously](https://docs.aws.amazon.com/lambda/latest/dg/invocation-sync.html) in the *AWS Lambda Developer Guide*.  
**Example 2: To invoke a Lambda function asynchronously**  
The following `invoke` example invokes the `my-function` function asynchronously. The `cli-binary-format` option is required if you're using AWS CLI version 2. For more information, see [AWS CLI supported global command line options](https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-options.html#cli-configure-options-list) in the *AWS Command Line Interface User Guide*.  

```
aws lambda invoke \
    --function-name my-function \
    --invocation-type Event \
    --cli-binary-format raw-in-base64-out \
    --payload '{ "name": "Bob" }' \
    response.json
```
Output:  

```
{
    "StatusCode": 202
}
```
For more information, see [Invoking a Lambda function asynchronously](https://docs.aws.amazon.com/lambda/latest/dg/invocation-async.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [Invoke](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/invoke.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// Invoke invokes the Lambda function specified by functionName, passing the parameters
// as a JSON payload. When getLog is true, types.LogTypeTail is specified, which tells
// Lambda to include the last few log lines in the returned result.
func (wrapper FunctionWrapper) Invoke(ctx context.Context, functionName string, parameters any, getLog bool) *lambda.InvokeOutput {
	logType := types.LogTypeNone
	if getLog {
		logType = types.LogTypeTail
	}
	payload, err := json.Marshal(parameters)
	if err != nil {
		log.Panicf("Couldn't marshal parameters to JSON. Here's why %v\n", err)
	}
	invokeOutput, err := wrapper.LambdaClient.Invoke(ctx, &lambda.InvokeInput{
		FunctionName: aws.String(functionName),
		LogType:      logType,
		Payload:      payload,
	})
	if err != nil {
		log.Panicf("Couldn't invoke function %v. Here's why: %v\n", functionName, err)
	}
	return invokeOutput
}
```
+  For API details, see [Invoke](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.Invoke) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Invokes a specific AWS Lambda function.
     *
     * @param awsLambda    an instance of {@link LambdaClient} to interact with the AWS Lambda service
     * @param functionName the name of the AWS Lambda function to be invoked
     */
    public static void invokeFunction(LambdaClient awsLambda, String functionName) {
        InvokeResponse res;
        try {
            // Need a SdkBytes instance for the payload.
            JSONObject jsonObj = new JSONObject();
            jsonObj.put("inputValue", "2000");
            String json = jsonObj.toString();
            SdkBytes payload = SdkBytes.fromUtf8String(json);

            InvokeRequest request = InvokeRequest.builder()
                .functionName(functionName)
                .payload(payload)
                .build();

            res = awsLambda.invoke(request);
            String value = res.payload().asUtf8String();
            System.out.println(value);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/Invoke) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const invoke = async (funcName, payload) => {
  const client = new LambdaClient({});
  const command = new InvokeCommand({
    FunctionName: funcName,
    Payload: JSON.stringify(payload),
    LogType: LogType.Tail,
  });

  const { Payload, LogResult } = await client.send(command);
  const result = Buffer.from(Payload).toString();
  const logs = Buffer.from(LogResult, "base64").toString();
  return { logs, result };
};
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/InvokeCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/lambda#code-examples). 

```
suspend fun invokeFunction(functionNameVal: String) {
    val json = """{"inputValue":"1000"}"""
    val byteArray = json.trimIndent().encodeToByteArray()
    val request =
        InvokeRequest {
            functionName = functionNameVal
            logType = LogType.Tail
            payload = byteArray
        }

    LambdaClient { region = "us-west-2" }.use { awsLambda ->
        val res = awsLambda.invoke(request)
        println("${res.payload?.toString(Charsets.UTF_8)}")
        println("The log result is ${res.logResult}")
    }
}
```
+  For API details, see [Invoke](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function invoke($functionName, $params, $logType = 'None')
    {
        return $this->lambdaClient->invoke([
            'FunctionName' => $functionName,
            'Payload' => json_encode($params),
            'LogType' => $logType,
        ]);
    }
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/Invoke) in *AWS SDK for PHP API Reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def invoke_function(self, function_name, function_params, get_log=False):
        """
        Invokes a Lambda function.

        :param function_name: The name of the function to invoke.
        :param function_params: The parameters of the function as a dict. This dict
                                is serialized to JSON before it is sent to Lambda.
        :param get_log: When true, the last 4 KB of the execution log are included in
                        the response.
        :return: The response from the function invocation.
        """
        try:
            response = self.lambda_client.invoke(
                FunctionName=function_name,
                Payload=json.dumps(function_params),
                LogType="Tail" if get_log else "None",
            )
            logger.info("Invoked function %s.", function_name)
        except ClientError:
            logger.exception("Couldn't invoke function %s.", function_name)
            raise
        return response
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/Invoke) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Invokes a Lambda function.
  # @param function_name [String] The name of the function to invoke.
  # @param payload [nil] Payload containing runtime parameters.
  # @return [Object] The response from the function invocation.
  def invoke_function(function_name, payload = nil)
    params = { function_name: function_name }
    params[:payload] = payload unless payload.nil?
    @lambda_client.invoke(params)
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error executing #{function_name}:\n #{e.message}")
  end
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/Invoke) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** Invoke the lambda function using calculator InvokeArgs. */
    pub async fn invoke(&self, args: InvokeArgs) -> Result<InvokeOutput, anyhow::Error> {
        info!(?args, "Invoking {}", self.lambda_name);
        let payload = serde_json::to_string(&args)?;
        debug!(?payload, "Sending payload");
        self.lambda_client
            .invoke()
            .function_name(self.lambda_name.clone())
            .payload(Blob::new(payload))
            .send()
            .await
            .map_err(anyhow::Error::from)
    }

fn log_invoke_output(invoke: &InvokeOutput, message: &str) {
    if let Some(payload) = invoke.payload().cloned() {
        let payload = String::from_utf8(payload.into_inner());
        info!(?payload, message);
    } else {
        info!("Could not extract payload")
    }
    if let Some(logs) = invoke.log_result() {
        debug!(?logs, "Invoked function logs")
    } else {
        debug!("Invoked function had no logs")
    }
}
```
+  For API details, see [Invoke](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.invoke) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        DATA(lv_json) = /aws1/cl_rt_util=>string_to_xstring(
          `{`  &&
            `"action": "increment",`  &&
            `"number": 10` &&
          `}` ).
        oo_result = lo_lmd->invoke(                  " oo_result is returned for testing purposes. "
                 iv_functionname = iv_function_name
                 iv_payload = lv_json ).
        MESSAGE 'Lambda function invoked.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvrequestcontex.
        MESSAGE 'Unable to parse request body as JSON.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidzipfileex.
        MESSAGE 'The deployment package could not be unzipped.' TYPE 'E'.
      CATCH /aws1/cx_lmdrequesttoolargeex.
        MESSAGE 'Invoke request body JSON input limit was exceeded by the request payload.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
      CATCH /aws1/cx_lmdunsuppedmediatyp00.
        MESSAGE 'Invoke request body does not have JSON as its content type.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [Invoke](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

    /// Invoke the Lambda function to increment a value.
    /// 
    /// - Parameters:
    ///   - lambdaClient: The `IAMClient` to use.
    ///   - number: The number to increment.
    ///
    /// - Throws: `ExampleError.noAnswerReceived`, `ExampleError.invokeError`
    ///
    /// - Returns: An integer number containing the incremented value.
    func invokeIncrement(lambdaClient: LambdaClient, number: Int) async throws -> Int {
        do {
            let incRequest = IncrementRequest(action: "increment", number: number)
            let incData = try! JSONEncoder().encode(incRequest)

            // Invoke the lambda function.

            let invokeOutput = try await lambdaClient.invoke(
                input: InvokeInput(
                    functionName: "lambda-basics-function",
                    payload: incData
                )
            )

            let response = try! JSONDecoder().decode(Response.self, from:invokeOutput.payload!)

            guard let answer = response.answer else {
                throw ExampleError.noAnswerReceived
            }
            return answer

        } catch {
            throw ExampleError.invokeError
        }
    }
```
+  For API details, see [Invoke](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/invoke(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `ListFunctions` with an AWS SDK or CLI
<a name="example_lambda_ListFunctions_section"></a>

The following code examples show how to use `ListFunctions`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 
+  [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Get a list of Lambda functions.
    /// </summary>
    /// <returns>A list of FunctionConfiguration objects.</returns>
    public async Task<List<FunctionConfiguration>> ListFunctionsAsync()
    {
        var functionList = new List<FunctionConfiguration>();

        var functionPaginator =
            _lambdaService.Paginators.ListFunctions(new ListFunctionsRequest());
        await foreach (var function in functionPaginator.Functions)
        {
            functionList.Add(function);
        }

        return functionList;
    }
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

    std::vector<Aws::String> functions;
    Aws::String marker;

    do {
        Aws::Lambda::Model::ListFunctionsRequest request;
        if (!marker.empty()) {
            request.SetMarker(marker);
        }

        Aws::Lambda::Model::ListFunctionsOutcome outcome = client.ListFunctions(
                request);

        if (outcome.IsSuccess()) {
            const Aws::Lambda::Model::ListFunctionsResult &result = outcome.GetResult();
            std::cout << result.GetFunctions().size()
                      << " lambda functions were retrieved." << std::endl;

            for (const Aws::Lambda::Model::FunctionConfiguration &functionConfiguration: result.GetFunctions()) {
                functions.push_back(functionConfiguration.GetFunctionName());
                std::cout << functions.size() << "  "
                          << functionConfiguration.GetDescription() << std::endl;
                std::cout << "   "
                          << Aws::Lambda::Model::RuntimeMapper::GetNameForRuntime(
                                  functionConfiguration.GetRuntime()) << ": "
                          << functionConfiguration.GetHandler()
                          << std::endl;
            }
            marker = result.GetNextMarker();
        }
        else {
            std::cerr << "Error with Lambda::ListFunctions. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    } while (!marker.empty());
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/ListFunctions) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**To retrieve a list of Lambda functions**  
The following `list-functions` example displays a list of all of the functions for the current user.  

```
aws lambda list-functions
```
Output:  

```
{
    "Functions": [
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "dBG9m8SGdmlEjw/JYXlhhvCrAv5TxvXsbL/RMr0fT/I=",
            "FunctionName": "helloworld",
            "MemorySize": 128,
            "RevisionId": "1718e831-badf-4253-9518-d0644210af7b",
            "CodeSize": 294,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:helloworld",
            "Handler": "helloworld.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-zgur6bf4",
            "Timeout": 3,
            "LastModified": "2025-09-23T18:32:33.857+0000",
            "Runtime": "nodejs22.x",
            "Description": ""
        },
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "sU0cJ2/hOZevwV/lTxCuQqK3gDZP3i8gUoqUUVRmY6E=",
            "FunctionName": "my-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 256,
            "RevisionId": "93017fc9-59cb-41dc-901b-4845ce4bf668",
            "CodeSize": 266,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
            "Handler": "index.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
            "Timeout": 3,
            "LastModified": "2025-10-01T16:47:28.490+0000",
            "Runtime": "nodejs22.x",
            "Description": ""
        },
        {
            "Layers": [
                {
                    "CodeSize": 41784542,
                    "Arn": "arn:aws:lambda:us-west-2:420165488524:layer:AWSLambda-Python37-SciPy1x:2"
                },
                {
                    "CodeSize": 4121,
                    "Arn": "arn:aws:lambda:us-west-2:123456789012:layer:pythonLayer:1"
                }
            ],
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "ZQukCqxtkqFgyF2cU41Avj99TKQ/hNihPtDtRcc08mI=",
            "FunctionName": "my-python-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 128,
            "RevisionId": "80b4eabc-acf7-4ea8-919a-e874c213707d",
            "CodeSize": 299,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-python-function",
            "Handler": "lambda_function.lambda_handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/my-python-function-role-z5g7dr6n",
            "Timeout": 3,
            "LastModified": "2025-10-01T19:40:41.643+0000",
            "Runtime": "python3.11",
            "Description": ""
        }
    ]
}
```
For more information, see [Configure Lambda function memory](https://docs.aws.amazon.com/lambda/latest/dg/configuration-memory.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [ListFunctions](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/list-functions.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// ListFunctions lists up to maxItems functions for the account. This function uses a
// lambda.ListFunctionsPaginator to paginate the results.
func (wrapper FunctionWrapper) ListFunctions(ctx context.Context, maxItems int) []types.FunctionConfiguration {
	var functions []types.FunctionConfiguration
	paginator := lambda.NewListFunctionsPaginator(wrapper.LambdaClient, &lambda.ListFunctionsInput{
		MaxItems: aws.Int32(int32(maxItems)),
	})
	for paginator.HasMorePages() && len(functions) < maxItems {
		pageOutput, err := paginator.NextPage(ctx)
		if err != nil {
			log.Panicf("Couldn't list functions for your account. Here's why: %v\n", err)
		}
		functions = append(functions, pageOutput.Functions...)
	}
	return functions
}
```
+  For API details, see [ListFunctions](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.ListFunctions) in *AWS SDK for Go API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const listFunctions = () => {
  const client = new LambdaClient({});
  const command = new ListFunctionsCommand({});

  return client.send(command);
};
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/ListFunctionsCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function listFunctions($maxItems = 50, $marker = null)
    {
        if (is_null($marker)) {
            return $this->lambdaClient->listFunctions([
                'MaxItems' => $maxItems,
            ]);
        }

        return $this->lambdaClient->listFunctions([
            'Marker' => $marker,
            'MaxItems' => $maxItems,
        ]);
    }
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for PHP API Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This sample displays all the Lambda functions with sorted code size**  

```
Get-LMFunctionList | Sort-Object -Property CodeSize | Select-Object FunctionName, RunTime, Timeout, CodeSize
```
**Output:**  

```
FunctionName                                                 Runtime   Timeout CodeSize
------------                                                 -------   ------- --------
test                                                         python2.7       3      243
MylambdaFunction123                                          python3.8     600      659
myfuncpython1                                                python3.8     303      675
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This sample displays all the Lambda functions with sorted code size**  

```
Get-LMFunctionList | Sort-Object -Property CodeSize | Select-Object FunctionName, RunTime, Timeout, CodeSize
```
**Output:**  

```
FunctionName                                                 Runtime   Timeout CodeSize
------------                                                 -------   ------- --------
test                                                         python2.7       3      243
MylambdaFunction123                                          python3.8     600      659
myfuncpython1                                                python3.8     303      675
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def list_functions(self):
        """
        Lists the Lambda functions for the current account.
        """
        try:
            func_paginator = self.lambda_client.get_paginator("list_functions")
            for func_page in func_paginator.paginate():
                for func in func_page["Functions"]:
                    print(func["FunctionName"])
                    desc = func.get("Description")
                    if desc:
                        print(f"\t{desc}")
                    print(f"\t{func['Runtime']}: {func['Handler']}")
        except ClientError as err:
            logger.error(
                "Couldn't list functions. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Lists the Lambda functions for the current account.
  def list_functions
    functions = []
    @lambda_client.list_functions.each do |response|
      response['functions'].each do |function|
        functions.append(function['function_name'])
      end
    end
    functions
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error listing functions:\n #{e.message}")
  end
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** List all Lambda functions in the current Region. */
    pub async fn list_functions(&self) -> Result<ListFunctionsOutput, anyhow::Error> {
        info!("Listing lambda functions");
        self.lambda_client
            .list_functions()
            .send()
            .await
            .map_err(anyhow::Error::from)
    }
```
+  For API details, see [ListFunctions](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.list_functions) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        oo_result = lo_lmd->listfunctions( ).       " oo_result is returned for testing purposes. "
        DATA(lt_functions) = oo_result->get_functions( ).
        MESSAGE 'Retrieved list of Lambda functions.' TYPE 'I'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [ListFunctions](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

    /// Returns an array containing the names of all AWS Lambda functions
    /// available to the user.
    ///
    /// - Parameter lambdaClient: The `IAMClient` to use.
    ///
    /// - Throws: `ExampleError.listFunctionsError`
    ///
    /// - Returns: An array of lambda function name strings.
    func getFunctionNames(lambdaClient: LambdaClient) async throws -> [String] {
        let pages = lambdaClient.listFunctionsPaginated(
            input: ListFunctionsInput()
        )

        var functionNames: [String] = []

        for try await page in pages {
            guard let functions = page.functions else {
                throw ExampleError.listFunctionsError
            }

            for function in functions {
                functionNames.append(function.functionName ?? "<unknown>")
            }
        }

        return functionNames
    }
```
+  For API details, see [ListFunctions](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/listfunctions(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `ListProvisionedConcurrencyConfigs` with a CLI
<a name="example_lambda_ListProvisionedConcurrencyConfigs_section"></a>

The following code examples show how to use `ListProvisionedConcurrencyConfigs`.

------
#### [ CLI ]

**AWS CLI**  
**To get a list of provisioned concurrency configurations**  
The following `list-provisioned-concurrency-configs` example lists the provisioned concurrency configurations for the specified function.  

```
aws lambda list-provisioned-concurrency-configs \
    --function-name my-function
```
Output:  

```
{
    "ProvisionedConcurrencyConfigs": [
        {
            "FunctionArn": "arn:aws:lambda:us-east-2:123456789012:function:my-function:GREEN",
            "RequestedProvisionedConcurrentExecutions": 100,
            "AvailableProvisionedConcurrentExecutions": 100,
            "AllocatedProvisionedConcurrentExecutions": 100,
            "Status": "READY",
            "LastModified": "2019-12-31T20:29:00+0000"
        },
        {
            "FunctionArn": "arn:aws:lambda:us-east-2:123456789012:function:my-function:BLUE",
            "RequestedProvisionedConcurrentExecutions": 100,
            "AvailableProvisionedConcurrentExecutions": 100,
            "AllocatedProvisionedConcurrentExecutions": 100,
            "Status": "READY",
            "LastModified": "2019-12-31T20:28:49+0000"
        }
    ]
}
```
+  For API details, see [ListProvisionedConcurrencyConfigs](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/list-provisioned-concurrency-configs.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example retrieves the list of provisioned concurrency configurations for a Lambda function.**  

```
Get-LMProvisionedConcurrencyConfigList -FunctionName "MylambdaFunction123"
```
+  For API details, see [ListProvisionedConcurrencyConfigs](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example retrieves the list of provisioned concurrency configurations for a Lambda function.**  

```
Get-LMProvisionedConcurrencyConfigList -FunctionName "MylambdaFunction123"
```
+  For API details, see [ListProvisionedConcurrencyConfigs](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `ListTags` with a CLI
<a name="example_lambda_ListTags_section"></a>

The following code examples show how to use `ListTags`.

------
#### [ CLI ]

**AWS CLI**  
**To retrieve the list of tags for a Lambda function**  
The following `list-tags` example displays the tags attached to the `my-function` Lambda function.  

```
aws lambda list-tags \
    --resource arn:aws:lambda:us-west-2:123456789012:function:my-function
```
Output:  

```
{
    "Tags": {
        "Category": "Web Tools",
        "Department": "Sales"
    }
}
```
For more information, see [Tagging Lambda Functions](https://docs.aws.amazon.com/lambda/latest/dg/tagging.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [ListTags](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/list-tags.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: Retrieves the tags and their values currently set on the specified function.**  

```
Get-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction"
```
**Output:**  

```
Key        Value
---        -----
California Sacramento
Oregon     Salem
Washington Olympia
```
+  For API details, see [ListTags](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: Retrieves the tags and their values currently set on the specified function.**  

```
Get-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction"
```
**Output:**  

```
Key        Value
---        -----
California Sacramento
Oregon     Salem
Washington Olympia
```
+  For API details, see [ListTags](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `ListVersionsByFunction` with a CLI
<a name="example_lambda_ListVersionsByFunction_section"></a>

The following code examples show how to use `ListVersionsByFunction`.

------
#### [ CLI ]

**AWS CLI**  
**To retrieve a list of versions of a function**  
The following `list-versions-by-function` example displays the list of versions for the `my-function` Lambda function.  

```
aws lambda list-versions-by-function \
    --function-name my-function
```
Output:  

```
{
    "Versions": [
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "$LATEST",
            "CodeSha256": "sU0cJ2/hOZevwV/lTxCuQqK3gDZP3i8gUoqUUVRmY6E=",
            "FunctionName": "my-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 256,
            "RevisionId": "93017fc9-59cb-41dc-901b-4845ce4bf668",
            "CodeSize": 266,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:$LATEST",
            "Handler": "index.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
            "Timeout": 3,
            "LastModified": "2019-10-01T16:47:28.490+0000",
            "Runtime": "nodejs10.x",
            "Description": ""
        },
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "1",
            "CodeSha256": "5tT2qgzYUHoqwR616pZ2dpkn/0J1FrzJmlKidWaaCgk=",
            "FunctionName": "my-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 256,
            "RevisionId": "949c8914-012e-4795-998c-e467121951b1",
            "CodeSize": 304,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:1",
            "Handler": "index.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
            "Timeout": 3,
            "LastModified": "2019-09-26T20:28:40.438+0000",
            "Runtime": "nodejs10.x",
            "Description": "new version"
        },
        {
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "Version": "2",
            "CodeSha256": "sU0cJ2/hOZevwV/lTxCuQqK3gDZP3i8gUoqUUVRmY6E=",
            "FunctionName": "my-function",
            "VpcConfig": {
                "SubnetIds": [],
                "VpcId": "",
                "SecurityGroupIds": []
            },
            "MemorySize": 256,
            "RevisionId": "cd669f21-0f3d-4e1c-9566-948837f2e2ea",
            "CodeSize": 266,
            "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:2",
            "Handler": "index.handler",
            "Role": "arn:aws:iam::123456789012:role/service-role/helloWorldPython-role-uy3l9qyq",
            "Timeout": 3,
            "LastModified": "2019-10-01T16:47:28.490+0000",
            "Runtime": "nodejs10.x",
            "Description": "newer version"
        }
    ]
}
```
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [ListVersionsByFunction](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/list-versions-by-function.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example returns the list of version specific configurations for each version of the Lambda Function.**  

```
Get-LMVersionsByFunction -FunctionName "MylambdaFunction123"
```
**Output:**  

```
FunctionName        Runtime   MemorySize Timeout CodeSize LastModified                 RoleName
------------        -------   ---------- ------- -------- ------------                 --------
MylambdaFunction123 python3.8        128     600      659 2020-01-10T03:20:56.390+0000 lambda
MylambdaFunction123 python3.8        128       5     1426 2019-12-25T09:19:02.238+0000 lambda
MylambdaFunction123 python3.8        128       5     1426 2019-12-25T09:39:36.779+0000 lambda
MylambdaFunction123 python3.8        128     600     1426 2019-12-25T09:52:59.872+0000 lambda
```
+  For API details, see [ListVersionsByFunction](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example returns the list of version specific configurations for each version of the Lambda Function.**  

```
Get-LMVersionsByFunction -FunctionName "MylambdaFunction123"
```
**Output:**  

```
FunctionName        Runtime   MemorySize Timeout CodeSize LastModified                 RoleName
------------        -------   ---------- ------- -------- ------------                 --------
MylambdaFunction123 python3.8        128     600      659 2020-01-10T03:20:56.390+0000 lambda
MylambdaFunction123 python3.8        128       5     1426 2019-12-25T09:19:02.238+0000 lambda
MylambdaFunction123 python3.8        128       5     1426 2019-12-25T09:39:36.779+0000 lambda
MylambdaFunction123 python3.8        128     600     1426 2019-12-25T09:52:59.872+0000 lambda
```
+  For API details, see [ListVersionsByFunction](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `PublishVersion` with a CLI
<a name="example_lambda_PublishVersion_section"></a>

The following code examples show how to use `PublishVersion`.

------
#### [ CLI ]

**AWS CLI**  
**To publish a new version of a function**  
The following `publish-version` example publishes a new version of the `my-function` Lambda function.  

```
aws lambda publish-version \
    --function-name my-function
```
Output:  

```
{
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "dBG9m8SGdmlEjw/JYXlhhvCrAv5TxvXsbL/RMr0fT/I=",
    "FunctionName": "my-function",
    "CodeSize": 294,
    "RevisionId": "f31d3d39-cc63-4520-97d4-43cd44c94c20",
    "MemorySize": 128,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:3",
    "Version": "2",
    "Role": "arn:aws:iam::123456789012:role/service-role/MyTestFunction-role-zgur6bf4",
    "Timeout": 3,
    "LastModified": "2019-09-23T18:32:33.857+0000",
    "Handler": "my-function.handler",
    "Runtime": "nodejs10.x",
    "Description": ""
}
```
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [PublishVersion](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/publish-version.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example creates a version for the existing snapshot of Lambda Function Code**  

```
Publish-LMVersion -FunctionName "MylambdaFunction123" -Description "Publishing Existing Snapshot of function code as a  new version through Powershell"
```
+  For API details, see [PublishVersion](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example creates a version for the existing snapshot of Lambda Function Code**  

```
Publish-LMVersion -FunctionName "MylambdaFunction123" -Description "Publishing Existing Snapshot of function code as a  new version through Powershell"
```
+  For API details, see [PublishVersion](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `PutFunctionConcurrency` with a CLI
<a name="example_lambda_PutFunctionConcurrency_section"></a>

The following code examples show how to use `PutFunctionConcurrency`.

------
#### [ CLI ]

**AWS CLI**  
**To configure a reserved concurrency limit for a function**  
The following `put-function-concurrency` example configures 100 reserved concurrent executions for the `my-function` function.  

```
aws lambda put-function-concurrency \
    --function-name  my-function  \
    --reserved-concurrent-executions 100
```
Output:  

```
{
    "ReservedConcurrentExecutions": 100
}
```
For more information, see [Reserving Concurrency for a Lambda Function](https://docs.aws.amazon.com/lambda/latest/dg/per-function-concurrency.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [PutFunctionConcurrency](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/put-function-concurrency.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example applies the concurrency settings for the Function as a whole.**  

```
Write-LMFunctionConcurrency -FunctionName "MylambdaFunction123" -ReservedConcurrentExecution 100
```
+  For API details, see [PutFunctionConcurrency](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example applies the concurrency settings for the Function as a whole.**  

```
Write-LMFunctionConcurrency -FunctionName "MylambdaFunction123" -ReservedConcurrentExecution 100
```
+  For API details, see [PutFunctionConcurrency](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `PutProvisionedConcurrencyConfig` with a CLI
<a name="example_lambda_PutProvisionedConcurrencyConfig_section"></a>

The following code examples show how to use `PutProvisionedConcurrencyConfig`.

------
#### [ CLI ]

**AWS CLI**  
**To allocate provisioned concurrency**  
The following `put-provisioned-concurrency-config` example allocates 100 provisioned concurrency for the `BLUE` alias of the specified function.  

```
aws lambda put-provisioned-concurrency-config \
    --function-name my-function \
    --qualifier BLUE \
    --provisioned-concurrent-executions 100
```
Output:  

```
{
    "Requested ProvisionedConcurrentExecutions": 100,
    "Allocated ProvisionedConcurrentExecutions": 0,
    "Status": "IN_PROGRESS",
    "LastModified": "2019-11-21T19:32:12+0000"
}
```
+  For API details, see [PutProvisionedConcurrencyConfig](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/put-provisioned-concurrency-config.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example adds a provisioned concurrency configuration to a Function's Alias**  

```
Write-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -ProvisionedConcurrentExecution 20 -Qualifier "NewAlias1"
```
+  For API details, see [PutProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example adds a provisioned concurrency configuration to a Function's Alias**  

```
Write-LMProvisionedConcurrencyConfig -FunctionName "MylambdaFunction123" -ProvisionedConcurrentExecution 20 -Qualifier "NewAlias1"
```
+  For API details, see [PutProvisionedConcurrencyConfig](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `RemovePermission` with a CLI
<a name="example_lambda_RemovePermission_section"></a>

The following code examples show how to use `RemovePermission`.

------
#### [ CLI ]

**AWS CLI**  
**To remove permissions from an existing Lambda function**  
The following `remove-permission` example removes permission to invoke a function named `my-function`.  

```
aws lambda remove-permission \
    --function-name my-function \
    --statement-id sns
```
This command produces no output.  
For more information, see [Using Resource-based Policies for AWS Lambda](https://docs.aws.amazon.com/lambda/latest/dg/access-control-resource-based.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [RemovePermission](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/remove-permission.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example removes the function policy for the specified StatementId of a Lambda Function.**  

```
$policy =  Get-LMPolicy -FunctionName "MylambdaFunction123" -Select Policy | ConvertFrom-Json| Select-Object -ExpandProperty Statement
Remove-LMPermission -FunctionName "MylambdaFunction123" -StatementId $policy[0].Sid
```
+  For API details, see [RemovePermission](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example removes the function policy for the specified StatementId of a Lambda Function.**  

```
$policy =  Get-LMPolicy -FunctionName "MylambdaFunction123" -Select Policy | ConvertFrom-Json| Select-Object -ExpandProperty Statement
Remove-LMPermission -FunctionName "MylambdaFunction123" -StatementId $policy[0].Sid
```
+  For API details, see [RemovePermission](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `TagResource` with a CLI
<a name="example_lambda_TagResource_section"></a>

The following code examples show how to use `TagResource`.

------
#### [ CLI ]

**AWS CLI**  
**To add tags to an existing Lambda function**  
The following `tag-resource` example adds a tag with the key name `DEPARTMENT` and a value of `Department A` to the specified Lambda function.  

```
aws lambda tag-resource \
    --resource arn:aws:lambda:us-west-2:123456789012:function:my-function \
    --tags "DEPARTMENT=Department A"
```
This command produces no output.  
For more information, see [Tagging Lambda Functions](https://docs.aws.amazon.com/lambda/latest/dg/tagging.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [TagResource](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/tag-resource.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: Adds the three tags (Washington, Oregon and California) and their associated values to the specified function identified by its ARN.**  

```
Add-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction" -Tag @{ "Washington" = "Olympia"; "Oregon" = "Salem"; "California" = "Sacramento" }
```
+  For API details, see [TagResource](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: Adds the three tags (Washington, Oregon and California) and their associated values to the specified function identified by its ARN.**  

```
Add-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction" -Tag @{ "Washington" = "Olympia"; "Oregon" = "Salem"; "California" = "Sacramento" }
```
+  For API details, see [TagResource](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `UntagResource` with a CLI
<a name="example_lambda_UntagResource_section"></a>

The following code examples show how to use `UntagResource`.

------
#### [ CLI ]

**AWS CLI**  
**To remove tags from an existing Lambda function**  
The following `untag-resource` example removes the tag with the key name `DEPARTMENT` tag from the `my-function` Lambda function.  

```
aws lambda untag-resource \
    --resource arn:aws:lambda:us-west-2:123456789012:function:my-function \
    --tag-keys DEPARTMENT
```
This command produces no output.  
For more information, see [Tagging Lambda Functions](https://docs.aws.amazon.com/lambda/latest/dg/tagging.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [UntagResource](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/untag-resource.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: Removes the supplied tags from a function. The cmdlet will prompt for confirmation before proceeding unless the -Force switch is specified. A single call is made to the service to remove the tags.**  

```
Remove-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction" -TagKey "Washington","Oregon","California"
```
**Example 2: Removes the supplied tags from a function. The cmdlet will prompt for confirmation before proceeding unless the -Force switch is specified. Once call to the service is made per supplied tag.**  

```
"Washington","Oregon","California" | Remove-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction"
```
+  For API details, see [UntagResource](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: Removes the supplied tags from a function. The cmdlet will prompt for confirmation before proceeding unless the -Force switch is specified. A single call is made to the service to remove the tags.**  

```
Remove-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction" -TagKey "Washington","Oregon","California"
```
**Example 2: Removes the supplied tags from a function. The cmdlet will prompt for confirmation before proceeding unless the -Force switch is specified. Once call to the service is made per supplied tag.**  

```
"Washington","Oregon","California" | Remove-LMResourceTag -Resource "arn:aws:lambda:us-west-2:123456789012:function:MyFunction"
```
+  For API details, see [UntagResource](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `UpdateAlias` with a CLI
<a name="example_lambda_UpdateAlias_section"></a>

The following code examples show how to use `UpdateAlias`.

------
#### [ CLI ]

**AWS CLI**  
**To update a function alias**  
The following `update-alias` example updates the alias named `LIVE` to point to version 3 of the `my-function` Lambda function.  

```
aws lambda update-alias \
    --function-name my-function \
    --function-version 3 \
    --name LIVE
```
Output:  

```
{
    "FunctionVersion": "3",
    "Name": "LIVE",
    "AliasArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function:LIVE",
    "RevisionId": "594f41fb-b85f-4c20-95c7-6ca5f2a92c93",
    "Description": "alias for live version of function"
}
```
For more information, see [Configuring AWS Lambda Function Aliases](https://docs.aws.amazon.com/lambda/latest/dg/aliases-intro.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [UpdateAlias](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/update-alias.html) in *AWS CLI Command Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example updates the Configuration of an existing Lambda function Alias. It updates the RoutingConfiguration value to shift 60% (0.6) of traffic to version 1**  

```
Update-LMAlias -FunctionName "MylambdaFunction123" -Description " Alias for version 2" -FunctionVersion 2 -Name "newlabel1" -RoutingConfig_AdditionalVersionWeight @{Name="1";Value="0.6}
```
+  For API details, see [UpdateAlias](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example updates the Configuration of an existing Lambda function Alias. It updates the RoutingConfiguration value to shift 60% (0.6) of traffic to version 1**  

```
Update-LMAlias -FunctionName "MylambdaFunction123" -Description " Alias for version 2" -FunctionVersion 2 -Name "newlabel1" -RoutingConfig_AdditionalVersionWeight @{Name="1";Value="0.6}
```
+  For API details, see [UpdateAlias](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `UpdateFunctionCode` with an AWS SDK or CLI
<a name="example_lambda_UpdateFunctionCode_section"></a>

The following code examples show how to use `UpdateFunctionCode`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Update an existing Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the Lambda function to update.</param>
    /// <param name="bucketName">The bucket where the zip file containing
    /// the Lambda function code is stored.</param>
    /// <param name="key">The key name of the source code file.</param>
    /// <returns>Async Task.</returns>
    public async Task UpdateFunctionCodeAsync(
        string functionName,
        string bucketName,
        string key)
    {
        var functionCodeRequest = new UpdateFunctionCodeRequest
        {
            FunctionName = functionName,
            Publish = true,
            S3Bucket = bucketName,
            S3Key = key,
        };

        var response = await _lambdaService.UpdateFunctionCodeAsync(functionCodeRequest);
        Console.WriteLine($"The Function was last modified at {response.LastModified}.");
    }
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::UpdateFunctionCodeRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        std::ifstream ifstream(CALCULATOR_LAMBDA_CODE.c_str(),
                               std::ios_base::in | std::ios_base::binary);
        if (!ifstream.is_open()) {
            std::cerr << "Error opening file " << INCREMENT_LAMBDA_CODE << "." << std::endl;

#if USE_CPP_LAMBDA_FUNCTION
            std::cerr
                    << "The cpp Lambda function must be built following the instructions in the cpp_lambda/README.md file. "
                    << std::endl;
#endif
            deleteLambdaFunction(client);
            deleteIamRole(clientConfig);
            return false;
        }

        Aws::StringStream buffer;
        buffer << ifstream.rdbuf();
        request.SetZipFile(
                Aws::Utils::ByteBuffer((unsigned char *) buffer.str().c_str(),
                                       buffer.str().length()));
        request.SetPublish(true);

        Aws::Lambda::Model::UpdateFunctionCodeOutcome outcome = client.UpdateFunctionCode(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda code was successfully updated." << std::endl;
        }
        else {
            std::cerr << "Error with Lambda::UpdateFunctionCode. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**To update the code of a Lambda function**  
The following `update-function-code` example replaces the code of the unpublished (\$1LATEST) version of the `my-function` function with the contents of the specified zip file.  

```
aws lambda update-function-code \
    --function-name  my-function \
    --zip-file fileb://my-function.zip
```
Output:  

```
{
    "FunctionName": "my-function",
    "LastModified": "2019-09-26T20:28:40.438+0000",
    "RevisionId": "e52502d4-9320-4688-9cd6-152a6ab7490d",
    "MemorySize": 256,
    "Version": "$LATEST",
    "Role": "arn:aws:iam::123456789012:role/service-role/my-function-role-uy3l9qyq",
    "Timeout": 3,
    "Runtime": "nodejs10.x",
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "5tT2qgzYUHaqwR716pZ2dpkn/0J1FrzJmlKidWoaCgk=",
    "Description": "",
    "VpcConfig": {
        "SubnetIds": [],
        "VpcId": "",
        "SecurityGroupIds": []
    },
    "CodeSize": 304,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
    "Handler": "index.handler"
}
```
For more information, see [AWS Lambda Function Configuration](https://docs.aws.amazon.com/lambda/latest/dg/resource-model.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [UpdateFunctionCode](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/update-function-code.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// UpdateFunctionCode updates the code for the Lambda function specified by functionName.
// The existing code for the Lambda function is entirely replaced by the code in the
// zipPackage buffer. After the update action is called, a lambda.FunctionUpdatedV2Waiter
// is used to wait until the update is successful.
func (wrapper FunctionWrapper) UpdateFunctionCode(ctx context.Context, functionName string, zipPackage *bytes.Buffer) types.State {
	var state types.State
	_, err := wrapper.LambdaClient.UpdateFunctionCode(ctx, &lambda.UpdateFunctionCodeInput{
		FunctionName: aws.String(functionName), ZipFile: zipPackage.Bytes(),
	})
	if err != nil {
		log.Panicf("Couldn't update code for function %v. Here's why: %v\n", functionName, err)
	} else {
		waiter := lambda.NewFunctionUpdatedV2Waiter(wrapper.LambdaClient)
		funcOutput, err := waiter.WaitForOutput(ctx, &lambda.GetFunctionInput{
			FunctionName: aws.String(functionName)}, 1*time.Minute)
		if err != nil {
			log.Panicf("Couldn't wait for function %v to be active. Here's why: %v\n", functionName, err)
		} else {
			state = funcOutput.Configuration.State
		}
	}
	return state
}
```
+  For API details, see [UpdateFunctionCode](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.UpdateFunctionCode) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Updates the code for an AWS Lambda function.
     *
     * @param awsLambda  the AWS Lambda client
     * @param functionName the name of the Lambda function to update
     * @param bucketName the name of the S3 bucket where the function code is located
     * @param key the key (file name) of the function code in the S3 bucket
     * @throws LambdaException if there is an error updating the function code
     */
    public static void updateFunctionCode(LambdaClient awsLambda, String functionName, String bucketName, String key) {
        try {
            LambdaWaiter waiter = awsLambda.waiter();
            UpdateFunctionCodeRequest functionCodeRequest = UpdateFunctionCodeRequest.builder()
                .functionName(functionName)
                .publish(true)
                .s3Bucket(bucketName)
                .s3Key(key)
                .build();

            UpdateFunctionCodeResponse response = awsLambda.updateFunctionCode(functionCodeRequest);
            GetFunctionConfigurationRequest getFunctionConfigRequest = GetFunctionConfigurationRequest.builder()
                .functionName(functionName)
                .build();

            WaiterResponse<GetFunctionConfigurationResponse> waiterResponse = waiter
                .waitUntilFunctionUpdated(getFunctionConfigRequest);
            waiterResponse.matched().response().ifPresent(System.out::println);
            System.out.println("The last modified value is " + response.lastModified());

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const updateFunctionCode = async (funcName, newFunc) => {
  const client = new LambdaClient({});
  const code = await readFile(`${dirname}../functions/${newFunc}.zip`);
  const command = new UpdateFunctionCodeCommand({
    ZipFile: code,
    FunctionName: funcName,
    Architectures: [Architecture.arm64],
    Handler: "index.handler", // Required when sending a .zip file
    PackageType: PackageType.Zip, // Required when sending a .zip file
    Runtime: Runtime.nodejs16x, // Required when sending a .zip file
  });

  return client.send(command);
};
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/UpdateFunctionCodeCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function updateFunctionCode($functionName, $s3Bucket, $s3Key)
    {
        return $this->lambdaClient->updateFunctionCode([
            'FunctionName' => $functionName,
            'S3Bucket' => $s3Bucket,
            'S3Key' => $s3Key,
        ]);
    }
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for PHP API Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: Updates the function named 'MyFunction' with new content contained in the specified zip file. For a C\$1 .NET Core Lambda function the zip file should contain the compiled assembly.**  

```
Update-LMFunctionCode -FunctionName MyFunction -ZipFilename .\UpdatedCode.zip
```
**Example 2: This example is similar to the previous one but uses an Amazon S3 object containing the updated code to update the function.**  

```
Update-LMFunctionCode -FunctionName MyFunction -BucketName amzn-s3-demo-bucket -Key UpdatedCode.zip
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: Updates the function named 'MyFunction' with new content contained in the specified zip file. For a C\$1 .NET Core Lambda function the zip file should contain the compiled assembly.**  

```
Update-LMFunctionCode -FunctionName MyFunction -ZipFilename .\UpdatedCode.zip
```
**Example 2: This example is similar to the previous one but uses an Amazon S3 object containing the updated code to update the function.**  

```
Update-LMFunctionCode -FunctionName MyFunction -BucketName amzn-s3-demo-bucket -Key UpdatedCode.zip
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def update_function_code(self, function_name, deployment_package):
        """
        Updates the code for a Lambda function by submitting a .zip archive that contains
        the code for the function.

        :param function_name: The name of the function to update.
        :param deployment_package: The function code to update, packaged as bytes in
                                   .zip format.
        :return: Data about the update, including the status.
        """
        try:
            response = self.lambda_client.update_function_code(
                FunctionName=function_name, ZipFile=deployment_package
            )
        except ClientError as err:
            logger.error(
                "Couldn't update function %s. Here's why: %s: %s",
                function_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Updates the code for a Lambda function by submitting a .zip archive that contains
  # the code for the function.
  #
  # @param function_name: The name of the function to update.
  # @param deployment_package: The function code to update, packaged as bytes in
  #                            .zip format.
  # @return: Data about the update, including the status.
  def update_function_code(function_name, deployment_package)
    @lambda_client.update_function_code(
      function_name: function_name,
      zip_file: deployment_package
    )
    @lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error updating function code for: #{function_name}:\n #{e.message}")
    nil
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to update:\n #{e.message}")
  end
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** Given a Path to a zip file, update the function's code and wait for the update to finish. */
    pub async fn update_function_code(
        &self,
        zip_file: PathBuf,
        key: String,
    ) -> Result<UpdateFunctionCodeOutput, anyhow::Error> {
        let function_code = self.prepare_function(zip_file, Some(key)).await?;

        info!("Updating code for {}", self.lambda_name);
        let update = self
            .lambda_client
            .update_function_code()
            .function_name(self.lambda_name.clone())
            .s3_bucket(self.bucket.clone())
            .s3_key(function_code.s3_key().unwrap().to_string())
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        Ok(update)
    }

    /**
     * Upload function code from a path to a zip file.
     * The zip file must have an AL2 Linux-compatible binary called `bootstrap`.
     * The easiest way to create such a zip is to use `cargo lambda build --output-format Zip`.
     */
    async fn prepare_function(
        &self,
        zip_file: PathBuf,
        key: Option<String>,
    ) -> Result<FunctionCode, anyhow::Error> {
        let body = ByteStream::from_path(zip_file).await?;

        let key = key.unwrap_or_else(|| format!("{}_code", self.lambda_name));

        info!("Uploading function code to s3://{}/{}", self.bucket, key);
        let _ = self
            .s3_client
            .put_object()
            .bucket(self.bucket.clone())
            .key(key.clone())
            .body(body)
            .send()
            .await?;

        Ok(FunctionCode::builder()
            .s3_bucket(self.bucket.clone())
            .s3_key(key)
            .build())
    }
```
+  For API details, see [UpdateFunctionCode](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.update_function_code) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        oo_result = lo_lmd->updatefunctioncode(     " oo_result is returned for testing purposes. "
              iv_functionname = iv_function_name
              iv_zipfile = io_zip_file ).

        MESSAGE 'Lambda function code updated.' TYPE 'I'.
      CATCH /aws1/cx_lmdcodesigningcfgno00.
        MESSAGE 'Code signing configuration does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodestorageexcdex.
        MESSAGE 'Maximum total code size per account exceeded.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodeverification00.
        MESSAGE 'Code signature failed one or more validation checks for signature mismatch or expiration.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidcodesigex.
        MESSAGE 'Code signature failed the integrity check.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

        let zipUrl = URL(fileURLWithPath: path)
        let zipData: Data

        // Read the function's Zip file.

        do {
            zipData = try Data(contentsOf: zipUrl)
        } catch {
            throw ExampleError.zipFileReadError
        }

        // Update the function's code and wait for the updated version to be
        // ready for use.

        do {
            _ = try await lambdaClient.updateFunctionCode(
                input: UpdateFunctionCodeInput(
                    functionName: functionName,
                    zipFile: zipData
                )
            )
        } catch {
            return false
        }
```
+  For API details, see [UpdateFunctionCode](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/updatefunctioncode(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use `UpdateFunctionConfiguration` with an AWS SDK or CLI
<a name="example_lambda_UpdateFunctionConfiguration_section"></a>

The following code examples show how to use `UpdateFunctionConfiguration`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example: 
+  [Learn the basics](example_lambda_Scenario_GettingStartedFunctions_section.md) 

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/Lambda#code-examples). 

```
    /// <summary>
    /// Update the code of a Lambda function.
    /// </summary>
    /// <param name="functionName">The name of the function to update.</param>
    /// <param name="functionHandler">The code that performs the function's actions.</param>
    /// <param name="environmentVariables">A dictionary of environment variables.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> UpdateFunctionConfigurationAsync(
        string functionName,
        string functionHandler,
        Dictionary<string, string> environmentVariables)
    {
        var request = new UpdateFunctionConfigurationRequest
        {
            Handler = functionHandler,
            FunctionName = functionName,
            Environment = new Amazon.Lambda.Model.Environment { Variables = environmentVariables },
        };

        var response = await _lambdaService.UpdateFunctionConfigurationAsync(request);

        Console.WriteLine(response.LastModified);

        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/DotNetSDKV3/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/lambda#code-examples). 

```
        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region in which the bucket was created (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::Lambda::LambdaClient client(clientConfig);

        Aws::Lambda::Model::UpdateFunctionConfigurationRequest request;
        request.SetFunctionName(LAMBDA_NAME);
        Aws::Lambda::Model::Environment environment;
        environment.AddVariables("LOG_LEVEL", "DEBUG");
        request.SetEnvironment(environment);

        Aws::Lambda::Model::UpdateFunctionConfigurationOutcome outcome = client.UpdateFunctionConfiguration(
                request);

        if (outcome.IsSuccess()) {
            std::cout << "The lambda configuration was successfully updated."
                      << std::endl;
            break;
        }

        else {
            std::cerr << "Error with Lambda::UpdateFunctionConfiguration. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ CLI ]

**AWS CLI**  
**To modify the configuration of a function**  
The following `update-function-configuration` example modifies the memory size to be 256 MB for the unpublished (\$1LATEST) version of the `my-function` function.  

```
aws lambda update-function-configuration \
    --function-name  my-function \
    --memory-size 256
```
Output:  

```
{
    "FunctionName": "my-function",
    "LastModified": "2019-09-26T20:28:40.438+0000",
    "RevisionId": "e52502d4-9320-4688-9cd6-152a6ab7490d",
    "MemorySize": 256,
    "Version": "$LATEST",
    "Role": "arn:aws:iam::123456789012:role/service-role/my-function-role-uy3l9qyq",
    "Timeout": 3,
    "Runtime": "nodejs10.x",
    "TracingConfig": {
        "Mode": "PassThrough"
    },
    "CodeSha256": "5tT2qgzYUHaqwR716pZ2dpkn/0J1FrzJmlKidWoaCgk=",
    "Description": "",
    "VpcConfig": {
        "SubnetIds": [],
        "VpcId": "",
        "SecurityGroupIds": []
    },
    "CodeSize": 304,
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
    "Handler": "index.handler"
}
```
For more information, see [AWS Lambda Function Configuration](https://docs.aws.amazon.com/lambda/latest/dg/resource-model.html) in the *AWS Lambda Developer Guide*.  
+  For API details, see [UpdateFunctionConfiguration](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/lambda/update-function-configuration.html) in *AWS CLI Command Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/lambda#code-examples). 

```
import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"log"
	"time"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/lambda"
	"github.com/aws/aws-sdk-go-v2/service/lambda/types"
)

// FunctionWrapper encapsulates function actions used in the examples.
// It contains an AWS Lambda service client that is used to perform user actions.
type FunctionWrapper struct {
	LambdaClient *lambda.Client
}



// UpdateFunctionConfiguration updates a map of environment variables configured for
// the Lambda function specified by functionName.
func (wrapper FunctionWrapper) UpdateFunctionConfiguration(ctx context.Context, functionName string, envVars map[string]string) {
	_, err := wrapper.LambdaClient.UpdateFunctionConfiguration(ctx, &lambda.UpdateFunctionConfigurationInput{
		FunctionName: aws.String(functionName),
		Environment:  &types.Environment{Variables: envVars},
	})
	if err != nil {
		log.Panicf("Couldn't update configuration for %v. Here's why: %v", functionName, err)
	}
}
```
+  For API details, see [UpdateFunctionConfiguration](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/lambda#Client.UpdateFunctionConfiguration) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/lambda#code-examples). 

```
    /**
     * Updates the configuration of an AWS Lambda function.
     *
     * @param awsLambda     the {@link LambdaClient} instance to use for the AWS Lambda operation
     * @param functionName  the name of the AWS Lambda function to update
     * @param handler       the new handler for the AWS Lambda function
     *
     * @throws LambdaException if there is an error while updating the function configuration
     */
    public static void updateFunctionConfiguration(LambdaClient awsLambda, String functionName, String handler) {
        try {
            UpdateFunctionConfigurationRequest configurationRequest = UpdateFunctionConfigurationRequest.builder()
                .functionName(functionName)
                .handler(handler)
                .runtime(Runtime.JAVA17)
                .build();

            awsLambda.updateFunctionConfiguration(configurationRequest);

        } catch (LambdaException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/lambda#code-examples). 

```
const updateFunctionConfiguration = (funcName) => {
  const client = new LambdaClient({});
  const config = readFileSync(`${dirname}../functions/config.json`).toString();
  const command = new UpdateFunctionConfigurationCommand({
    ...JSON.parse(config),
    FunctionName: funcName,
  });
  const result = client.send(command);
  waitForFunctionUpdated({ FunctionName: funcName });
  return result;
};
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/lambda/command/UpdateFunctionConfigurationCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/lambda#code-examples). 

```
    public function updateFunctionConfiguration($functionName, $handler, $environment = '')
    {
        return $this->lambdaClient->updateFunctionConfiguration([
            'FunctionName' => $functionName,
            'Handler' => "$handler.lambda_handler",
            'Environment' => $environment,
        ]);
    }
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for PHP API Reference*. 

------
#### [ PowerShell ]

**Tools for PowerShell V4**  
**Example 1: This example updates the existing Lambda Function Configuration**  

```
Update-LMFunctionConfiguration -FunctionName "MylambdaFunction123" -Handler "lambda_function.launch_instance" -Timeout 600 -Environment_Variable @{ "envvar1"="value";"envvar2"="value" } -Role arn:aws:iam::123456789101:role/service-role/lambda -DeadLetterConfig_TargetArn arn:aws:sns:us-east-1: 123456789101:MyfirstTopic
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/powershell/v4/reference) in *AWS Tools for PowerShell Cmdlet Reference (V4)*. 

**Tools for PowerShell V5**  
**Example 1: This example updates the existing Lambda Function Configuration**  

```
Update-LMFunctionConfiguration -FunctionName "MylambdaFunction123" -Handler "lambda_function.launch_instance" -Timeout 600 -Environment_Variable @{ "envvar1"="value";"envvar2"="value" } -Role arn:aws:iam::123456789101:role/service-role/lambda -DeadLetterConfig_TargetArn arn:aws:sns:us-east-1: 123456789101:MyfirstTopic
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/powershell/v5/reference) in *AWS Tools for PowerShell Cmdlet Reference (V5)*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#code-examples). 

```
class LambdaWrapper:
    def __init__(self, lambda_client, iam_resource):
        self.lambda_client = lambda_client
        self.iam_resource = iam_resource


    def update_function_configuration(self, function_name, env_vars):
        """
        Updates the environment variables for a Lambda function.

        :param function_name: The name of the function to update.
        :param env_vars: A dict of environment variables to update.
        :return: Data about the update, including the status.
        """
        try:
            response = self.lambda_client.update_function_configuration(
                FunctionName=function_name, Environment={"Variables": env_vars}
            )
        except ClientError as err:
            logger.error(
                "Couldn't update function configuration %s. Here's why: %s: %s",
                function_name,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return response
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples). 

```
class LambdaWrapper
  attr_accessor :lambda_client, :cloudwatch_client, :iam_client

  def initialize
    @lambda_client = Aws::Lambda::Client.new
    @cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
    @iam_client = Aws::IAM::Client.new(region: 'us-east-1')
    @logger = Logger.new($stdout)
    @logger.level = Logger::WARN
  end

  # Updates the environment variables for a Lambda function.
  # @param function_name: The name of the function to update.
  # @param log_level: The log level of the function.
  # @return: Data about the update, including the status.
  def update_function_configuration(function_name, log_level)
    @lambda_client.update_function_configuration({
                                                   function_name: function_name,
                                                   environment: {
                                                     variables: {
                                                       'LOG_LEVEL' => log_level
                                                     }
                                                   }
                                                 })
    @lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
      w.max_attempts = 5
      w.delay = 5
    end
  rescue Aws::Lambda::Errors::ServiceException => e
    @logger.error("There was an error updating configurations for #{function_name}:\n #{e.message}")
  rescue Aws::Waiters::Errors::WaiterFailed => e
    @logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
  end
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for Ruby API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/lambda#code-examples). 

```
    /** Update the environment for a function. */
    pub async fn update_function_configuration(
        &self,
        environment: Environment,
    ) -> Result<UpdateFunctionConfigurationOutput, anyhow::Error> {
        info!(
            ?environment,
            "Updating environment for {}", self.lambda_name
        );
        let updated = self
            .lambda_client
            .update_function_configuration()
            .function_name(self.lambda_name.clone())
            .environment(environment)
            .send()
            .await
            .map_err(anyhow::Error::from)?;

        self.wait_for_function_ready().await?;

        Ok(updated)
    }
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.rs/aws-sdk-lambda/latest/aws_sdk_lambda/client/struct.Client.html#method.update_function_configuration) in *AWS SDK for Rust API reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/lmd#code-examples). 

```
    TRY.
        oo_result = lo_lmd->updatefunctionconfiguration(     " oo_result is returned for testing purposes. "
              iv_functionname = iv_function_name
              iv_runtime = iv_runtime
              iv_description  = 'Updated Lambda function'
              iv_memorysize  = iv_memory_size ).

        MESSAGE 'Lambda function configuration/settings updated.' TYPE 'I'.
      CATCH /aws1/cx_lmdcodesigningcfgno00.
        MESSAGE 'Code signing configuration does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdcodeverification00.
        MESSAGE 'Code signature failed one or more validation checks for signature mismatch or expiration.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvalidcodesigex.
        MESSAGE 'Code signature failed the integrity check.' TYPE 'E'.
      CATCH /aws1/cx_lmdinvparamvalueex.
        MESSAGE 'The request contains a non-valid parameter.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourceconflictex.
        MESSAGE 'Resource already exists or another operation is in progress.' TYPE 'E'.
      CATCH /aws1/cx_lmdresourcenotfoundex.
        MESSAGE 'The requested resource does not exist.' TYPE 'E'.
      CATCH /aws1/cx_lmdserviceexception.
        MESSAGE 'An internal problem was encountered by the AWS Lambda service.' TYPE 'E'.
      CATCH /aws1/cx_lmdtoomanyrequestsex.
        MESSAGE 'The maximum request throughput was reached.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/lambda/basics#code-examples). 

```
import AWSClientRuntime
import AWSLambda
import Foundation

    /// Tell the server-side component to log debug output by setting its
    /// environment's `LOG_LEVEL` to `DEBUG`.
    ///
    /// - Parameters:
    ///   - lambdaClient: The `LambdaClient` to use.
    ///   - functionName: The name of the AWS Lambda function to enable debug
    ///     logging for.
    ///
    /// - Throws: `ExampleError.environmentResponseMissingError`,
    ///   `ExampleError.updateFunctionConfigurationError`,
    ///   `ExampleError.environmentVariablesMissingError`,
    ///   `ExampleError.logLevelIncorrectError`,
    ///   `ExampleError.updateFunctionConfigurationError`
    func enableDebugLogging(lambdaClient: LambdaClient, functionName: String) async throws {
        let envVariables = [
            "LOG_LEVEL": "DEBUG"
        ]
        let environment = LambdaClientTypes.Environment(variables: envVariables)

        do {
            let output = try await lambdaClient.updateFunctionConfiguration(
                input: UpdateFunctionConfigurationInput(
                    environment: environment,
                    functionName: functionName
                )
            )

            guard let response = output.environment else {
                throw ExampleError.environmentResponseMissingError
            }

            if response.error != nil {
                throw ExampleError.updateFunctionConfigurationError
            }

            guard let retVariables = response.variables else {
                throw ExampleError.environmentVariablesMissingError
            }

            for envVar in retVariables {
                if envVar.key == "LOG_LEVEL" && envVar.value != "DEBUG" {
                    print("*** Log level is not set to DEBUG!")
                    throw ExampleError.logLevelIncorrectError
                }
            }
        } catch {
            throw ExampleError.updateFunctionConfigurationError
        }
    }
```
+  For API details, see [UpdateFunctionConfiguration](https://sdk.amazonaws.com/swift/api/awslambda/latest/documentation/awslambda/lambdaclient/updatefunctionconfiguration(input:)) in *AWS SDK for Swift API reference*. 

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Scenarios for Lambda using AWS SDKs
<a name="service_code_examples_scenarios"></a>

The following code examples show you how to implement common scenarios in Lambda with AWS SDKs. These scenarios show you how to accomplish specific tasks by calling multiple functions within Lambda or combined with other AWS services. Each scenario includes a link to the complete source code, where you can find instructions on how to set up and run the code. 

Scenarios target an intermediate level of experience to help you understand service actions in context.

**Topics**
+ [Automatically confirm known users with a Lambda function](example_cross_CognitoAutoConfirmUser_section.md)
+ [Automatically migrate known users with a Lambda function](example_cross_CognitoAutoMigrateUser_section.md)
+ [Create a REST API to track COVID-19 data](example_cross_ApiGatewayDataTracker_section.md)
+ [Create a REST API with Lambda proxy integration](example_api_gateway_GettingStarted_087_section.md)
+ [Create a lending library REST API](example_cross_AuroraRestLendingLibrary_section.md)
+ [Create a messenger application](example_cross_StepFunctionsMessenger_section.md)
+ [Create a serverless application to manage photos](example_cross_PAM_section.md)
+ [Create a websocket chat application](example_cross_ApiGatewayWebsocketChat_section.md)
+ [Create an application to analyze customer feedback](example_cross_FSA_section.md)
+ [Creating a CloudWatch dashboard with function name as a variable](example_cloudwatch_GettingStarted_031_section.md)
+ [Creating your first Lambda function](example_lambda_GettingStarted_019_section.md)
+ [Invoke a Lambda function from a browser](example_cross_LambdaForBrowser_section.md)
+ [Transform data with S3 Object Lambda](example_cross_ServerlessS3DataTransformation_section.md)
+ [Use API Gateway to invoke a Lambda function](example_cross_LambdaAPIGateway_section.md)
+ [Use Step Functions to invoke Lambda functions](example_cross_ServerlessWorkflows_section.md)
+ [Use scheduled events to invoke a Lambda function](example_cross_LambdaScheduledEvents_section.md)
+ [Use the Neptune API to query graph data](example_cross_Neptune_Query_section.md)
+ [Using property variables in CloudWatch dashboards to monitor multiple Lambda functions](example_iam_GettingStarted_032_section.md)
+ [Write custom activity data with a Lambda function after Amazon Cognito user authentication](example_cross_CognitoCustomActivityLog_section.md)

# Automatically confirm known Amazon Cognito users with a Lambda function using an AWS SDK
<a name="example_cross_CognitoAutoConfirmUser_section"></a>

The following code examples show how to automatically confirm known Amazon Cognito users with a Lambda function.
+ Configure a user pool to call a Lambda function for the `PreSignUp` trigger.
+ Sign up a user with Amazon Cognito.
+ The Lambda function scans a DynamoDB table and automatically confirms known users.
+ Sign in as the new user, then clean up resources.

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/workflows/user_pools_and_lambda_triggers#code-examples). 
Run an interactive scenario at a command prompt.  

```
import (
	"context"
	"errors"
	"log"
	"strings"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// AutoConfirm separates the steps of this scenario into individual functions so that
// they are simpler to read and understand.
type AutoConfirm struct {
	helper       IScenarioHelper
	questioner   demotools.IQuestioner
	resources    Resources
	cognitoActor *actions.CognitoActions
}

// NewAutoConfirm constructs a new auto confirm runner.
func NewAutoConfirm(sdkConfig aws.Config, questioner demotools.IQuestioner, helper IScenarioHelper) AutoConfirm {
	scenario := AutoConfirm{
		helper:       helper,
		questioner:   questioner,
		resources:    Resources{},
		cognitoActor: &actions.CognitoActions{CognitoClient: cognitoidentityprovider.NewFromConfig(sdkConfig)},
	}
	scenario.resources.init(scenario.cognitoActor, questioner)
	return scenario
}

// AddPreSignUpTrigger adds a Lambda handler as an invocation target for the PreSignUp trigger.
func (runner *AutoConfirm) AddPreSignUpTrigger(ctx context.Context, userPoolId string, functionArn string) {
	log.Printf("Let's add a Lambda function to handle the PreSignUp trigger from Cognito.\n" +
		"This trigger happens when a user signs up, and lets your function take action before the main Cognito\n" +
		"sign up processing occurs.\n")
	err := runner.cognitoActor.UpdateTriggers(
		ctx, userPoolId,
		actions.TriggerInfo{Trigger: actions.PreSignUp, HandlerArn: aws.String(functionArn)})
	if err != nil {
		panic(err)
	}
	log.Printf("Lambda function %v added to user pool %v to handle the PreSignUp trigger.\n",
		functionArn, userPoolId)
}

// SignUpUser signs up a user from the known user table with a password you specify.
func (runner *AutoConfirm) SignUpUser(ctx context.Context, clientId string, usersTable string) (string, string) {
	log.Println("Let's sign up a user to your Cognito user pool. When the user's email matches an email in the\n" +
		"DynamoDB known users table, it is automatically verified and the user is confirmed.")

	knownUsers, err := runner.helper.GetKnownUsers(ctx, usersTable)
	if err != nil {
		panic(err)
	}
	userChoice := runner.questioner.AskChoice("Which user do you want to use?\n", knownUsers.UserNameList())
	user := knownUsers.Users[userChoice]

	var signedUp bool
	var userConfirmed bool
	password := runner.questioner.AskPassword("Enter a password that has at least eight characters, uppercase, lowercase, numbers and symbols.\n"+
		"(the password will not display as you type):", 8)
	for !signedUp {
		log.Printf("Signing up user '%v' with email '%v' to Cognito.\n", user.UserName, user.UserEmail)
		userConfirmed, err = runner.cognitoActor.SignUp(ctx, clientId, user.UserName, password, user.UserEmail)
		if err != nil {
			var invalidPassword *types.InvalidPasswordException
			if errors.As(err, &invalidPassword) {
				password = runner.questioner.AskPassword("Enter another password:", 8)
			} else {
				panic(err)
			}
		} else {
			signedUp = true
		}
	}
	log.Printf("User %v signed up, confirmed = %v.\n", user.UserName, userConfirmed)

	log.Println(strings.Repeat("-", 88))

	return user.UserName, password
}

// SignInUser signs in a user.
func (runner *AutoConfirm) SignInUser(ctx context.Context, clientId string, userName string, password string) string {
	runner.questioner.Ask("Press Enter when you're ready to continue.")
	log.Printf("Let's sign in as %v...\n", userName)
	authResult, err := runner.cognitoActor.SignIn(ctx, clientId, userName, password)
	if err != nil {
		panic(err)
	}
	log.Printf("Successfully signed in. Your access token starts with: %v...\n", (*authResult.AccessToken)[:10])
	log.Println(strings.Repeat("-", 88))
	return *authResult.AccessToken
}

// Run runs the scenario.
func (runner *AutoConfirm) Run(ctx context.Context, stackName string) {
	defer func() {
		if r := recover(); r != nil {
			log.Println("Something went wrong with the demo.")
			runner.resources.Cleanup(ctx)
		}
	}()

	log.Println(strings.Repeat("-", 88))
	log.Printf("Welcome\n")

	log.Println(strings.Repeat("-", 88))

	stackOutputs, err := runner.helper.GetStackOutputs(ctx, stackName)
	if err != nil {
		panic(err)
	}
	runner.resources.userPoolId = stackOutputs["UserPoolId"]
	runner.helper.PopulateUserTable(ctx, stackOutputs["TableName"])

	runner.AddPreSignUpTrigger(ctx, stackOutputs["UserPoolId"], stackOutputs["AutoConfirmFunctionArn"])
	runner.resources.triggers = append(runner.resources.triggers, actions.PreSignUp)
	userName, password := runner.SignUpUser(ctx, stackOutputs["UserPoolClientId"], stackOutputs["TableName"])
	runner.helper.ListRecentLogEvents(ctx, stackOutputs["AutoConfirmFunction"])
	runner.resources.userAccessTokens = append(runner.resources.userAccessTokens,
		runner.SignInUser(ctx, stackOutputs["UserPoolClientId"], userName, password))

	runner.resources.Cleanup(ctx)

	log.Println(strings.Repeat("-", 88))
	log.Println("Thanks for watching!")
	log.Println(strings.Repeat("-", 88))
}
```
Handle the `PreSignUp` trigger with a Lambda function.  

```
import (
	"context"
	"log"
	"os"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	dynamodbtypes "github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)

const TABLE_NAME = "TABLE_NAME"

// UserInfo defines structured user data that can be marshalled to a DynamoDB format.
type UserInfo struct {
	UserName  string `dynamodbav:"UserName"`
	UserEmail string `dynamodbav:"UserEmail"`
}

// GetKey marshals the user email value to a DynamoDB key format.
func (user UserInfo) GetKey() map[string]dynamodbtypes.AttributeValue {
	userEmail, err := attributevalue.Marshal(user.UserEmail)
	if err != nil {
		panic(err)
	}
	return map[string]dynamodbtypes.AttributeValue{"UserEmail": userEmail}
}

type handler struct {
	dynamoClient *dynamodb.Client
}

// HandleRequest handles the PreSignUp event by looking up a user in an Amazon DynamoDB table and
// specifying whether they should be confirmed and verified.
func (h *handler) HandleRequest(ctx context.Context, event events.CognitoEventUserPoolsPreSignup) (events.CognitoEventUserPoolsPreSignup, error) {
	log.Printf("Received presignup from %v for user '%v'", event.TriggerSource, event.UserName)
	if event.TriggerSource != "PreSignUp_SignUp" {
		// Other trigger sources, such as PreSignUp_AdminInitiateAuth, ignore the response from this handler.
		return event, nil
	}
	tableName := os.Getenv(TABLE_NAME)
	user := UserInfo{
		UserEmail: event.Request.UserAttributes["email"],
	}
	log.Printf("Looking up email %v in table %v.\n", user.UserEmail, tableName)
	output, err := h.dynamoClient.GetItem(ctx, &dynamodb.GetItemInput{
		Key:       user.GetKey(),
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Error looking up email %v.\n", user.UserEmail)
		return event, err
	}
	if output.Item == nil {
		log.Printf("Email %v not found. Email verification is required.\n", user.UserEmail)
		return event, err
	}

	err = attributevalue.UnmarshalMap(output.Item, &user)
	if err != nil {
		log.Printf("Couldn't unmarshal DynamoDB item. Here's why: %v\n", err)
		return event, err
	}

	if user.UserName != event.UserName {
		log.Printf("UserEmail %v found, but stored UserName '%v' does not match supplied UserName '%v'. Verification is required.\n",
			user.UserEmail, user.UserName, event.UserName)
	} else {
		log.Printf("UserEmail %v found with matching UserName %v. User is confirmed.\n", user.UserEmail, user.UserName)
		event.Response.AutoConfirmUser = true
		event.Response.AutoVerifyEmail = true
	}

	return event, err
}

func main() {
	ctx := context.Background()
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		log.Panicln(err)
	}
	h := handler{
		dynamoClient: dynamodb.NewFromConfig(sdkConfig),
	}
	lambda.Start(h.HandleRequest)
}
```
Create a struct that performs common tasks.  

```
import (
	"context"
	"log"
	"strings"
	"time"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// IScenarioHelper defines common functions used by the workflows in this example.
type IScenarioHelper interface {
	Pause(secs int)
	GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error)
	PopulateUserTable(ctx context.Context, tableName string)
	GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error)
	AddKnownUser(ctx context.Context, tableName string, user actions.User)
	ListRecentLogEvents(ctx context.Context, functionName string)
}

// ScenarioHelper contains AWS wrapper structs used by the workflows in this example.
type ScenarioHelper struct {
	questioner  demotools.IQuestioner
	dynamoActor *actions.DynamoActions
	cfnActor    *actions.CloudFormationActions
	cwlActor    *actions.CloudWatchLogsActions
	isTestRun   bool
}

// NewScenarioHelper constructs a new scenario helper.
func NewScenarioHelper(sdkConfig aws.Config, questioner demotools.IQuestioner) ScenarioHelper {
	scenario := ScenarioHelper{
		questioner:  questioner,
		dynamoActor: &actions.DynamoActions{DynamoClient: dynamodb.NewFromConfig(sdkConfig)},
		cfnActor:    &actions.CloudFormationActions{CfnClient: cloudformation.NewFromConfig(sdkConfig)},
		cwlActor:    &actions.CloudWatchLogsActions{CwlClient: cloudwatchlogs.NewFromConfig(sdkConfig)},
	}
	return scenario
}

// Pause waits for the specified number of seconds.
func (helper ScenarioHelper) Pause(secs int) {
	if !helper.isTestRun {
		time.Sleep(time.Duration(secs) * time.Second)
	}
}

// GetStackOutputs gets the outputs from the specified CloudFormation stack in a structured format.
func (helper ScenarioHelper) GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error) {
	return helper.cfnActor.GetOutputs(ctx, stackName), nil
}

// PopulateUserTable fills the known user table with example data.
func (helper ScenarioHelper) PopulateUserTable(ctx context.Context, tableName string) {
	log.Printf("First, let's add some users to the DynamoDB %v table we'll use for this example.\n", tableName)
	err := helper.dynamoActor.PopulateTable(ctx, tableName)
	if err != nil {
		panic(err)
	}
}

// GetKnownUsers gets the users from the known users table in a structured format.
func (helper ScenarioHelper) GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error) {
	knownUsers, err := helper.dynamoActor.Scan(ctx, tableName)
	if err != nil {
		log.Printf("Couldn't get known users from table %v. Here's why: %v\n", tableName, err)
	}
	return knownUsers, err
}

// AddKnownUser adds a user to the known users table.
func (helper ScenarioHelper) AddKnownUser(ctx context.Context, tableName string, user actions.User) {
	log.Printf("Adding user '%v' with email '%v' to the DynamoDB known users table...\n",
		user.UserName, user.UserEmail)
	err := helper.dynamoActor.AddUser(ctx, tableName, user)
	if err != nil {
		panic(err)
	}
}

// ListRecentLogEvents gets the most recent log stream and events for the specified Lambda function and displays them.
func (helper ScenarioHelper) ListRecentLogEvents(ctx context.Context, functionName string) {
	log.Println("Waiting a few seconds to let Lambda write to CloudWatch Logs...")
	helper.Pause(10)
	log.Println("Okay, let's check the logs to find what's happened recently with your Lambda function.")
	logStream, err := helper.cwlActor.GetLatestLogStream(ctx, functionName)
	if err != nil {
		panic(err)
	}
	log.Printf("Getting some recent events from log stream %v\n", *logStream.LogStreamName)
	events, err := helper.cwlActor.GetLogEvents(ctx, functionName, *logStream.LogStreamName, 10)
	if err != nil {
		panic(err)
	}
	for _, event := range events {
		log.Printf("\t%v", *event.Message)
	}
	log.Println(strings.Repeat("-", 88))
}
```
Create a struct that wraps Amazon Cognito actions.  

```
import (
	"context"
	"errors"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
)

type CognitoActions struct {
	CognitoClient *cognitoidentityprovider.Client
}



// Trigger and TriggerInfo define typed data for updating an Amazon Cognito trigger.
type Trigger int

const (
	PreSignUp Trigger = iota
	UserMigration
	PostAuthentication
)

type TriggerInfo struct {
	Trigger    Trigger
	HandlerArn *string
}

// UpdateTriggers adds or removes Lambda triggers for a user pool. When a trigger is specified with a `nil` value,
// it is removed from the user pool.
func (actor CognitoActions) UpdateTriggers(ctx context.Context, userPoolId string, triggers ...TriggerInfo) error {
	output, err := actor.CognitoClient.DescribeUserPool(ctx, &cognitoidentityprovider.DescribeUserPoolInput{
		UserPoolId: aws.String(userPoolId),
	})
	if err != nil {
		log.Printf("Couldn't get info about user pool %v. Here's why: %v\n", userPoolId, err)
		return err
	}
	lambdaConfig := output.UserPool.LambdaConfig
	for _, trigger := range triggers {
		switch trigger.Trigger {
		case PreSignUp:
			lambdaConfig.PreSignUp = trigger.HandlerArn
		case UserMigration:
			lambdaConfig.UserMigration = trigger.HandlerArn
		case PostAuthentication:
			lambdaConfig.PostAuthentication = trigger.HandlerArn
		}
	}
	_, err = actor.CognitoClient.UpdateUserPool(ctx, &cognitoidentityprovider.UpdateUserPoolInput{
		UserPoolId:   aws.String(userPoolId),
		LambdaConfig: lambdaConfig,
	})
	if err != nil {
		log.Printf("Couldn't update user pool %v. Here's why: %v\n", userPoolId, err)
	}
	return err
}



// SignUp signs up a user with Amazon Cognito.
func (actor CognitoActions) SignUp(ctx context.Context, clientId string, userName string, password string, userEmail string) (bool, error) {
	confirmed := false
	output, err := actor.CognitoClient.SignUp(ctx, &cognitoidentityprovider.SignUpInput{
		ClientId: aws.String(clientId),
		Password: aws.String(password),
		Username: aws.String(userName),
		UserAttributes: []types.AttributeType{
			{Name: aws.String("email"), Value: aws.String(userEmail)},
		},
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't sign up user %v. Here's why: %v\n", userName, err)
		}
	} else {
		confirmed = output.UserConfirmed
	}
	return confirmed, err
}



// SignIn signs in a user to Amazon Cognito using a username and password authentication flow.
func (actor CognitoActions) SignIn(ctx context.Context, clientId string, userName string, password string) (*types.AuthenticationResultType, error) {
	var authResult *types.AuthenticationResultType
	output, err := actor.CognitoClient.InitiateAuth(ctx, &cognitoidentityprovider.InitiateAuthInput{
		AuthFlow:       "USER_PASSWORD_AUTH",
		ClientId:       aws.String(clientId),
		AuthParameters: map[string]string{"USERNAME": userName, "PASSWORD": password},
	})
	if err != nil {
		var resetRequired *types.PasswordResetRequiredException
		if errors.As(err, &resetRequired) {
			log.Println(*resetRequired.Message)
		} else {
			log.Printf("Couldn't sign in user %v. Here's why: %v\n", userName, err)
		}
	} else {
		authResult = output.AuthenticationResult
	}
	return authResult, err
}



// ForgotPassword starts a password recovery flow for a user. This flow typically sends a confirmation code
// to the user's configured notification destination, such as email.
func (actor CognitoActions) ForgotPassword(ctx context.Context, clientId string, userName string) (*types.CodeDeliveryDetailsType, error) {
	output, err := actor.CognitoClient.ForgotPassword(ctx, &cognitoidentityprovider.ForgotPasswordInput{
		ClientId: aws.String(clientId),
		Username: aws.String(userName),
	})
	if err != nil {
		log.Printf("Couldn't start password reset for user '%v'. Here;s why: %v\n", userName, err)
	}
	return output.CodeDeliveryDetails, err
}



// ConfirmForgotPassword confirms a user with a confirmation code and a new password.
func (actor CognitoActions) ConfirmForgotPassword(ctx context.Context, clientId string, code string, userName string, password string) error {
	_, err := actor.CognitoClient.ConfirmForgotPassword(ctx, &cognitoidentityprovider.ConfirmForgotPasswordInput{
		ClientId:         aws.String(clientId),
		ConfirmationCode: aws.String(code),
		Password:         aws.String(password),
		Username:         aws.String(userName),
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't confirm user %v. Here's why: %v", userName, err)
		}
	}
	return err
}



// DeleteUser removes a user from the user pool.
func (actor CognitoActions) DeleteUser(ctx context.Context, userAccessToken string) error {
	_, err := actor.CognitoClient.DeleteUser(ctx, &cognitoidentityprovider.DeleteUserInput{
		AccessToken: aws.String(userAccessToken),
	})
	if err != nil {
		log.Printf("Couldn't delete user. Here's why: %v\n", err)
	}
	return err
}



// AdminCreateUser uses administrator credentials to add a user to a user pool. This method leaves the user
// in a state that requires they enter a new password next time they sign in.
func (actor CognitoActions) AdminCreateUser(ctx context.Context, userPoolId string, userName string, userEmail string) error {
	_, err := actor.CognitoClient.AdminCreateUser(ctx, &cognitoidentityprovider.AdminCreateUserInput{
		UserPoolId:     aws.String(userPoolId),
		Username:       aws.String(userName),
		MessageAction:  types.MessageActionTypeSuppress,
		UserAttributes: []types.AttributeType{{Name: aws.String("email"), Value: aws.String(userEmail)}},
	})
	if err != nil {
		var userExists *types.UsernameExistsException
		if errors.As(err, &userExists) {
			log.Printf("User %v already exists in the user pool.", userName)
			err = nil
		} else {
			log.Printf("Couldn't create user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}



// AdminSetUserPassword uses administrator credentials to set a password for a user without requiring a
// temporary password.
func (actor CognitoActions) AdminSetUserPassword(ctx context.Context, userPoolId string, userName string, password string) error {
	_, err := actor.CognitoClient.AdminSetUserPassword(ctx, &cognitoidentityprovider.AdminSetUserPasswordInput{
		Password:   aws.String(password),
		UserPoolId: aws.String(userPoolId),
		Username:   aws.String(userName),
		Permanent:  true,
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't set password for user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}
```
Create a struct that wraps DynamoDB actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)

// DynamoActions encapsulates the Amazon Simple Notification Service (Amazon SNS) actions
// used in the examples.
type DynamoActions struct {
	DynamoClient *dynamodb.Client
}

// User defines structured user data.
type User struct {
	UserName  string
	UserEmail string
	LastLogin *LoginInfo `dynamodbav:",omitempty"`
}

// LoginInfo defines structured custom login data.
type LoginInfo struct {
	UserPoolId string
	ClientId   string
	Time       string
}

// UserList defines a list of users.
type UserList struct {
	Users []User
}

// UserNameList returns the usernames contained in a UserList as a list of strings.
func (users *UserList) UserNameList() []string {
	names := make([]string, len(users.Users))
	for i := 0; i < len(users.Users); i++ {
		names[i] = users.Users[i].UserName
	}
	return names
}

// PopulateTable adds a set of test users to the table.
func (actor DynamoActions) PopulateTable(ctx context.Context, tableName string) error {
	var err error
	var item map[string]types.AttributeValue
	var writeReqs []types.WriteRequest
	for i := 1; i < 4; i++ {
		item, err = attributevalue.MarshalMap(User{UserName: fmt.Sprintf("test_user_%v", i), UserEmail: fmt.Sprintf("test_email_%v@example.com", i)})
		if err != nil {
			log.Printf("Couldn't marshall user into DynamoDB format. Here's why: %v\n", err)
			return err
		}
		writeReqs = append(writeReqs, types.WriteRequest{PutRequest: &types.PutRequest{Item: item}})
	}
	_, err = actor.DynamoClient.BatchWriteItem(ctx, &dynamodb.BatchWriteItemInput{
		RequestItems: map[string][]types.WriteRequest{tableName: writeReqs},
	})
	if err != nil {
		log.Printf("Couldn't populate table %v with users. Here's why: %v\n", tableName, err)
	}
	return err
}

// Scan scans the table for all items.
func (actor DynamoActions) Scan(ctx context.Context, tableName string) (UserList, error) {
	var userList UserList
	output, err := actor.DynamoClient.Scan(ctx, &dynamodb.ScanInput{
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't scan table %v for items. Here's why: %v\n", tableName, err)
	} else {
		err = attributevalue.UnmarshalListOfMaps(output.Items, &userList.Users)
		if err != nil {
			log.Printf("Couldn't unmarshal items into users. Here's why: %v\n", err)
		}
	}
	return userList, err
}

// AddUser adds a user item to a table.
func (actor DynamoActions) AddUser(ctx context.Context, tableName string, user User) error {
	userItem, err := attributevalue.MarshalMap(user)
	if err != nil {
		log.Printf("Couldn't marshall user to item. Here's why: %v\n", err)
	}
	_, err = actor.DynamoClient.PutItem(ctx, &dynamodb.PutItemInput{
		Item:      userItem,
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't put item in table %v. Here's why: %v", tableName, err)
	}
	return err
}
```
Create a struct that wraps CloudWatch Logs actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs/types"
)

type CloudWatchLogsActions struct {
	CwlClient *cloudwatchlogs.Client
}

// GetLatestLogStream gets the most recent log stream for a Lambda function.
func (actor CloudWatchLogsActions) GetLatestLogStream(ctx context.Context, functionName string) (types.LogStream, error) {
	var logStream types.LogStream
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.DescribeLogStreams(ctx, &cloudwatchlogs.DescribeLogStreamsInput{
		Descending:   aws.Bool(true),
		Limit:        aws.Int32(1),
		LogGroupName: aws.String(logGroupName),
		OrderBy:      types.OrderByLastEventTime,
	})
	if err != nil {
		log.Printf("Couldn't get log streams for log group %v. Here's why: %v\n", logGroupName, err)
	} else {
		logStream = output.LogStreams[0]
	}
	return logStream, err
}

// GetLogEvents gets the most recent eventCount events from the specified log stream.
func (actor CloudWatchLogsActions) GetLogEvents(ctx context.Context, functionName string, logStreamName string, eventCount int32) (
	[]types.OutputLogEvent, error) {
	var events []types.OutputLogEvent
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.GetLogEvents(ctx, &cloudwatchlogs.GetLogEventsInput{
		LogStreamName: aws.String(logStreamName),
		Limit:         aws.Int32(eventCount),
		LogGroupName:  aws.String(logGroupName),
	})
	if err != nil {
		log.Printf("Couldn't get log event for log stream %v. Here's why: %v\n", logStreamName, err)
	} else {
		events = output.Events
	}
	return events, err
}
```
Create a struct that wraps CloudFormation actions.  

```
import (
	"context"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
)

// StackOutputs defines a map of outputs from a specific stack.
type StackOutputs map[string]string

type CloudFormationActions struct {
	CfnClient *cloudformation.Client
}

// GetOutputs gets the outputs from a CloudFormation stack and puts them into a structured format.
func (actor CloudFormationActions) GetOutputs(ctx context.Context, stackName string) StackOutputs {
	output, err := actor.CfnClient.DescribeStacks(ctx, &cloudformation.DescribeStacksInput{
		StackName: aws.String(stackName),
	})
	if err != nil || len(output.Stacks) == 0 {
		log.Panicf("Couldn't find a CloudFormation stack named %v. Here's why: %v\n", stackName, err)
	}
	stackOutputs := StackOutputs{}
	for _, out := range output.Stacks[0].Outputs {
		stackOutputs[*out.OutputKey] = *out.OutputValue
	}
	return stackOutputs
}
```
Clean up resources.  

```
import (
	"context"
	"log"
	"user_pools_and_lambda_triggers/actions"

	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// Resources keeps track of AWS resources created during an example and handles
// cleanup when the example finishes.
type Resources struct {
	userPoolId       string
	userAccessTokens []string
	triggers         []actions.Trigger

	cognitoActor *actions.CognitoActions
	questioner   demotools.IQuestioner
}

func (resources *Resources) init(cognitoActor *actions.CognitoActions, questioner demotools.IQuestioner) {
	resources.userAccessTokens = []string{}
	resources.triggers = []actions.Trigger{}
	resources.cognitoActor = cognitoActor
	resources.questioner = questioner
}

// Cleanup deletes all AWS resources created during an example.
func (resources *Resources) Cleanup(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("Something went wrong during cleanup.\n%v\n", r)
			log.Println("Use the AWS Management Console to remove any remaining resources \n" +
				"that were created for this scenario.")
		}
	}()

	wantDelete := resources.questioner.AskBool("Do you want to remove all of the AWS resources that were created "+
		"during this demo (y/n)?", "y")
	if wantDelete {
		for _, accessToken := range resources.userAccessTokens {
			err := resources.cognitoActor.DeleteUser(ctx, accessToken)
			if err != nil {
				log.Println("Couldn't delete user during cleanup.")
				panic(err)
			}
			log.Println("Deleted user.")
		}
		triggerList := make([]actions.TriggerInfo, len(resources.triggers))
		for i := 0; i < len(resources.triggers); i++ {
			triggerList[i] = actions.TriggerInfo{Trigger: resources.triggers[i], HandlerArn: nil}
		}
		err := resources.cognitoActor.UpdateTriggers(ctx, resources.userPoolId, triggerList...)
		if err != nil {
			log.Println("Couldn't update Cognito triggers during cleanup.")
			panic(err)
		}
		log.Println("Removed Cognito triggers from user pool.")
	} else {
		log.Println("Be sure to remove resources when you're done with them to avoid unexpected charges!")
	}
}
```
+ For API details, see the following topics in *AWS SDK for Go API Reference*.
  + [DeleteUser](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.DeleteUser)
  + [InitiateAuth](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.InitiateAuth)
  + [SignUp](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.SignUp)
  + [UpdateUserPool](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.UpdateUserPool)

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/wkflw-pools-triggers#code-examples). 
Configure an interactive "Scenario" run. The JavaScript (v3) examples share a Scenario runner to streamline complex examples. The complete source code is on GitHub.   

```
import { AutoConfirm } from "./scenario-auto-confirm.js";

/**
 * The context is passed to every scenario. Scenario steps
 * will modify the context.
 */
const context = {
  errors: [],
  users: [
    {
      UserName: "test_user_1",
      UserEmail: "test_email_1@example.com",
    },
    {
      UserName: "test_user_2",
      UserEmail: "test_email_2@example.com",
    },
    {
      UserName: "test_user_3",
      UserEmail: "test_email_3@example.com",
    },
  ],
};

/**
 * Three Scenarios are created for the workflow. A Scenario is an orchestration class
 * that simplifies running a series of steps.
 */
export const scenarios = {
  // Demonstrate automatically confirming known users in a database.
  "auto-confirm": AutoConfirm(context),
};

// Call function if run directly
import { fileURLToPath } from "node:url";
import { parseScenarioArgs } from "@aws-doc-sdk-examples/lib/scenario/index.js";

if (process.argv[1] === fileURLToPath(import.meta.url)) {
  parseScenarioArgs(scenarios, {
    name: "Cognito user pools and triggers",
    description:
      "Demonstrate how to use the AWS SDKs to customize Amazon Cognito authentication behavior.",
  });
}
```
This Scenario demonstrates auto-confirming a known user. It orchestrates the example steps.   

```
import { wait } from "@aws-doc-sdk-examples/lib/utils/util-timers.js";
import {
  Scenario,
  ScenarioAction,
  ScenarioInput,
  ScenarioOutput,
} from "@aws-doc-sdk-examples/lib/scenario/scenario.js";

import {
  getStackOutputs,
  logCleanUpReminder,
  promptForStackName,
  promptForStackRegion,
  skipWhenErrors,
} from "./steps-common.js";
import { populateTable } from "./actions/dynamodb-actions.js";
import {
  addPreSignUpHandler,
  deleteUser,
  getUser,
  signIn,
  signUpUser,
} from "./actions/cognito-actions.js";
import {
  getLatestLogStreamForLambda,
  getLogEvents,
} from "./actions/cloudwatch-logs-actions.js";

/**
 * @typedef {{
 *   errors: Error[],
 *   password: string,
 *   users: { UserName: string, UserEmail: string }[],
 *   selectedUser?: string,
 *   stackName?: string,
 *   stackRegion?: string,
 *   token?: string,
 *   confirmDeleteSignedInUser?: boolean,
 *   TableName?: string,
 *   UserPoolClientId?: string,
 *   UserPoolId?: string,
 *   UserPoolArn?: string,
 *   AutoConfirmHandlerArn?: string,
 *   AutoConfirmHandlerName?: string
 * }} State
 */

const greeting = new ScenarioOutput(
  "greeting",
  (/** @type {State} */ state) => `This demo will populate some users into the \
database created as part of the "${state.stackName}" stack. \
Then the AutoConfirmHandler will be linked to the PreSignUp \
trigger from Cognito. Finally, you will choose a user to sign up.`,
  { skipWhen: skipWhenErrors },
);

const logPopulatingUsers = new ScenarioOutput(
  "logPopulatingUsers",
  "Populating the DynamoDB table with some users.",
  { skipWhenErrors: skipWhenErrors },
);

const logPopulatingUsersComplete = new ScenarioOutput(
  "logPopulatingUsersComplete",
  "Done populating users.",
  { skipWhen: skipWhenErrors },
);

const populateUsers = new ScenarioAction(
  "populateUsers",
  async (/** @type {State} */ state) => {
    const [_, err] = await populateTable({
      region: state.stackRegion,
      tableName: state.TableName,
      items: state.users,
    });
    if (err) {
      state.errors.push(err);
    }
  },
  {
    skipWhen: skipWhenErrors,
  },
);

const logSetupSignUpTrigger = new ScenarioOutput(
  "logSetupSignUpTrigger",
  "Setting up the PreSignUp trigger for the Cognito User Pool.",
  { skipWhen: skipWhenErrors },
);

const setupSignUpTrigger = new ScenarioAction(
  "setupSignUpTrigger",
  async (/** @type {State} */ state) => {
    const [_, err] = await addPreSignUpHandler({
      region: state.stackRegion,
      userPoolId: state.UserPoolId,
      handlerArn: state.AutoConfirmHandlerArn,
    });
    if (err) {
      state.errors.push(err);
    }
  },
  {
    skipWhen: skipWhenErrors,
  },
);

const logSetupSignUpTriggerComplete = new ScenarioOutput(
  "logSetupSignUpTriggerComplete",
  (
    /** @type {State} */ state,
  ) => `The lambda function "${state.AutoConfirmHandlerName}" \
has been configured as the PreSignUp trigger handler for the user pool "${state.UserPoolId}".`,
  { skipWhen: skipWhenErrors },
);

const selectUser = new ScenarioInput(
  "selectedUser",
  "Select a user to sign up.",
  {
    type: "select",
    choices: (/** @type {State} */ state) => state.users.map((u) => u.UserName),
    skipWhen: skipWhenErrors,
    default: (/** @type {State} */ state) => state.users[0].UserName,
  },
);

const checkIfUserAlreadyExists = new ScenarioAction(
  "checkIfUserAlreadyExists",
  async (/** @type {State} */ state) => {
    const [user, err] = await getUser({
      region: state.stackRegion,
      userPoolId: state.UserPoolId,
      username: state.selectedUser,
    });

    if (err?.name === "UserNotFoundException") {
      // Do nothing. We're not expecting the user to exist before
      // sign up is complete.
      return;
    }

    if (err) {
      state.errors.push(err);
      return;
    }

    if (user) {
      state.errors.push(
        new Error(
          `The user "${state.selectedUser}" already exists in the user pool "${state.UserPoolId}".`,
        ),
      );
    }
  },
  {
    skipWhen: skipWhenErrors,
  },
);

const createPassword = new ScenarioInput(
  "password",
  "Enter a password that has at least eight characters, uppercase, lowercase, numbers and symbols.",
  { type: "password", skipWhen: skipWhenErrors, default: "Abcd1234!" },
);

const logSignUpExistingUser = new ScenarioOutput(
  "logSignUpExistingUser",
  (/** @type {State} */ state) => `Signing up user "${state.selectedUser}".`,
  { skipWhen: skipWhenErrors },
);

const signUpExistingUser = new ScenarioAction(
  "signUpExistingUser",
  async (/** @type {State} */ state) => {
    const signUp = (password) =>
      signUpUser({
        region: state.stackRegion,
        userPoolClientId: state.UserPoolClientId,
        username: state.selectedUser,
        email: state.users.find((u) => u.UserName === state.selectedUser)
          .UserEmail,
        password,
      });

    let [_, err] = await signUp(state.password);

    while (err?.name === "InvalidPasswordException") {
      console.warn("The password you entered was invalid.");
      await createPassword.handle(state);
      [_, err] = await signUp(state.password);
    }

    if (err) {
      state.errors.push(err);
    }
  },
  { skipWhen: skipWhenErrors },
);

const logSignUpExistingUserComplete = new ScenarioOutput(
  "logSignUpExistingUserComplete",
  (/** @type {State} */ state) =>
    `"${state.selectedUser} was signed up successfully.`,
  { skipWhen: skipWhenErrors },
);

const logLambdaLogs = new ScenarioAction(
  "logLambdaLogs",
  async (/** @type {State} */ state) => {
    console.log(
      "Waiting a few seconds to let Lambda write to CloudWatch Logs...\n",
    );
    await wait(10);

    const [logStream, logStreamErr] = await getLatestLogStreamForLambda({
      functionName: state.AutoConfirmHandlerName,
      region: state.stackRegion,
    });
    if (logStreamErr) {
      state.errors.push(logStreamErr);
      return;
    }

    console.log(
      `Getting some recent events from log stream "${logStream.logStreamName}"`,
    );
    const [logEvents, logEventsErr] = await getLogEvents({
      functionName: state.AutoConfirmHandlerName,
      region: state.stackRegion,
      eventCount: 10,
      logStreamName: logStream.logStreamName,
    });
    if (logEventsErr) {
      state.errors.push(logEventsErr);
      return;
    }

    console.log(logEvents.map((ev) => `\t${ev.message}`).join(""));
  },
  { skipWhen: skipWhenErrors },
);

const logSignInUser = new ScenarioOutput(
  "logSignInUser",
  (/** @type {State} */ state) => `Let's sign in as ${state.selectedUser}`,
  { skipWhen: skipWhenErrors },
);

const signInUser = new ScenarioAction(
  "signInUser",
  async (/** @type {State} */ state) => {
    const [response, err] = await signIn({
      region: state.stackRegion,
      clientId: state.UserPoolClientId,
      username: state.selectedUser,
      password: state.password,
    });

    if (err?.name === "PasswordResetRequiredException") {
      state.errors.push(new Error("Please reset your password."));
      return;
    }

    if (err) {
      state.errors.push(err);
      return;
    }

    state.token = response?.AuthenticationResult?.AccessToken;
  },
  { skipWhen: skipWhenErrors },
);

const logSignInUserComplete = new ScenarioOutput(
  "logSignInUserComplete",
  (/** @type {State} */ state) =>
    `Successfully signed in. Your access token starts with: ${state.token.slice(0, 11)}`,
  { skipWhen: skipWhenErrors },
);

const confirmDeleteSignedInUser = new ScenarioInput(
  "confirmDeleteSignedInUser",
  "Do you want to delete the currently signed in user?",
  { type: "confirm", skipWhen: skipWhenErrors },
);

const deleteSignedInUser = new ScenarioAction(
  "deleteSignedInUser",
  async (/** @type {State} */ state) => {
    const [_, err] = await deleteUser({
      region: state.stackRegion,
      accessToken: state.token,
    });

    if (err) {
      state.errors.push(err);
    }
  },
  {
    skipWhen: (/** @type {State} */ state) =>
      skipWhenErrors(state) || !state.confirmDeleteSignedInUser,
  },
);

const logErrors = new ScenarioOutput(
  "logErrors",
  (/** @type {State}*/ state) => {
    const errorList = state.errors
      .map((err) => ` - ${err.name}: ${err.message}`)
      .join("\n");
    return `Scenario errors found:\n${errorList}`;
  },
  {
    // Don't log errors when there aren't any!
    skipWhen: (/** @type {State} */ state) => state.errors.length === 0,
  },
);

export const AutoConfirm = (context) =>
  new Scenario(
    "AutoConfirm",
    [
      promptForStackName,
      promptForStackRegion,
      getStackOutputs,
      greeting,
      logPopulatingUsers,
      populateUsers,
      logPopulatingUsersComplete,
      logSetupSignUpTrigger,
      setupSignUpTrigger,
      logSetupSignUpTriggerComplete,
      selectUser,
      checkIfUserAlreadyExists,
      createPassword,
      logSignUpExistingUser,
      signUpExistingUser,
      logSignUpExistingUserComplete,
      logLambdaLogs,
      logSignInUser,
      signInUser,
      logSignInUserComplete,
      confirmDeleteSignedInUser,
      deleteSignedInUser,
      logCleanUpReminder,
      logErrors,
    ],
    context,
  );
```
These are steps that are shared with other Scenarios.  

```
import {
  ScenarioAction,
  ScenarioInput,
  ScenarioOutput,
} from "@aws-doc-sdk-examples/lib/scenario/scenario.js";
import { getCfnOutputs } from "@aws-doc-sdk-examples/lib/sdk/cfn-outputs.js";

export const skipWhenErrors = (state) => state.errors.length > 0;

export const getStackOutputs = new ScenarioAction(
  "getStackOutputs",
  async (state) => {
    if (!state.stackName || !state.stackRegion) {
      state.errors.push(
        new Error(
          "No stack name or region provided. The stack name and \
region are required to fetch CFN outputs relevant to this example.",
        ),
      );
      return;
    }

    const outputs = await getCfnOutputs(state.stackName, state.stackRegion);
    Object.assign(state, outputs);
  },
);

export const promptForStackName = new ScenarioInput(
  "stackName",
  "Enter the name of the stack you deployed earlier.",
  { type: "input", default: "PoolsAndTriggersStack" },
);

export const promptForStackRegion = new ScenarioInput(
  "stackRegion",
  "Enter the region of the stack you deployed earlier.",
  { type: "input", default: "us-east-1" },
);

export const logCleanUpReminder = new ScenarioOutput(
  "logCleanUpReminder",
  "All done. Remember to run 'cdk destroy' to teardown the stack.",
  { skipWhen: skipWhenErrors },
);
```
A handler for the `PreSignUp` trigger with a Lambda function.  

```
import type { PreSignUpTriggerEvent, Handler } from "aws-lambda";
import type { UserRepository } from "./user-repository";
import { DynamoDBUserRepository } from "./user-repository";

export class PreSignUpHandler {
  private userRepository: UserRepository;

  constructor(userRepository: UserRepository) {
    this.userRepository = userRepository;
  }

  private isPreSignUpTriggerSource(event: PreSignUpTriggerEvent): boolean {
    return event.triggerSource === "PreSignUp_SignUp";
  }

  private getEventUserEmail(event: PreSignUpTriggerEvent): string {
    return event.request.userAttributes.email;
  }

  async handlePreSignUpTriggerEvent(
    event: PreSignUpTriggerEvent,
  ): Promise<PreSignUpTriggerEvent> {
    console.log(
      `Received presignup from ${event.triggerSource} for user '${event.userName}'`,
    );

    if (!this.isPreSignUpTriggerSource(event)) {
      return event;
    }

    const eventEmail = this.getEventUserEmail(event);
    console.log(`Looking up email ${eventEmail}.`);
    const storedUserInfo =
      await this.userRepository.getUserInfoByEmail(eventEmail);

    if (!storedUserInfo) {
      console.log(
        `Email ${eventEmail} not found. Email verification is required.`,
      );
      return event;
    }

    if (storedUserInfo.UserName !== event.userName) {
      console.log(
        `UserEmail ${eventEmail} found, but stored UserName '${storedUserInfo.UserName}' does not match supplied UserName '${event.userName}'. Verification is required.`,
      );
    } else {
      console.log(
        `UserEmail ${eventEmail} found with matching UserName ${storedUserInfo.UserName}. User is confirmed.`,
      );
      event.response.autoConfirmUser = true;
      event.response.autoVerifyEmail = true;
    }
    return event;
  }
}

const createPreSignUpHandler = (): PreSignUpHandler => {
  const tableName = process.env.TABLE_NAME;
  if (!tableName) {
    throw new Error("TABLE_NAME environment variable is not set");
  }

  const userRepository = new DynamoDBUserRepository(tableName);
  return new PreSignUpHandler(userRepository);
};

export const handler: Handler = async (event: PreSignUpTriggerEvent) => {
  const preSignUpHandler = createPreSignUpHandler();
  return preSignUpHandler.handlePreSignUpTriggerEvent(event);
};
```
Module of CloudWatch Logs actions.  

```
import {
  CloudWatchLogsClient,
  GetLogEventsCommand,
  OrderBy,
  paginateDescribeLogStreams,
} from "@aws-sdk/client-cloudwatch-logs";

/**
 * Get the latest log stream for a Lambda function.
 * @param {{ functionName: string, region: string }} config
 * @returns {Promise<[import("@aws-sdk/client-cloudwatch-logs").LogStream | null, unknown]>}
 */
export const getLatestLogStreamForLambda = async ({ functionName, region }) => {
  try {
    const logGroupName = `/aws/lambda/${functionName}`;
    const cwlClient = new CloudWatchLogsClient({ region });
    const paginator = paginateDescribeLogStreams(
      { client: cwlClient },
      {
        descending: true,
        limit: 1,
        orderBy: OrderBy.LastEventTime,
        logGroupName,
      },
    );

    for await (const page of paginator) {
      return [page.logStreams[0], null];
    }
  } catch (err) {
    return [null, err];
  }
};

/**
 * Get the log events for a Lambda function's log stream.
 * @param {{
 *   functionName: string,
 *   logStreamName: string,
 *   eventCount: number,
 *   region: string
 * }} config
 * @returns {Promise<[import("@aws-sdk/client-cloudwatch-logs").OutputLogEvent[] | null, unknown]>}
 */
export const getLogEvents = async ({
  functionName,
  logStreamName,
  eventCount,
  region,
}) => {
  try {
    const cwlClient = new CloudWatchLogsClient({ region });
    const logGroupName = `/aws/lambda/${functionName}`;
    const response = await cwlClient.send(
      new GetLogEventsCommand({
        logStreamName: logStreamName,
        limit: eventCount,
        logGroupName: logGroupName,
      }),
    );

    return [response.events, null];
  } catch (err) {
    return [null, err];
  }
};
```
Module of Amazon Cognito actions.  

```
import {
  AdminGetUserCommand,
  CognitoIdentityProviderClient,
  DeleteUserCommand,
  InitiateAuthCommand,
  SignUpCommand,
  UpdateUserPoolCommand,
} from "@aws-sdk/client-cognito-identity-provider";

/**
 * Connect a Lambda function to the PreSignUp trigger for a Cognito user pool
 * @param {{ region: string, userPoolId: string, handlerArn: string }} config
 * @returns {Promise<[import("@aws-sdk/client-cognito-identity-provider").UpdateUserPoolCommandOutput | null, unknown]>}
 */
export const addPreSignUpHandler = async ({
  region,
  userPoolId,
  handlerArn,
}) => {
  try {
    const cognitoClient = new CognitoIdentityProviderClient({
      region,
    });

    const command = new UpdateUserPoolCommand({
      UserPoolId: userPoolId,
      LambdaConfig: {
        PreSignUp: handlerArn,
      },
    });

    const response = await cognitoClient.send(command);
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};

/**
 * Attempt to register a user to a user pool with a given username and password.
 * @param {{
 *   region: string,
 *   userPoolClientId: string,
 *   username: string,
 *   email: string,
 *   password: string
 * }} config
 * @returns {Promise<[import("@aws-sdk/client-cognito-identity-provider").SignUpCommandOutput | null, unknown]>}
 */
export const signUpUser = async ({
  region,
  userPoolClientId,
  username,
  email,
  password,
}) => {
  try {
    const cognitoClient = new CognitoIdentityProviderClient({
      region,
    });

    const response = await cognitoClient.send(
      new SignUpCommand({
        ClientId: userPoolClientId,
        Username: username,
        Password: password,
        UserAttributes: [{ Name: "email", Value: email }],
      }),
    );
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};

/**
 * Sign in a user to Amazon Cognito using a username and password authentication flow.
 * @param {{ region: string, clientId: string, username: string, password: string }} config
 * @returns {Promise<[import("@aws-sdk/client-cognito-identity-provider").InitiateAuthCommandOutput | null, unknown]>}
 */
export const signIn = async ({ region, clientId, username, password }) => {
  try {
    const cognitoClient = new CognitoIdentityProviderClient({ region });
    const response = await cognitoClient.send(
      new InitiateAuthCommand({
        AuthFlow: "USER_PASSWORD_AUTH",
        ClientId: clientId,
        AuthParameters: { USERNAME: username, PASSWORD: password },
      }),
    );
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};

/**
 * Retrieve an existing user from a user pool.
 * @param {{ region: string, userPoolId: string, username: string }} config
 * @returns {Promise<[import("@aws-sdk/client-cognito-identity-provider").AdminGetUserCommandOutput | null, unknown]>}
 */
export const getUser = async ({ region, userPoolId, username }) => {
  try {
    const cognitoClient = new CognitoIdentityProviderClient({ region });
    const response = await cognitoClient.send(
      new AdminGetUserCommand({
        UserPoolId: userPoolId,
        Username: username,
      }),
    );
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};

/**
 * Delete the signed-in user. Useful for allowing a user to delete their
 * own profile.
 * @param {{ region: string, accessToken: string }} config
 * @returns {Promise<[import("@aws-sdk/client-cognito-identity-provider").DeleteUserCommandOutput | null, unknown]>}
 */
export const deleteUser = async ({ region, accessToken }) => {
  try {
    const client = new CognitoIdentityProviderClient({ region });
    const response = await client.send(
      new DeleteUserCommand({ AccessToken: accessToken }),
    );
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};
```
Module of DynamoDB actions.  

```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import {
  BatchWriteCommand,
  DynamoDBDocumentClient,
} from "@aws-sdk/lib-dynamodb";

/**
 * Populate a DynamoDB table with provide items.
 * @param {{ region: string, tableName: string, items: Record<string, unknown>[] }} config
 * @returns {Promise<[import("@aws-sdk/lib-dynamodb").BatchWriteCommandOutput | null, unknown]>}
 */
export const populateTable = async ({ region, tableName, items }) => {
  try {
    const ddbClient = new DynamoDBClient({ region });
    const docClient = DynamoDBDocumentClient.from(ddbClient);
    const response = await docClient.send(
      new BatchWriteCommand({
        RequestItems: {
          [tableName]: items.map((item) => ({
            PutRequest: {
              Item: item,
            },
          })),
        },
      }),
    );
    return [response, null];
  } catch (err) {
    return [null, err];
  }
};
```
+ For API details, see the following topics in *AWS SDK for JavaScript API Reference*.
  + [DeleteUser](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cognito-identity-provider/command/DeleteUserCommand)
  + [InitiateAuth](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cognito-identity-provider/command/InitiateAuthCommand)
  + [SignUp](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cognito-identity-provider/command/SignUpCommand)
  + [UpdateUserPool](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cognito-identity-provider/command/UpdateUserPoolCommand)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Automatically migrate known Amazon Cognito users with a Lambda function using an AWS SDK
<a name="example_cross_CognitoAutoMigrateUser_section"></a>

The following code example shows how to automatically migrate known Amazon Cognito users with a Lambda function.
+ Configure a user pool to call a Lambda function for the `MigrateUser` trigger.
+ Sign in to Amazon Cognito with a username and email that is not in the user pool.
+ The Lambda function scans a DynamoDB table and automatically migrates known users to the user pool.
+ Perform the forgot password flow to reset the password for the migrated user.
+ Sign in as the new user, then clean up resources.

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/workflows/user_pools_and_lambda_triggers#code-examples). 
Run an interactive scenario at a command prompt.  

```
import (
	"context"
	"errors"
	"fmt"
	"log"
	"strings"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// MigrateUser separates the steps of this scenario into individual functions so that
// they are simpler to read and understand.
type MigrateUser struct {
	helper       IScenarioHelper
	questioner   demotools.IQuestioner
	resources    Resources
	cognitoActor *actions.CognitoActions
}

// NewMigrateUser constructs a new migrate user runner.
func NewMigrateUser(sdkConfig aws.Config, questioner demotools.IQuestioner, helper IScenarioHelper) MigrateUser {
	scenario := MigrateUser{
		helper:       helper,
		questioner:   questioner,
		resources:    Resources{},
		cognitoActor: &actions.CognitoActions{CognitoClient: cognitoidentityprovider.NewFromConfig(sdkConfig)},
	}
	scenario.resources.init(scenario.cognitoActor, questioner)
	return scenario
}

// AddMigrateUserTrigger adds a Lambda handler as an invocation target for the MigrateUser trigger.
func (runner *MigrateUser) AddMigrateUserTrigger(ctx context.Context, userPoolId string, functionArn string) {
	log.Printf("Let's add a Lambda function to handle the MigrateUser trigger from Cognito.\n" +
		"This trigger happens when an unknown user signs in, and lets your function take action before Cognito\n" +
		"rejects the user.\n\n")
	err := runner.cognitoActor.UpdateTriggers(
		ctx, userPoolId,
		actions.TriggerInfo{Trigger: actions.UserMigration, HandlerArn: aws.String(functionArn)})
	if err != nil {
		panic(err)
	}
	log.Printf("Lambda function %v added to user pool %v to handle the MigrateUser trigger.\n",
		functionArn, userPoolId)

	log.Println(strings.Repeat("-", 88))
}

// SignInUser adds a new user to the known users table and signs that user in to Amazon Cognito.
func (runner *MigrateUser) SignInUser(ctx context.Context, usersTable string, clientId string) (bool, actions.User) {
	log.Println("Let's sign in a user to your Cognito user pool. When the username and email matches an entry in the\n" +
		"DynamoDB known users table, the email is automatically verified and the user is migrated to the Cognito user pool.")

	user := actions.User{}
	user.UserName = runner.questioner.Ask("\nEnter a username:")
	user.UserEmail = runner.questioner.Ask("\nEnter an email that you own. This email will be used to confirm user migration\n" +
		"during this example:")

	runner.helper.AddKnownUser(ctx, usersTable, user)

	var err error
	var resetRequired *types.PasswordResetRequiredException
	var authResult *types.AuthenticationResultType
	signedIn := false
	for !signedIn && resetRequired == nil {
		log.Printf("Signing in to Cognito as user '%v'. The expected result is a PasswordResetRequiredException.\n\n", user.UserName)
		authResult, err = runner.cognitoActor.SignIn(ctx, clientId, user.UserName, "_")
		if err != nil {
			if errors.As(err, &resetRequired) {
				log.Printf("\nUser '%v' is not in the Cognito user pool but was found in the DynamoDB known users table.\n"+
					"User migration is started and a password reset is required.", user.UserName)
			} else {
				panic(err)
			}
		} else {
			log.Printf("User '%v' successfully signed in. This is unexpected and probably means you have not\n"+
				"cleaned up a previous run of this scenario, so the user exist in the Cognito user pool.\n"+
				"You can continue this example and select to clean up resources, or manually remove\n"+
				"the user from your user pool and try again.", user.UserName)
			runner.resources.userAccessTokens = append(runner.resources.userAccessTokens, *authResult.AccessToken)
			signedIn = true
		}
	}

	log.Println(strings.Repeat("-", 88))
	return resetRequired != nil, user
}

// ResetPassword starts a password recovery flow.
func (runner *MigrateUser) ResetPassword(ctx context.Context, clientId string, user actions.User) {
	wantCode := runner.questioner.AskBool(fmt.Sprintf("In order to migrate the user to Cognito, you must be able to receive a confirmation\n"+
		"code by email at %v. Do you want to send a code (y/n)?", user.UserEmail), "y")
	if !wantCode {
		log.Println("To complete this example and successfully migrate a user to Cognito, you must enter an email\n" +
			"you own that can receive a confirmation code.")
		return
	}
	codeDelivery, err := runner.cognitoActor.ForgotPassword(ctx, clientId, user.UserName)
	if err != nil {
		panic(err)
	}
	log.Printf("\nA confirmation code has been sent to %v.", *codeDelivery.Destination)
	code := runner.questioner.Ask("Check your email and enter it here:")

	confirmed := false
	password := runner.questioner.AskPassword("\nEnter a password that has at least eight characters, uppercase, lowercase, numbers and symbols.\n"+
		"(the password will not display as you type):", 8)
	for !confirmed {
		log.Printf("\nConfirming password reset for user '%v'.\n", user.UserName)
		err = runner.cognitoActor.ConfirmForgotPassword(ctx, clientId, code, user.UserName, password)
		if err != nil {
			var invalidPassword *types.InvalidPasswordException
			if errors.As(err, &invalidPassword) {
				password = runner.questioner.AskPassword("\nEnter another password:", 8)
			} else {
				panic(err)
			}
		} else {
			confirmed = true
		}
	}
	log.Printf("User '%v' successfully confirmed and migrated.\n", user.UserName)
	log.Println("Signing in with your username and password...")
	authResult, err := runner.cognitoActor.SignIn(ctx, clientId, user.UserName, password)
	if err != nil {
		panic(err)
	}
	log.Printf("Successfully signed in. Your access token starts with: %v...\n", (*authResult.AccessToken)[:10])
	runner.resources.userAccessTokens = append(runner.resources.userAccessTokens, *authResult.AccessToken)

	log.Println(strings.Repeat("-", 88))
}

// Run runs the scenario.
func (runner *MigrateUser) Run(ctx context.Context, stackName string) {
	defer func() {
		if r := recover(); r != nil {
			log.Println("Something went wrong with the demo.")
			runner.resources.Cleanup(ctx)
		}
	}()

	log.Println(strings.Repeat("-", 88))
	log.Printf("Welcome\n")

	log.Println(strings.Repeat("-", 88))

	stackOutputs, err := runner.helper.GetStackOutputs(ctx, stackName)
	if err != nil {
		panic(err)
	}
	runner.resources.userPoolId = stackOutputs["UserPoolId"]

	runner.AddMigrateUserTrigger(ctx, stackOutputs["UserPoolId"], stackOutputs["MigrateUserFunctionArn"])
	runner.resources.triggers = append(runner.resources.triggers, actions.UserMigration)
	resetNeeded, user := runner.SignInUser(ctx, stackOutputs["TableName"], stackOutputs["UserPoolClientId"])
	if resetNeeded {
		runner.helper.ListRecentLogEvents(ctx, stackOutputs["MigrateUserFunction"])
		runner.ResetPassword(ctx, stackOutputs["UserPoolClientId"], user)
	}

	runner.resources.Cleanup(ctx)

	log.Println(strings.Repeat("-", 88))
	log.Println("Thanks for watching!")
	log.Println(strings.Repeat("-", 88))
}
```
Handle the `MigrateUser` trigger with a Lambda function.  

```
import (
	"context"
	"log"
	"os"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
)

const TABLE_NAME = "TABLE_NAME"

// UserInfo defines structured user data that can be marshalled to a DynamoDB format.
type UserInfo struct {
	UserName  string `dynamodbav:"UserName"`
	UserEmail string `dynamodbav:"UserEmail"`
}

type handler struct {
	dynamoClient *dynamodb.Client
}

// HandleRequest handles the MigrateUser event by looking up a user in an Amazon DynamoDB table and
// specifying whether they should be migrated to the user pool.
func (h *handler) HandleRequest(ctx context.Context, event events.CognitoEventUserPoolsMigrateUser) (events.CognitoEventUserPoolsMigrateUser, error) {
	log.Printf("Received migrate trigger from %v for user '%v'", event.TriggerSource, event.UserName)
	if event.TriggerSource != "UserMigration_Authentication" {
		return event, nil
	}
	tableName := os.Getenv(TABLE_NAME)
	user := UserInfo{
		UserName: event.UserName,
	}
	log.Printf("Looking up user '%v' in table %v.\n", user.UserName, tableName)
	filterEx := expression.Name("UserName").Equal(expression.Value(user.UserName))
	expr, err := expression.NewBuilder().WithFilter(filterEx).Build()
	if err != nil {
		log.Printf("Error building expression to query for user '%v'.\n", user.UserName)
		return event, err
	}
	output, err := h.dynamoClient.Scan(ctx, &dynamodb.ScanInput{
		TableName:                 aws.String(tableName),
		FilterExpression:          expr.Filter(),
		ExpressionAttributeNames:  expr.Names(),
		ExpressionAttributeValues: expr.Values(),
	})
	if err != nil {
		log.Printf("Error looking up user '%v'.\n", user.UserName)
		return event, err
	}
	if len(output.Items) == 0 {
		log.Printf("User '%v' not found, not migrating user.\n", user.UserName)
		return event, err
	}

	var users []UserInfo
	err = attributevalue.UnmarshalListOfMaps(output.Items, &users)
	if err != nil {
		log.Printf("Couldn't unmarshal DynamoDB items. Here's why: %v\n", err)
		return event, err
	}

	user = users[0]
	log.Printf("UserName '%v' found with email %v. User is migrated and must reset password.\n", user.UserName, user.UserEmail)
	event.CognitoEventUserPoolsMigrateUserResponse.UserAttributes = map[string]string{
		"email":          user.UserEmail,
		"email_verified": "true", // email_verified is required for the forgot password flow.
	}
	event.CognitoEventUserPoolsMigrateUserResponse.FinalUserStatus = "RESET_REQUIRED"
	event.CognitoEventUserPoolsMigrateUserResponse.MessageAction = "SUPPRESS"

	return event, err
}

func main() {
	ctx := context.Background()
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		log.Panicln(err)
	}
	h := handler{
		dynamoClient: dynamodb.NewFromConfig(sdkConfig),
	}
	lambda.Start(h.HandleRequest)
}
```
Create a struct that performs common tasks.  

```
import (
	"context"
	"log"
	"strings"
	"time"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// IScenarioHelper defines common functions used by the workflows in this example.
type IScenarioHelper interface {
	Pause(secs int)
	GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error)
	PopulateUserTable(ctx context.Context, tableName string)
	GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error)
	AddKnownUser(ctx context.Context, tableName string, user actions.User)
	ListRecentLogEvents(ctx context.Context, functionName string)
}

// ScenarioHelper contains AWS wrapper structs used by the workflows in this example.
type ScenarioHelper struct {
	questioner  demotools.IQuestioner
	dynamoActor *actions.DynamoActions
	cfnActor    *actions.CloudFormationActions
	cwlActor    *actions.CloudWatchLogsActions
	isTestRun   bool
}

// NewScenarioHelper constructs a new scenario helper.
func NewScenarioHelper(sdkConfig aws.Config, questioner demotools.IQuestioner) ScenarioHelper {
	scenario := ScenarioHelper{
		questioner:  questioner,
		dynamoActor: &actions.DynamoActions{DynamoClient: dynamodb.NewFromConfig(sdkConfig)},
		cfnActor:    &actions.CloudFormationActions{CfnClient: cloudformation.NewFromConfig(sdkConfig)},
		cwlActor:    &actions.CloudWatchLogsActions{CwlClient: cloudwatchlogs.NewFromConfig(sdkConfig)},
	}
	return scenario
}

// Pause waits for the specified number of seconds.
func (helper ScenarioHelper) Pause(secs int) {
	if !helper.isTestRun {
		time.Sleep(time.Duration(secs) * time.Second)
	}
}

// GetStackOutputs gets the outputs from the specified CloudFormation stack in a structured format.
func (helper ScenarioHelper) GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error) {
	return helper.cfnActor.GetOutputs(ctx, stackName), nil
}

// PopulateUserTable fills the known user table with example data.
func (helper ScenarioHelper) PopulateUserTable(ctx context.Context, tableName string) {
	log.Printf("First, let's add some users to the DynamoDB %v table we'll use for this example.\n", tableName)
	err := helper.dynamoActor.PopulateTable(ctx, tableName)
	if err != nil {
		panic(err)
	}
}

// GetKnownUsers gets the users from the known users table in a structured format.
func (helper ScenarioHelper) GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error) {
	knownUsers, err := helper.dynamoActor.Scan(ctx, tableName)
	if err != nil {
		log.Printf("Couldn't get known users from table %v. Here's why: %v\n", tableName, err)
	}
	return knownUsers, err
}

// AddKnownUser adds a user to the known users table.
func (helper ScenarioHelper) AddKnownUser(ctx context.Context, tableName string, user actions.User) {
	log.Printf("Adding user '%v' with email '%v' to the DynamoDB known users table...\n",
		user.UserName, user.UserEmail)
	err := helper.dynamoActor.AddUser(ctx, tableName, user)
	if err != nil {
		panic(err)
	}
}

// ListRecentLogEvents gets the most recent log stream and events for the specified Lambda function and displays them.
func (helper ScenarioHelper) ListRecentLogEvents(ctx context.Context, functionName string) {
	log.Println("Waiting a few seconds to let Lambda write to CloudWatch Logs...")
	helper.Pause(10)
	log.Println("Okay, let's check the logs to find what's happened recently with your Lambda function.")
	logStream, err := helper.cwlActor.GetLatestLogStream(ctx, functionName)
	if err != nil {
		panic(err)
	}
	log.Printf("Getting some recent events from log stream %v\n", *logStream.LogStreamName)
	events, err := helper.cwlActor.GetLogEvents(ctx, functionName, *logStream.LogStreamName, 10)
	if err != nil {
		panic(err)
	}
	for _, event := range events {
		log.Printf("\t%v", *event.Message)
	}
	log.Println(strings.Repeat("-", 88))
}
```
Create a struct that wraps Amazon Cognito actions.  

```
import (
	"context"
	"errors"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
)

type CognitoActions struct {
	CognitoClient *cognitoidentityprovider.Client
}



// Trigger and TriggerInfo define typed data for updating an Amazon Cognito trigger.
type Trigger int

const (
	PreSignUp Trigger = iota
	UserMigration
	PostAuthentication
)

type TriggerInfo struct {
	Trigger    Trigger
	HandlerArn *string
}

// UpdateTriggers adds or removes Lambda triggers for a user pool. When a trigger is specified with a `nil` value,
// it is removed from the user pool.
func (actor CognitoActions) UpdateTriggers(ctx context.Context, userPoolId string, triggers ...TriggerInfo) error {
	output, err := actor.CognitoClient.DescribeUserPool(ctx, &cognitoidentityprovider.DescribeUserPoolInput{
		UserPoolId: aws.String(userPoolId),
	})
	if err != nil {
		log.Printf("Couldn't get info about user pool %v. Here's why: %v\n", userPoolId, err)
		return err
	}
	lambdaConfig := output.UserPool.LambdaConfig
	for _, trigger := range triggers {
		switch trigger.Trigger {
		case PreSignUp:
			lambdaConfig.PreSignUp = trigger.HandlerArn
		case UserMigration:
			lambdaConfig.UserMigration = trigger.HandlerArn
		case PostAuthentication:
			lambdaConfig.PostAuthentication = trigger.HandlerArn
		}
	}
	_, err = actor.CognitoClient.UpdateUserPool(ctx, &cognitoidentityprovider.UpdateUserPoolInput{
		UserPoolId:   aws.String(userPoolId),
		LambdaConfig: lambdaConfig,
	})
	if err != nil {
		log.Printf("Couldn't update user pool %v. Here's why: %v\n", userPoolId, err)
	}
	return err
}



// SignUp signs up a user with Amazon Cognito.
func (actor CognitoActions) SignUp(ctx context.Context, clientId string, userName string, password string, userEmail string) (bool, error) {
	confirmed := false
	output, err := actor.CognitoClient.SignUp(ctx, &cognitoidentityprovider.SignUpInput{
		ClientId: aws.String(clientId),
		Password: aws.String(password),
		Username: aws.String(userName),
		UserAttributes: []types.AttributeType{
			{Name: aws.String("email"), Value: aws.String(userEmail)},
		},
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't sign up user %v. Here's why: %v\n", userName, err)
		}
	} else {
		confirmed = output.UserConfirmed
	}
	return confirmed, err
}



// SignIn signs in a user to Amazon Cognito using a username and password authentication flow.
func (actor CognitoActions) SignIn(ctx context.Context, clientId string, userName string, password string) (*types.AuthenticationResultType, error) {
	var authResult *types.AuthenticationResultType
	output, err := actor.CognitoClient.InitiateAuth(ctx, &cognitoidentityprovider.InitiateAuthInput{
		AuthFlow:       "USER_PASSWORD_AUTH",
		ClientId:       aws.String(clientId),
		AuthParameters: map[string]string{"USERNAME": userName, "PASSWORD": password},
	})
	if err != nil {
		var resetRequired *types.PasswordResetRequiredException
		if errors.As(err, &resetRequired) {
			log.Println(*resetRequired.Message)
		} else {
			log.Printf("Couldn't sign in user %v. Here's why: %v\n", userName, err)
		}
	} else {
		authResult = output.AuthenticationResult
	}
	return authResult, err
}



// ForgotPassword starts a password recovery flow for a user. This flow typically sends a confirmation code
// to the user's configured notification destination, such as email.
func (actor CognitoActions) ForgotPassword(ctx context.Context, clientId string, userName string) (*types.CodeDeliveryDetailsType, error) {
	output, err := actor.CognitoClient.ForgotPassword(ctx, &cognitoidentityprovider.ForgotPasswordInput{
		ClientId: aws.String(clientId),
		Username: aws.String(userName),
	})
	if err != nil {
		log.Printf("Couldn't start password reset for user '%v'. Here;s why: %v\n", userName, err)
	}
	return output.CodeDeliveryDetails, err
}



// ConfirmForgotPassword confirms a user with a confirmation code and a new password.
func (actor CognitoActions) ConfirmForgotPassword(ctx context.Context, clientId string, code string, userName string, password string) error {
	_, err := actor.CognitoClient.ConfirmForgotPassword(ctx, &cognitoidentityprovider.ConfirmForgotPasswordInput{
		ClientId:         aws.String(clientId),
		ConfirmationCode: aws.String(code),
		Password:         aws.String(password),
		Username:         aws.String(userName),
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't confirm user %v. Here's why: %v", userName, err)
		}
	}
	return err
}



// DeleteUser removes a user from the user pool.
func (actor CognitoActions) DeleteUser(ctx context.Context, userAccessToken string) error {
	_, err := actor.CognitoClient.DeleteUser(ctx, &cognitoidentityprovider.DeleteUserInput{
		AccessToken: aws.String(userAccessToken),
	})
	if err != nil {
		log.Printf("Couldn't delete user. Here's why: %v\n", err)
	}
	return err
}



// AdminCreateUser uses administrator credentials to add a user to a user pool. This method leaves the user
// in a state that requires they enter a new password next time they sign in.
func (actor CognitoActions) AdminCreateUser(ctx context.Context, userPoolId string, userName string, userEmail string) error {
	_, err := actor.CognitoClient.AdminCreateUser(ctx, &cognitoidentityprovider.AdminCreateUserInput{
		UserPoolId:     aws.String(userPoolId),
		Username:       aws.String(userName),
		MessageAction:  types.MessageActionTypeSuppress,
		UserAttributes: []types.AttributeType{{Name: aws.String("email"), Value: aws.String(userEmail)}},
	})
	if err != nil {
		var userExists *types.UsernameExistsException
		if errors.As(err, &userExists) {
			log.Printf("User %v already exists in the user pool.", userName)
			err = nil
		} else {
			log.Printf("Couldn't create user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}



// AdminSetUserPassword uses administrator credentials to set a password for a user without requiring a
// temporary password.
func (actor CognitoActions) AdminSetUserPassword(ctx context.Context, userPoolId string, userName string, password string) error {
	_, err := actor.CognitoClient.AdminSetUserPassword(ctx, &cognitoidentityprovider.AdminSetUserPasswordInput{
		Password:   aws.String(password),
		UserPoolId: aws.String(userPoolId),
		Username:   aws.String(userName),
		Permanent:  true,
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't set password for user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}
```
Create a struct that wraps DynamoDB actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)

// DynamoActions encapsulates the Amazon Simple Notification Service (Amazon SNS) actions
// used in the examples.
type DynamoActions struct {
	DynamoClient *dynamodb.Client
}

// User defines structured user data.
type User struct {
	UserName  string
	UserEmail string
	LastLogin *LoginInfo `dynamodbav:",omitempty"`
}

// LoginInfo defines structured custom login data.
type LoginInfo struct {
	UserPoolId string
	ClientId   string
	Time       string
}

// UserList defines a list of users.
type UserList struct {
	Users []User
}

// UserNameList returns the usernames contained in a UserList as a list of strings.
func (users *UserList) UserNameList() []string {
	names := make([]string, len(users.Users))
	for i := 0; i < len(users.Users); i++ {
		names[i] = users.Users[i].UserName
	}
	return names
}

// PopulateTable adds a set of test users to the table.
func (actor DynamoActions) PopulateTable(ctx context.Context, tableName string) error {
	var err error
	var item map[string]types.AttributeValue
	var writeReqs []types.WriteRequest
	for i := 1; i < 4; i++ {
		item, err = attributevalue.MarshalMap(User{UserName: fmt.Sprintf("test_user_%v", i), UserEmail: fmt.Sprintf("test_email_%v@example.com", i)})
		if err != nil {
			log.Printf("Couldn't marshall user into DynamoDB format. Here's why: %v\n", err)
			return err
		}
		writeReqs = append(writeReqs, types.WriteRequest{PutRequest: &types.PutRequest{Item: item}})
	}
	_, err = actor.DynamoClient.BatchWriteItem(ctx, &dynamodb.BatchWriteItemInput{
		RequestItems: map[string][]types.WriteRequest{tableName: writeReqs},
	})
	if err != nil {
		log.Printf("Couldn't populate table %v with users. Here's why: %v\n", tableName, err)
	}
	return err
}

// Scan scans the table for all items.
func (actor DynamoActions) Scan(ctx context.Context, tableName string) (UserList, error) {
	var userList UserList
	output, err := actor.DynamoClient.Scan(ctx, &dynamodb.ScanInput{
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't scan table %v for items. Here's why: %v\n", tableName, err)
	} else {
		err = attributevalue.UnmarshalListOfMaps(output.Items, &userList.Users)
		if err != nil {
			log.Printf("Couldn't unmarshal items into users. Here's why: %v\n", err)
		}
	}
	return userList, err
}

// AddUser adds a user item to a table.
func (actor DynamoActions) AddUser(ctx context.Context, tableName string, user User) error {
	userItem, err := attributevalue.MarshalMap(user)
	if err != nil {
		log.Printf("Couldn't marshall user to item. Here's why: %v\n", err)
	}
	_, err = actor.DynamoClient.PutItem(ctx, &dynamodb.PutItemInput{
		Item:      userItem,
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't put item in table %v. Here's why: %v", tableName, err)
	}
	return err
}
```
Create a struct that wraps CloudWatch Logs actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs/types"
)

type CloudWatchLogsActions struct {
	CwlClient *cloudwatchlogs.Client
}

// GetLatestLogStream gets the most recent log stream for a Lambda function.
func (actor CloudWatchLogsActions) GetLatestLogStream(ctx context.Context, functionName string) (types.LogStream, error) {
	var logStream types.LogStream
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.DescribeLogStreams(ctx, &cloudwatchlogs.DescribeLogStreamsInput{
		Descending:   aws.Bool(true),
		Limit:        aws.Int32(1),
		LogGroupName: aws.String(logGroupName),
		OrderBy:      types.OrderByLastEventTime,
	})
	if err != nil {
		log.Printf("Couldn't get log streams for log group %v. Here's why: %v\n", logGroupName, err)
	} else {
		logStream = output.LogStreams[0]
	}
	return logStream, err
}

// GetLogEvents gets the most recent eventCount events from the specified log stream.
func (actor CloudWatchLogsActions) GetLogEvents(ctx context.Context, functionName string, logStreamName string, eventCount int32) (
	[]types.OutputLogEvent, error) {
	var events []types.OutputLogEvent
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.GetLogEvents(ctx, &cloudwatchlogs.GetLogEventsInput{
		LogStreamName: aws.String(logStreamName),
		Limit:         aws.Int32(eventCount),
		LogGroupName:  aws.String(logGroupName),
	})
	if err != nil {
		log.Printf("Couldn't get log event for log stream %v. Here's why: %v\n", logStreamName, err)
	} else {
		events = output.Events
	}
	return events, err
}
```
Create a struct that wraps CloudFormation actions.  

```
import (
	"context"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
)

// StackOutputs defines a map of outputs from a specific stack.
type StackOutputs map[string]string

type CloudFormationActions struct {
	CfnClient *cloudformation.Client
}

// GetOutputs gets the outputs from a CloudFormation stack and puts them into a structured format.
func (actor CloudFormationActions) GetOutputs(ctx context.Context, stackName string) StackOutputs {
	output, err := actor.CfnClient.DescribeStacks(ctx, &cloudformation.DescribeStacksInput{
		StackName: aws.String(stackName),
	})
	if err != nil || len(output.Stacks) == 0 {
		log.Panicf("Couldn't find a CloudFormation stack named %v. Here's why: %v\n", stackName, err)
	}
	stackOutputs := StackOutputs{}
	for _, out := range output.Stacks[0].Outputs {
		stackOutputs[*out.OutputKey] = *out.OutputValue
	}
	return stackOutputs
}
```
Clean up resources.  

```
import (
	"context"
	"log"
	"user_pools_and_lambda_triggers/actions"

	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// Resources keeps track of AWS resources created during an example and handles
// cleanup when the example finishes.
type Resources struct {
	userPoolId       string
	userAccessTokens []string
	triggers         []actions.Trigger

	cognitoActor *actions.CognitoActions
	questioner   demotools.IQuestioner
}

func (resources *Resources) init(cognitoActor *actions.CognitoActions, questioner demotools.IQuestioner) {
	resources.userAccessTokens = []string{}
	resources.triggers = []actions.Trigger{}
	resources.cognitoActor = cognitoActor
	resources.questioner = questioner
}

// Cleanup deletes all AWS resources created during an example.
func (resources *Resources) Cleanup(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("Something went wrong during cleanup.\n%v\n", r)
			log.Println("Use the AWS Management Console to remove any remaining resources \n" +
				"that were created for this scenario.")
		}
	}()

	wantDelete := resources.questioner.AskBool("Do you want to remove all of the AWS resources that were created "+
		"during this demo (y/n)?", "y")
	if wantDelete {
		for _, accessToken := range resources.userAccessTokens {
			err := resources.cognitoActor.DeleteUser(ctx, accessToken)
			if err != nil {
				log.Println("Couldn't delete user during cleanup.")
				panic(err)
			}
			log.Println("Deleted user.")
		}
		triggerList := make([]actions.TriggerInfo, len(resources.triggers))
		for i := 0; i < len(resources.triggers); i++ {
			triggerList[i] = actions.TriggerInfo{Trigger: resources.triggers[i], HandlerArn: nil}
		}
		err := resources.cognitoActor.UpdateTriggers(ctx, resources.userPoolId, triggerList...)
		if err != nil {
			log.Println("Couldn't update Cognito triggers during cleanup.")
			panic(err)
		}
		log.Println("Removed Cognito triggers from user pool.")
	} else {
		log.Println("Be sure to remove resources when you're done with them to avoid unexpected charges!")
	}
}
```
+ For API details, see the following topics in *AWS SDK for Go API Reference*.
  + [ConfirmForgotPassword](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.ConfirmForgotPassword)
  + [DeleteUser](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.DeleteUser)
  + [ForgotPassword](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.ForgotPassword)
  + [InitiateAuth](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.InitiateAuth)
  + [SignUp](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.SignUp)
  + [UpdateUserPool](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.UpdateUserPool)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create an API Gateway REST API to track COVID-19 data
<a name="example_cross_ApiGatewayDataTracker_section"></a>

The following code example shows how to create a REST API that simulates a system to track daily cases of COVID-19 in the United States, using fictional data.

------
#### [ Python ]

**SDK for Python (Boto3)**  
 Shows how to use AWS Chalice with the AWS SDK for Python (Boto3) to create a serverless REST API that uses Amazon API Gateway, AWS Lambda, and Amazon DynamoDB. The REST API simulates a system that tracks daily cases of COVID-19 in the United States, using fictional data. Learn how to:   
+ Use AWS Chalice to define routes in Lambda functions that are called to handle REST requests that come through API Gateway.
+ Use Lambda functions to retrieve and store data in a DynamoDB table to serve REST requests.
+ Define table structure and security role resources in an AWS CloudFormation template.
+ Use AWS Chalice and CloudFormation to package and deploy all necessary resources.
+ Use CloudFormation to clean up all created resources.
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/apigateway_covid-19_tracker).   

**Services used in this example**
+ API Gateway
+ CloudFormation
+ DynamoDB
+ Lambda

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create a REST API with Lambda proxy integration
<a name="example_api_gateway_GettingStarted_087_section"></a>

The following code example shows how to:
+ Create an IAM role for Lambda execution
+ Create and deploy a Lambda function
+ Create a REST API
+ Configure Lambda proxy integration
+ Deploy and test the API
+ Clean up resources

------
#### [ Bash ]

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/087-apigateway-lambda-integration) repository. 

```
#!/bin/bash

# Simple API Gateway Lambda Integration Script
# This script creates a REST API with Lambda proxy integration

# Generate random identifiers
FUNCTION_NAME="GetStartedLambdaProxyIntegration-$(openssl rand -hex 4)"
ROLE_NAME="GetStartedLambdaBasicExecutionRole-$(openssl rand -hex 4)"
API_NAME="LambdaProxyAPI-$(openssl rand -hex 4)"

# Get AWS account info
ACCOUNT_ID=$(aws sts get-caller-identity --query Account --output text)
REGION=$(aws configure get region || echo "us-east-1")

echo "Creating Lambda function code..."

# Create Lambda function code
cat > lambda_function.py << 'EOF'
import json

def lambda_handler(event, context):
    print(event)
    
    greeter = 'World'
    
    try:
        if (event['queryStringParameters']) and (event['queryStringParameters']['greeter']) and (
                event['queryStringParameters']['greeter'] is not None):
            greeter = event['queryStringParameters']['greeter']
    except KeyError:
        print('No greeter')
    
    try:
        if (event['multiValueHeaders']) and (event['multiValueHeaders']['greeter']) and (
                event['multiValueHeaders']['greeter'] is not None):
            greeter = " and ".join(event['multiValueHeaders']['greeter'])
    except KeyError:
        print('No greeter')
    
    try:
        if (event['headers']) and (event['headers']['greeter']) and (
                event['headers']['greeter'] is not None):
            greeter = event['headers']['greeter']
    except KeyError:
        print('No greeter')
    
    if (event['body']) and (event['body'] is not None):
        body = json.loads(event['body'])
        try:
            if (body['greeter']) and (body['greeter'] is not None):
                greeter = body['greeter']
        except KeyError:
            print('No greeter')
    
    res = {
        "statusCode": 200,
        "headers": {
            "Content-Type": "*/*"
        },
        "body": "Hello, " + greeter + "!"
    }
    
    return res
EOF

# Create deployment package
zip function.zip lambda_function.py

echo "Creating IAM role..."

# Create IAM trust policy
cat > trust-policy.json << 'EOF'
{
  "Version":"2012-10-17",		 	 	 
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}
EOF

# Create IAM role
aws iam create-role \
    --role-name "$ROLE_NAME" \
    --assume-role-policy-document file://trust-policy.json

# Attach execution policy
aws iam attach-role-policy \
    --role-name "$ROLE_NAME" \
    --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"

# Wait for role propagation
sleep 15

echo "Creating Lambda function..."

# Create Lambda function
aws lambda create-function \
    --function-name "$FUNCTION_NAME" \
    --runtime python3.9 \
    --role "arn:aws:iam::$ACCOUNT_ID:role/$ROLE_NAME" \
    --handler lambda_function.lambda_handler \
    --zip-file fileb://function.zip

echo "Creating API Gateway..."

# Create REST API
aws apigateway create-rest-api \
    --name "$API_NAME" \
    --endpoint-configuration types=REGIONAL

# Get API ID
API_ID=$(aws apigateway get-rest-apis --query "items[?name=='$API_NAME'].id" --output text)

# Get root resource ID
ROOT_RESOURCE_ID=$(aws apigateway get-resources --rest-api-id "$API_ID" --query 'items[?path==`/`].id' --output text)

# Create helloworld resource
aws apigateway create-resource \
    --rest-api-id "$API_ID" \
    --parent-id "$ROOT_RESOURCE_ID" \
    --path-part helloworld

# Get resource ID
RESOURCE_ID=$(aws apigateway get-resources --rest-api-id "$API_ID" --query "items[?pathPart=='helloworld'].id" --output text)

# Create ANY method
aws apigateway put-method \
    --rest-api-id "$API_ID" \
    --resource-id "$RESOURCE_ID" \
    --http-method ANY \
    --authorization-type NONE

# Set up Lambda proxy integration
LAMBDA_URI="arn:aws:apigateway:$REGION:lambda:path/2015-03-31/functions/arn:aws:lambda:$REGION:$ACCOUNT_ID:function:$FUNCTION_NAME/invocations"

aws apigateway put-integration \
    --rest-api-id "$API_ID" \
    --resource-id "$RESOURCE_ID" \
    --http-method ANY \
    --type AWS_PROXY \
    --integration-http-method POST \
    --uri "$LAMBDA_URI"

# Grant API Gateway permission to invoke Lambda
SOURCE_ARN="arn:aws:execute-api:$REGION:$ACCOUNT_ID:$API_ID/*/*"

aws lambda add-permission \
    --function-name "$FUNCTION_NAME" \
    --statement-id "apigateway-invoke-$(openssl rand -hex 4)" \
    --action lambda:InvokeFunction \
    --principal apigateway.amazonaws.com \
    --source-arn "$SOURCE_ARN"

# Deploy API
aws apigateway create-deployment \
    --rest-api-id "$API_ID" \
    --stage-name test

echo "Testing API..."

# Test the API
INVOKE_URL="https://$API_ID.execute-api.$REGION.amazonaws.com/test/helloworld"

echo "API URL: $INVOKE_URL"

# Test with query parameter
echo "Testing with query parameter:"
curl -X GET "$INVOKE_URL?greeter=John"
echo ""

# Test with header
echo "Testing with header:"
curl -X GET "$INVOKE_URL" \
    -H 'content-type: application/json' \
    -H 'greeter: John'
echo ""

# Test with body
echo "Testing with POST body:"
curl -X POST "$INVOKE_URL" \
    -H 'content-type: application/json' \
    -d '{ "greeter": "John" }'
echo ""

echo "Tutorial completed! API is available at: $INVOKE_URL"

# Cleanup
echo "Cleaning up resources..."

# Delete API
aws apigateway delete-rest-api --rest-api-id "$API_ID"

# Delete Lambda function
aws lambda delete-function --function-name "$FUNCTION_NAME"

# Detach policy and delete role
aws iam detach-role-policy \
    --role-name "$ROLE_NAME" \
    --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"

aws iam delete-role --role-name "$ROLE_NAME"

# Clean up local files
rm -f lambda_function.py function.zip trust-policy.json

echo "Cleanup completed!"
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AddPermission](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/AddPermission)
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [CreateDeployment](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/CreateDeployment)
  + [CreateFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/CreateFunction)
  + [CreateResource](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/CreateResource)
  + [CreateRestApi](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/CreateRestApi)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/DeleteFunction)
  + [DeleteRestApi](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/DeleteRestApi)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetCallerIdentity](https://docs.aws.amazon.com/goto/aws-cli/sts-2011-06-15/GetCallerIdentity)
  + [GetResources](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/GetResources)
  + [GetRestApis](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/GetRestApis)
  + [PutIntegration](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/PutIntegration)
  + [PutMethod](https://docs.aws.amazon.com/goto/aws-cli/apigateway-2015-07-09/PutMethod)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create a lending library REST API
<a name="example_cross_AuroraRestLendingLibrary_section"></a>

The following code example shows how to create a lending library where patrons can borrow and return books by using a REST API backed by an Amazon Aurora database.

------
#### [ Python ]

**SDK for Python (Boto3)**  
 Shows how to use the AWS SDK for Python (Boto3) with the Amazon Relational Database Service (Amazon RDS) API and AWS Chalice to create a REST API backed by an Amazon Aurora database. The web service is fully serverless and represents a simple lending library where patrons can borrow and return books. Learn how to:   
+ Create and manage a serverless Aurora database cluster.
+ Use AWS Secrets Manager to manage database credentials.
+ Implement a data storage layer that uses Amazon RDS to move data into and out of the database.
+ Use AWS Chalice to deploy a serverless REST API to Amazon API Gateway and AWS Lambda.
+ Use the Requests package to send requests to the web service.
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/aurora_rest_lending_library).   

**Services used in this example**
+ API Gateway
+ Aurora
+ Lambda
+ Secrets Manager

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create a messenger application with Step Functions
<a name="example_cross_StepFunctionsMessenger_section"></a>

The following code example shows how to create an AWS Step Functions messenger application that retrieves message records from a database table.

------
#### [ Python ]

**SDK for Python (Boto3)**  
 Shows how to use the AWS SDK for Python (Boto3) with AWS Step Functions to create a messenger application that retrieves message records from an Amazon DynamoDB table and sends them with Amazon Simple Queue Service (Amazon SQS). The state machine integrates with an AWS Lambda function to scan the database for unsent messages.   
+ Create a state machine that retrieves and updates message records from an Amazon DynamoDB table.
+ Update the state machine definition to also send messages to Amazon Simple Queue Service (Amazon SQS).
+ Start and stop state machine runs.
+ Connect to Lambda, DynamoDB, and Amazon SQS from a state machine by using service integrations.
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/stepfunctions_messenger).   

**Services used in this example**
+ DynamoDB
+ Lambda
+ Amazon SQS
+ Step Functions

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create a photo asset management application that lets users manage photos using labels
<a name="example_cross_PAM_section"></a>

The following code examples show how to create a serverless application that lets users manage photos using labels.

------
#### [ .NET ]

**SDK for .NET**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/PhotoAssetManager).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/cross-service/photo_asset_manager).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/pam_source_files).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/photo-asset-manager).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ Kotlin ]

**SDK for Kotlin**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/usecases/creating_pam).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ PHP ]

**SDK for PHP**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/applications/photo_asset_manager).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------
#### [ Rust ]

**SDK for Rust**  
 Shows how to develop a photo asset management application that detects labels in images using Amazon Rekognition and stores them for later retrieval.   
For complete source code and instructions on how to set up and run, see the full example on [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/cross_service/photo_asset_management).  
For a deep dive into the origin of this example see the post on [AWS Community](https://community.aws/posts/cloud-journeys/01-serverless-image-recognition-app).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon Rekognition
+ Amazon S3
+ Amazon SNS

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create a websocket chat application with API Gateway
<a name="example_cross_ApiGatewayWebsocketChat_section"></a>

The following code example shows how to create a chat application that is served by a websocket API built on Amazon API Gateway.

------
#### [ Python ]

**SDK for Python (Boto3)**  
 Shows how to use the AWS SDK for Python (Boto3) with Amazon API Gateway V2 to create a websocket API that integrates with AWS Lambda and Amazon DynamoDB.   
+ Create a websocket API served by API Gateway.
+ Define a Lambda handler that stores connections in DynamoDB and posts messages to other chat participants.
+ Connect to the websocket chat application and send messages with the Websockets package.
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/cross_service/apigateway_websocket_chat).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Create an application that analyzes customer feedback and synthesizes audio
<a name="example_cross_FSA_section"></a>

The following code examples show how to create an application that analyzes customer comment cards, translates them from their original language, determines their sentiment, and generates an audio file from the translated text.

------
#### [ .NET ]

**SDK for .NET**  
 This example application analyzes and stores customer feedback cards. Specifically, it fulfills the need of a fictitious hotel in New York City. The hotel receives feedback from guests in various languages in the form of physical comment cards. That feedback is uploaded into the app through a web client. After an image of a comment card is uploaded, the following steps occur:   
+ Text is extracted from the image using Amazon Textract.
+ Amazon Comprehend determines the sentiment of the extracted text and its language.
+ The extracted text is translated to English using Amazon Translate.
+ Amazon Polly synthesizes an audio file from the extracted text.
 The full app can be deployed with the AWS CDK. For source code and deployment instructions, see the project in [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/FeedbackSentimentAnalyzer).   

**Services used in this example**
+ Amazon Comprehend
+ Lambda
+ Amazon Polly
+ Amazon Textract
+ Amazon Translate

------
#### [ Java ]

**SDK for Java 2.x**  
 This example application analyzes and stores customer feedback cards. Specifically, it fulfills the need of a fictitious hotel in New York City. The hotel receives feedback from guests in various languages in the form of physical comment cards. That feedback is uploaded into the app through a web client. After an image of a comment card is uploaded, the following steps occur:   
+ Text is extracted from the image using Amazon Textract.
+ Amazon Comprehend determines the sentiment of the extracted text and its language.
+ The extracted text is translated to English using Amazon Translate.
+ Amazon Polly synthesizes an audio file from the extracted text.
 The full app can be deployed with the AWS CDK. For source code and deployment instructions, see the project in [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_fsa_app).   

**Services used in this example**
+ Amazon Comprehend
+ Lambda
+ Amazon Polly
+ Amazon Textract
+ Amazon Translate

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 This example application analyzes and stores customer feedback cards. Specifically, it fulfills the need of a fictitious hotel in New York City. The hotel receives feedback from guests in various languages in the form of physical comment cards. That feedback is uploaded into the app through a web client. After an image of a comment card is uploaded, the following steps occur:   
+ Text is extracted from the image using Amazon Textract.
+ Amazon Comprehend determines the sentiment of the extracted text and its language.
+ The extracted text is translated to English using Amazon Translate.
+ Amazon Polly synthesizes an audio file from the extracted text.
 The full app can be deployed with the AWS CDK. For source code and deployment instructions, see the project in [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/feedback-sentiment-analyzer). The following excerpts show how the AWS SDK for JavaScript is used inside of Lambda functions.   

```
import {
  ComprehendClient,
  DetectDominantLanguageCommand,
  DetectSentimentCommand,
} from "@aws-sdk/client-comprehend";

/**
 * Determine the language and sentiment of the extracted text.
 *
 * @param {{ source_text: string}} extractTextOutput
 */
export const handler = async (extractTextOutput) => {
  const comprehendClient = new ComprehendClient({});

  const detectDominantLanguageCommand = new DetectDominantLanguageCommand({
    Text: extractTextOutput.source_text,
  });

  // The source language is required for sentiment analysis and
  // translation in the next step.
  const { Languages } = await comprehendClient.send(
    detectDominantLanguageCommand,
  );

  const languageCode = Languages[0].LanguageCode;

  const detectSentimentCommand = new DetectSentimentCommand({
    Text: extractTextOutput.source_text,
    LanguageCode: languageCode,
  });

  const { Sentiment } = await comprehendClient.send(detectSentimentCommand);

  return {
    sentiment: Sentiment,
    language_code: languageCode,
  };
};
```

```
import {
  DetectDocumentTextCommand,
  TextractClient,
} from "@aws-sdk/client-textract";

/**
 * Fetch the S3 object from the event and analyze it using Amazon Textract.
 *
 * @param {import("@types/aws-lambda").EventBridgeEvent<"Object Created">} eventBridgeS3Event
 */
export const handler = async (eventBridgeS3Event) => {
  const textractClient = new TextractClient();

  const detectDocumentTextCommand = new DetectDocumentTextCommand({
    Document: {
      S3Object: {
        Bucket: eventBridgeS3Event.bucket,
        Name: eventBridgeS3Event.object,
      },
    },
  });

  // Textract returns a list of blocks. A block can be a line, a page, word, etc.
  // Each block also contains geometry of the detected text.
  // For more information on the Block type, see https://docs.aws.amazon.com/textract/latest/dg/API_Block.html.
  const { Blocks } = await textractClient.send(detectDocumentTextCommand);

  // For the purpose of this example, we are only interested in words.
  const extractedWords = Blocks.filter((b) => b.BlockType === "WORD").map(
    (b) => b.Text,
  );

  return extractedWords.join(" ");
};
```

```
import { PollyClient, SynthesizeSpeechCommand } from "@aws-sdk/client-polly";
import { S3Client } from "@aws-sdk/client-s3";
import { Upload } from "@aws-sdk/lib-storage";

/**
 * Synthesize an audio file from text.
 *
 * @param {{ bucket: string, translated_text: string, object: string}} sourceDestinationConfig
 */
export const handler = async (sourceDestinationConfig) => {
  const pollyClient = new PollyClient({});

  const synthesizeSpeechCommand = new SynthesizeSpeechCommand({
    Engine: "neural",
    Text: sourceDestinationConfig.translated_text,
    VoiceId: "Ruth",
    OutputFormat: "mp3",
  });

  const { AudioStream } = await pollyClient.send(synthesizeSpeechCommand);

  const audioKey = `${sourceDestinationConfig.object}.mp3`;

  // Store the audio file in S3.
  const s3Client = new S3Client();
  const upload = new Upload({
    client: s3Client,
    params: {
      Bucket: sourceDestinationConfig.bucket,
      Key: audioKey,
      Body: AudioStream,
      ContentType: "audio/mp3",
    },
  });

  await upload.done();
  return audioKey;
};
```

```
import {
  TranslateClient,
  TranslateTextCommand,
} from "@aws-sdk/client-translate";

/**
 * Translate the extracted text to English.
 *
 * @param {{ extracted_text: string, source_language_code: string}} textAndSourceLanguage
 */
export const handler = async (textAndSourceLanguage) => {
  const translateClient = new TranslateClient({});

  const translateCommand = new TranslateTextCommand({
    SourceLanguageCode: textAndSourceLanguage.source_language_code,
    TargetLanguageCode: "en",
    Text: textAndSourceLanguage.extracted_text,
  });

  const { TranslatedText } = await translateClient.send(translateCommand);

  return { translated_text: TranslatedText };
};
```

**Services used in this example**
+ Amazon Comprehend
+ Lambda
+ Amazon Polly
+ Amazon Textract
+ Amazon Translate

------
#### [ Ruby ]

**SDK for Ruby**  
 This example application analyzes and stores customer feedback cards. Specifically, it fulfills the need of a fictitious hotel in New York City. The hotel receives feedback from guests in various languages in the form of physical comment cards. That feedback is uploaded into the app through a web client. After an image of a comment card is uploaded, the following steps occur:   
+ Text is extracted from the image using Amazon Textract.
+ Amazon Comprehend determines the sentiment of the extracted text and its language.
+ The extracted text is translated to English using Amazon Translate.
+ Amazon Polly synthesizes an audio file from the extracted text.
 The full app can be deployed with the AWS CDK. For source code and deployment instructions, see the project in [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/cross_service_examples/feedback_sentiment_analyzer).   

**Services used in this example**
+ Amazon Comprehend
+ Lambda
+ Amazon Polly
+ Amazon Textract
+ Amazon Translate

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Creating a CloudWatch dashboard with function name as a variable
<a name="example_cloudwatch_GettingStarted_031_section"></a>

The following code example shows how to:
+ Create a CloudWatch dashboard
+ Add Lambda metrics widgets with a function name variable
+ Verify the dashboard
+ Clean up resources

------
#### [ Bash ]

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/031-cloudwatch-dynamicdash) repository. 

```
#!/bin/bash

# Script to create a CloudWatch dashboard with Lambda function name as a variable
# This script creates a CloudWatch dashboard that allows you to switch between different Lambda functions

# Set up logging
LOG_FILE="cloudwatch-dashboard-script.log"
exec > >(tee -a "$LOG_FILE") 2>&1

echo "$(date): Starting CloudWatch dashboard creation script"

# Function to handle errors
handle_error() {
    echo "ERROR: $1"
    echo "Resources created:"
    echo "- CloudWatch Dashboard: LambdaMetricsDashboard"
    echo ""
    echo "==========================================="
    echo "CLEANUP CONFIRMATION"
    echo "==========================================="
    echo "An error occurred. Do you want to clean up the created resources? (y/n): "
    read -r CLEANUP_CHOICE
    
    if [[ "${CLEANUP_CHOICE,,}" == "y" ]]; then
        echo "Cleaning up resources..."
        aws cloudwatch delete-dashboards --dashboard-names LambdaMetricsDashboard
        echo "Cleanup complete."
    else
        echo "Resources were not cleaned up. You can manually delete them later."
    fi
    exit 1
}

# Check if AWS CLI is installed and configured
echo "Checking AWS CLI configuration..."
aws sts get-caller-identity > /dev/null 2>&1
if [ $? -ne 0 ]; then
    handle_error "AWS CLI is not properly configured. Please configure it with 'aws configure' and try again."
fi

# Get the current region
REGION=$(aws configure get region)
if [ -z "$REGION" ]; then
    REGION="us-east-1"
    echo "No region found in AWS config, defaulting to $REGION"
fi
echo "Using region: $REGION"

# Check if there are any Lambda functions in the account
echo "Checking for Lambda functions..."
LAMBDA_FUNCTIONS=$(aws lambda list-functions --query "Functions[*].FunctionName" --output text)
if [ -z "$LAMBDA_FUNCTIONS" ]; then
    echo "No Lambda functions found in your account. Creating a simple test function..."
    
    # Create a temporary directory for Lambda function code
    TEMP_DIR=$(mktemp -d)
    
    # Create a simple Lambda function
    cat > "$TEMP_DIR/index.js" << EOF
exports.handler = async (event) => {
    console.log('Event:', JSON.stringify(event, null, 2));
    return {
        statusCode: 200,
        body: JSON.stringify('Hello from Lambda!'),
    };
};
EOF
    
    # Zip the function code
    cd "$TEMP_DIR" || handle_error "Failed to change to temporary directory"
    zip -q function.zip index.js
    
    # Create a role for the Lambda function
    ROLE_NAME="LambdaDashboardTestRole"
    ROLE_ARN=$(aws iam create-role \
        --role-name "$ROLE_NAME" \
        --assume-role-policy-document '{"Version":"2012-10-17",		 	 	 "Statement":[{"Effect":"Allow","Principal":{"Service":"lambda.amazonaws.com"},"Action":"sts:AssumeRole"}]}' \
        --query "Role.Arn" \
        --output text)
    
    if [ $? -ne 0 ]; then
        handle_error "Failed to create IAM role for Lambda function"
    fi
    
    echo "Waiting for role to be available..."
    sleep 10
    
    # Attach basic Lambda execution policy
    aws iam attach-role-policy \
        --role-name "$ROLE_NAME" \
        --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
    
    if [ $? -ne 0 ]; then
        aws iam delete-role --role-name "$ROLE_NAME"
        handle_error "Failed to attach policy to IAM role"
    fi
    
    # Create the Lambda function
    FUNCTION_NAME="DashboardTestFunction"
    aws lambda create-function \
        --function-name "$FUNCTION_NAME" \
        --runtime nodejs18.x \
        --role "$ROLE_ARN" \
        --handler index.handler \
        --zip-file fileb://function.zip
    
    if [ $? -ne 0 ]; then
        aws iam detach-role-policy \
            --role-name "$ROLE_NAME" \
            --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        aws iam delete-role --role-name "$ROLE_NAME"
        handle_error "Failed to create Lambda function"
    fi
    
    # Invoke the function to generate some metrics
    echo "Invoking Lambda function to generate metrics..."
    for i in {1..5}; do
        aws lambda invoke --function-name "$FUNCTION_NAME" --payload '{}' /dev/null > /dev/null
        sleep 1
    done
    
    # Clean up temporary directory
    cd - > /dev/null
    rm -rf "$TEMP_DIR"
    
    # Set the function name for the dashboard
    DEFAULT_FUNCTION="$FUNCTION_NAME"
else
    # Use the first Lambda function as default
    DEFAULT_FUNCTION=$(echo "$LAMBDA_FUNCTIONS" | awk '{print $1}')
    echo "Found Lambda functions. Using $DEFAULT_FUNCTION as default."
fi

# Create a dashboard with Lambda metrics and a function name variable
echo "Creating CloudWatch dashboard with Lambda function name variable..."

# Create a JSON file for the dashboard body
cat > dashboard-body.json << EOF
{
  "widgets": [
    {
      "type": "metric",
      "x": 0,
      "y": 0,
      "width": 12,
      "height": 6,
      "properties": {
        "metrics": [
          [ "AWS/Lambda", "Invocations", "FunctionName", "\${FunctionName}" ],
          [ ".", "Errors", ".", "." ],
          [ ".", "Throttles", ".", "." ]
        ],
        "view": "timeSeries",
        "stacked": false,
        "region": "$REGION",
        "title": "Lambda Function Metrics for \${FunctionName}",
        "period": 300
      }
    },
    {
      "type": "metric",
      "x": 0,
      "y": 6,
      "width": 12,
      "height": 6,
      "properties": {
        "metrics": [
          [ "AWS/Lambda", "Duration", "FunctionName", "\${FunctionName}", { "stat": "Average" } ]
        ],
        "view": "timeSeries",
        "stacked": false,
        "region": "$REGION",
        "title": "Duration for \${FunctionName}",
        "period": 300
      }
    },
    {
      "type": "metric",
      "x": 12,
      "y": 0,
      "width": 12,
      "height": 6,
      "properties": {
        "metrics": [
          [ "AWS/Lambda", "ConcurrentExecutions", "FunctionName", "\${FunctionName}" ]
        ],
        "view": "timeSeries",
        "stacked": false,
        "region": "$REGION",
        "title": "Concurrent Executions for \${FunctionName}",
        "period": 300
      }
    }
  ],
  "periodOverride": "auto",
  "variables": [
    {
      "type": "property",
      "id": "FunctionName",
      "property": "FunctionName",
      "label": "Lambda Function",
      "inputType": "select",
      "values": [
        {
          "value": "$DEFAULT_FUNCTION",
          "label": "$DEFAULT_FUNCTION"
        }
      ]
    }
  ]
}
EOF

# Create the dashboard using the JSON file
DASHBOARD_RESULT=$(aws cloudwatch put-dashboard --dashboard-name LambdaMetricsDashboard --dashboard-body file://dashboard-body.json)
DASHBOARD_EXIT_CODE=$?

# Check if there was a fatal error
if [ $DASHBOARD_EXIT_CODE -ne 0 ]; then
    # If we created resources, clean them up
    if [ -n "${FUNCTION_NAME:-}" ]; then
        aws lambda delete-function --function-name "$FUNCTION_NAME"
        aws iam detach-role-policy \
            --role-name "$ROLE_NAME" \
            --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        aws iam delete-role --role-name "$ROLE_NAME"
    fi
    handle_error "Failed to create CloudWatch dashboard."
fi

# Display any validation messages but continue
if [[ "$DASHBOARD_RESULT" == *"DashboardValidationMessages"* ]]; then
    echo "Dashboard created with validation messages:"
    echo "$DASHBOARD_RESULT"
    echo "These validation messages are warnings and the dashboard should still function."
else
    echo "Dashboard created successfully!"
fi

# Verify the dashboard was created
echo "Verifying dashboard creation..."
DASHBOARD_INFO=$(aws cloudwatch get-dashboard --dashboard-name LambdaMetricsDashboard)
DASHBOARD_INFO_EXIT_CODE=$?

if [ $DASHBOARD_INFO_EXIT_CODE -ne 0 ]; then
    # If we created resources, clean them up
    if [ -n "${FUNCTION_NAME:-}" ]; then
        aws lambda delete-function --function-name "$FUNCTION_NAME"
        aws iam detach-role-policy \
            --role-name "$ROLE_NAME" \
            --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        aws iam delete-role --role-name "$ROLE_NAME"
    fi
    handle_error "Failed to verify dashboard creation."
fi

echo "Dashboard verification successful!"
echo "Dashboard details:"
echo "$DASHBOARD_INFO"

# List all dashboards to confirm
echo "Listing all dashboards:"
DASHBOARDS=$(aws cloudwatch list-dashboards)
DASHBOARDS_EXIT_CODE=$?

if [ $DASHBOARDS_EXIT_CODE -ne 0 ]; then
    # If we created resources, clean them up
    if [ -n "${FUNCTION_NAME:-}" ]; then
        aws lambda delete-function --function-name "$FUNCTION_NAME"
        aws iam detach-role-policy \
            --role-name "$ROLE_NAME" \
            --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        aws iam delete-role --role-name "$ROLE_NAME"
    fi
    handle_error "Failed to list dashboards."
fi
echo "$DASHBOARDS"

# Show instructions for accessing the dashboard
echo ""
echo "Dashboard created successfully! To access it:"
echo "1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/"
echo "2. In the navigation pane, choose Dashboards"
echo "3. Select LambdaMetricsDashboard"
echo "4. You should see a dropdown menu labeled 'Lambda Function' at the top of the dashboard"
echo "5. Use this dropdown to select different Lambda functions and see their metrics"
echo ""

# Create a list of resources for cleanup
RESOURCES=("- CloudWatch Dashboard: LambdaMetricsDashboard")
if [ -n "${FUNCTION_NAME:-}" ]; then
    RESOURCES+=("- Lambda Function: $FUNCTION_NAME")
    RESOURCES+=("- IAM Role: $ROLE_NAME")
fi

# Prompt for cleanup
echo "==========================================="
echo "CLEANUP CONFIRMATION"
echo "==========================================="
echo "Resources created:"
for resource in "${RESOURCES[@]}"; do
    echo "$resource"
done
echo ""
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "${CLEANUP_CHOICE,,}" == "y" ]]; then
    echo "Cleaning up resources..."
    
    # Delete the dashboard
    aws cloudwatch delete-dashboards --dashboard-names LambdaMetricsDashboard
    if [ $? -ne 0 ]; then
        echo "WARNING: Failed to delete dashboard. You may need to delete it manually."
    else
        echo "Dashboard deleted successfully."
    fi
    
    # If we created a Lambda function, delete it and its role
    if [ -n "${FUNCTION_NAME:-}" ]; then
        echo "Deleting Lambda function..."
        aws lambda delete-function --function-name "$FUNCTION_NAME"
        if [ $? -ne 0 ]; then
            echo "WARNING: Failed to delete Lambda function. You may need to delete it manually."
        else
            echo "Lambda function deleted successfully."
        fi
        
        echo "Detaching role policy..."
        aws iam detach-role-policy \
            --role-name "$ROLE_NAME" \
            --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        if [ $? -ne 0 ]; then
            echo "WARNING: Failed to detach role policy. You may need to detach it manually."
        else
            echo "Role policy detached successfully."
        fi
        
        echo "Deleting IAM role..."
        aws iam delete-role --role-name "$ROLE_NAME"
        if [ $? -ne 0 ]; then
            echo "WARNING: Failed to delete IAM role. You may need to delete it manually."
        else
            echo "IAM role deleted successfully."
        fi
    fi
    
    # Clean up the JSON file
    rm -f dashboard-body.json
    
    echo "Cleanup complete."
else
    echo "Resources were not cleaned up. You can manually delete them later with:"
    echo "aws cloudwatch delete-dashboards --dashboard-names LambdaMetricsDashboard"
    if [ -n "${FUNCTION_NAME:-}" ]; then
        echo "aws lambda delete-function --function-name $FUNCTION_NAME"
        echo "aws iam detach-role-policy --role-name $ROLE_NAME --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        echo "aws iam delete-role --role-name $ROLE_NAME"
    fi
fi

echo "Script completed successfully!"
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [CreateFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/CreateFunction)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [DeleteDashboards](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/DeleteDashboards)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/DeleteFunction)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetCallerIdentity](https://docs.aws.amazon.com/goto/aws-cli/sts-2011-06-15/GetCallerIdentity)
  + [GetDashboard](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/GetDashboard)
  + [Invoke](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/Invoke)
  + [ListDashboards](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/ListDashboards)
  + [ListFunctions](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/ListFunctions)
  + [PutDashboard](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/PutDashboard)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Creating your first Lambda function
<a name="example_lambda_GettingStarted_019_section"></a>

The following code example shows how to:
+ Create an IAM role for Lambda
+ Create function code
+ Create a Lambda function
+ Test your Lambda function
+ Clean up resources

------
#### [ Bash ]

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/019-lambda-gettingstarted) repository. 

```
#!/bin/bash
# AWS Lambda - Create Your First Function
# This script creates a Lambda function, invokes it with a test event,
# views CloudWatch logs, and cleans up all resources.
#
# Source: https://docs.aws.amazon.com/lambda/latest/dg/getting-started.html
#
# Resources created:
#   - IAM role (Lambda execution role with basic logging permissions)
#   - Lambda function (Python 3.13 or Node.js 22.x runtime)
#   - CloudWatch log group (created automatically by Lambda on invocation)

set -eE

###############################################################################
# Setup
###############################################################################

UNIQUE_ID=$(cat /dev/urandom | tr -dc 'a-z0-9' | fold -w 8 | head -n 1)
FUNCTION_NAME="my-lambda-function-${UNIQUE_ID}"
ROLE_NAME="lambda-execution-role-${UNIQUE_ID}"
LOG_GROUP_NAME="/aws/lambda/${FUNCTION_NAME}"

TEMP_DIR=$(mktemp -d)
LOG_FILE="${TEMP_DIR}/lambda-gettingstarted.log"

exec > >(tee -a "$LOG_FILE") 2>&1

declare -a CREATED_RESOURCES

###############################################################################
# Helper functions
###############################################################################

cleanup_resources() {
    # Disable error trap to prevent recursion during cleanup
    trap - ERR
    set +eE

    echo ""
    echo "Cleaning up resources..."
    echo ""

    for ((i=${#CREATED_RESOURCES[@]}-1; i>=0; i--)); do
        local RESOURCE="${CREATED_RESOURCES[$i]}"
        local TYPE="${RESOURCE%%:*}"
        local NAME="${RESOURCE#*:}"

        case "$TYPE" in
            log-group)
                echo "Deleting CloudWatch log group: ${NAME}"
                aws logs delete-log-group \
                    --log-group-name "$NAME" 2>&1 || echo "  WARNING: Could not delete log group ${NAME}."
                ;;
            lambda-function)
                echo "Deleting Lambda function: ${NAME}"
                aws lambda delete-function \
                    --function-name "$NAME" 2>&1 || echo "  WARNING: Could not delete Lambda function ${NAME}."
                echo "  Waiting for function deletion to complete..."
                local DELETE_WAIT=0
                while aws lambda get-function --function-name "$NAME" > /dev/null 2>&1; do
                    sleep 2
                    DELETE_WAIT=$((DELETE_WAIT + 2))
                    if [ "$DELETE_WAIT" -ge 60 ]; then
                        echo "  WARNING: Timed out waiting for function deletion."
                        break
                    fi
                done
                ;;
            iam-role-policy)
                local ROLE_PART="${NAME%%|*}"
                local POLICY_PART="${NAME#*|}"
                echo "Detaching policy from role: ${ROLE_PART}"
                aws iam detach-role-policy \
                    --role-name "$ROLE_PART" \
                    --policy-arn "$POLICY_PART" 2>&1 || echo "  WARNING: Could not detach policy from role ${ROLE_PART}."
                ;;
            iam-role)
                echo "Deleting IAM role: ${NAME}"
                aws iam delete-role \
                    --role-name "$NAME" 2>&1 || echo "  WARNING: Could not delete IAM role ${NAME}."
                ;;
        esac
    done

    if [ -d "$TEMP_DIR" ]; then
        rm -rf "$TEMP_DIR"
    fi

    echo ""
    echo "Cleanup complete."
}

handle_error() {
    echo ""
    echo "==========================================="
    echo "ERROR: Script failed at $1"
    echo "==========================================="
    echo ""
    if [ ${#CREATED_RESOURCES[@]} -gt 0 ]; then
        echo "Attempting to clean up ${#CREATED_RESOURCES[@]} resource(s)..."
        cleanup_resources
    fi
    exit 1
}

trap 'handle_error "line $LINENO"' ERR

wait_for_resource() {
    local DESCRIPTION="$1"
    local COMMAND="$2"
    local TARGET_VALUE="$3"
    local TIMEOUT=300
    local ELAPSED=0
    local INTERVAL=5

    echo "Waiting for ${DESCRIPTION}..."
    while true; do
        local RESULT
        RESULT=$(eval "$COMMAND" 2>&1) || true
        if echo "$RESULT" | grep -q "$TARGET_VALUE"; then
            echo "  ${DESCRIPTION} is ready."
            return 0
        fi
        if [ "$ELAPSED" -ge "$TIMEOUT" ]; then
            echo "ERROR: Timed out waiting for ${DESCRIPTION} after ${TIMEOUT} seconds."
            return 1
        fi
        sleep "$INTERVAL"
        ELAPSED=$((ELAPSED + INTERVAL))
    done
}

###############################################################################
# Region pre-check
###############################################################################

CONFIGURED_REGION=$(aws configure get region 2>/dev/null || true)
if [ -z "$CONFIGURED_REGION" ] && [ -z "$AWS_DEFAULT_REGION" ] && [ -z "$AWS_REGION" ]; then
    echo "ERROR: No AWS region configured."
    echo "Run 'aws configure set region <region>' or export AWS_DEFAULT_REGION."
    exit 1
fi

###############################################################################
# Runtime selection
###############################################################################

echo ""
echo "==========================================="
echo "AWS Lambda - Create Your First Function"
echo "==========================================="
echo ""
echo "Select a runtime for your Lambda function:"
echo "  1) Python 3.13"
echo "  2) Node.js 22.x"
echo ""
echo "Enter your choice (1 or 2): "
read -r RUNTIME_CHOICE

case "$RUNTIME_CHOICE" in
    1)
        RUNTIME="python3.13"
        HANDLER="lambda_function.lambda_handler"
        CODE_FILE="lambda_function.py"
        cat > "${TEMP_DIR}/${CODE_FILE}" << 'PYTHON_EOF'
import json
import logging
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def lambda_handler(event, context):
    length = event['length']
    width = event['width']
    area = calculate_area(length, width)
    print(f'The area is {area}')
    logger.info(f'CloudWatch logs group: {context.log_group_name}')
    return json.dumps({'area': area})
def calculate_area(length, width):
    return length * width
PYTHON_EOF
        echo "Selected runtime: Python 3.13"
        ;;
    2)
        RUNTIME="nodejs22.x"
        HANDLER="index.handler"
        CODE_FILE="index.mjs"
        cat > "${TEMP_DIR}/${CODE_FILE}" << 'NODEJS_EOF'
export const handler = async (event, context) => {
  const area = event.length * event.width;
  console.log(`The area is ${area}`);
  console.log('CloudWatch log group: ', context.logGroupName);
  return JSON.stringify({area});
};
NODEJS_EOF
        echo "Selected runtime: Node.js 22.x"
        ;;
    *)
        echo "ERROR: Invalid choice. Please enter 1 or 2."
        exit 1
        ;;
esac

###############################################################################
# Step 1: Create IAM execution role
###############################################################################

echo ""
echo "==========================================="
echo "Step 1: Create IAM execution role"
echo "==========================================="
echo ""

TRUST_POLICY='{
    "Version":"2012-10-17",		 	 	 
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "lambda.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
        }
    ]
}'

echo "Creating IAM role: ${ROLE_NAME}"
ROLE_OUTPUT=$(aws iam create-role \
    --role-name "$ROLE_NAME" \
    --assume-role-policy-document "$TRUST_POLICY" \
    --query 'Role.Arn' \
    --output text 2>&1)
echo "$ROLE_OUTPUT"
ROLE_ARN="$ROLE_OUTPUT"
CREATED_RESOURCES+=("iam-role:${ROLE_NAME}")
echo "Role ARN: ${ROLE_ARN}"

echo ""
echo "Attaching AWSLambdaBasicExecutionRole policy..."
aws iam attach-role-policy \
    --role-name "$ROLE_NAME" \
    --policy-arn "arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole" 2>&1
CREATED_RESOURCES+=("iam-role-policy:${ROLE_NAME}|arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole")
echo "Policy attached."

# IAM roles can take a few seconds to propagate
echo "Waiting for IAM role to propagate..."
sleep 10

###############################################################################
# Step 2: Create Lambda function
###############################################################################

echo ""
echo "==========================================="
echo "Step 2: Create Lambda function"
echo "==========================================="
echo ""

echo "Creating deployment package..."
ORIGINAL_DIR=$(pwd)
cd "$TEMP_DIR"
zip -j function.zip "$CODE_FILE" > /dev/null 2>&1
cd "$ORIGINAL_DIR"

echo "Creating Lambda function: ${FUNCTION_NAME}"
echo "  Runtime: ${RUNTIME}"
echo "  Handler: ${HANDLER}"
echo ""

CREATE_OUTPUT=$(aws lambda create-function \
    --function-name "$FUNCTION_NAME" \
    --runtime "$RUNTIME" \
    --role "$ROLE_ARN" \
    --handler "$HANDLER" \
    --architectures x86_64 \
    --zip-file "fileb://${TEMP_DIR}/function.zip" \
    --query '[FunctionName, FunctionArn, Runtime, State]' \
    --output text 2>&1)
echo "$CREATE_OUTPUT"
CREATED_RESOURCES+=("lambda-function:${FUNCTION_NAME}")

wait_for_resource "Lambda function to become Active" \
    "aws lambda get-function-configuration --function-name ${FUNCTION_NAME} --query State --output text" \
    "Active"

###############################################################################
# Step 3: Invoke the function
###############################################################################

echo ""
echo "==========================================="
echo "Step 3: Invoke the function"
echo "==========================================="
echo ""

TEST_EVENT='{"length": 6, "width": 7}'
echo "Invoking function with test event: ${TEST_EVENT}"
echo ""

echo "$TEST_EVENT" > "${TEMP_DIR}/test-event.json"

INVOKE_OUTPUT=$(aws lambda invoke \
    --function-name "$FUNCTION_NAME" \
    --payload "fileb://${TEMP_DIR}/test-event.json" \
    --cli-read-timeout 30 \
    "${TEMP_DIR}/response.json" 2>&1)
echo "$INVOKE_OUTPUT"

RESPONSE=$(cat "${TEMP_DIR}/response.json")
echo ""
echo "Function response: ${RESPONSE}"
echo ""

if echo "$INVOKE_OUTPUT" | grep -qi "functionerror"; then
    echo "WARNING: Function returned an error."
fi

###############################################################################
# Step 4: View CloudWatch logs
###############################################################################

echo ""
echo "==========================================="
echo "Step 4: View CloudWatch Logs"
echo "==========================================="
echo ""

echo "Log group: ${LOG_GROUP_NAME}"
echo ""

echo "Waiting for CloudWatch logs to be available..."

LOG_STREAMS=""
for i in $(seq 1 6); do
    LOG_STREAMS=$(aws logs describe-log-streams \
        --log-group-name "$LOG_GROUP_NAME" \
        --order-by LastEventTime \
        --descending \
        --query 'logStreams[0].logStreamName' \
        --output text 2>/dev/null) || true
    if [ -n "$LOG_STREAMS" ] && [ "$LOG_STREAMS" != "None" ]; then
        break
    fi
    LOG_STREAMS=""
    sleep 5
done

if [ -n "$LOG_STREAMS" ] && [ "$LOG_STREAMS" != "None" ]; then
    echo "Latest log stream: ${LOG_STREAMS}"
    echo ""
    echo "--- Log events ---"
    LOG_EVENTS=$(aws logs get-log-events \
        --log-group-name "$LOG_GROUP_NAME" \
        --log-stream-name "$LOG_STREAMS" \
        --query 'events[].message' \
        --output text 2>&1) || true
    echo "$LOG_EVENTS"
    echo "--- End of log events ---"
else
    echo "No log streams found yet. Logs may take a moment to appear."
    echo "You can view them in the CloudWatch console:"
    echo "  Log group: ${LOG_GROUP_NAME}"
fi

CREATED_RESOURCES+=("log-group:${LOG_GROUP_NAME}")

###############################################################################
# Summary and cleanup
###############################################################################

echo ""
echo "==========================================="
echo "SUMMARY"
echo "==========================================="
echo ""
echo "Resources created:"
echo "  IAM role:          ${ROLE_NAME}"
echo "  Lambda function:   ${FUNCTION_NAME}"
echo "  CloudWatch logs:   ${LOG_GROUP_NAME}"
echo ""
echo "==========================================="
echo "CLEANUP CONFIRMATION"
echo "==========================================="
echo ""
echo "Do you want to clean up all created resources? (y/n): "
read -r CLEANUP_CHOICE

if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
    cleanup_resources
else
    echo ""
    echo "Resources were NOT deleted. To clean up manually, run:"
    echo ""
    echo "  # Delete the Lambda function"
    echo "  aws lambda delete-function --function-name ${FUNCTION_NAME}"
    echo ""
    echo "  # Delete the CloudWatch log group"
    echo "  aws logs delete-log-group --log-group-name ${LOG_GROUP_NAME}"
    echo ""
    echo "  # Detach the policy and delete the IAM role"
    echo "  aws iam detach-role-policy --role-name ${ROLE_NAME} --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
    echo "  aws iam delete-role --role-name ${ROLE_NAME}"
    echo ""

    if [ -d "$TEMP_DIR" ]; then
        rm -rf "$TEMP_DIR"
    fi
fi

echo ""
echo "Done."
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [CreateFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/CreateFunction)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/DeleteFunction)
  + [DeleteLogGroup](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/DeleteLogGroup)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DescribeLogStreams](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/DescribeLogStreams)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/GetFunction)
  + [GetFunctionConfiguration](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/GetFunctionConfiguration)
  + [GetLogEvents](https://docs.aws.amazon.com/goto/aws-cli/logs-2014-03-28/GetLogEvents)
  + [Invoke](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/Invoke)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from a browser
<a name="example_cross_LambdaForBrowser_section"></a>

The following code example shows how to invoke an AWS Lambda function from a browser.

------
#### [ JavaScript ]

**SDK for JavaScript (v2)**  
 You can create a browser-based application that uses an AWS Lambda function to update an Amazon DynamoDB table with user selections.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/lambda/lambda-for-browser).   

**Services used in this example**
+ DynamoDB
+ Lambda

**SDK for JavaScript (v3)**  
 You can create a browser-based application that uses an AWS Lambda function to update an Amazon DynamoDB table with user selections. This app uses AWS SDK for JavaScript v3.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/lambda-for-browser).   

**Services used in this example**
+ DynamoDB
+ Lambda

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Transform data for your application with S3 Object Lambda
<a name="example_cross_ServerlessS3DataTransformation_section"></a>

The following code example shows how to transform data for your application with S3 Object Lambda.

------
#### [ .NET ]

**SDK for .NET**  
 Shows how to add custom code to standard S3 GET requests to modify the requested object retrieved from S3 so that the object suit the needs of the requesting client or application.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv3/cross-service/S3ObjectLambdaFunction).   

**Services used in this example**
+ Lambda
+ Amazon S3

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use API Gateway to invoke a Lambda function
<a name="example_cross_LambdaAPIGateway_section"></a>

The following code examples show how to create an AWS Lambda function invoked by Amazon API Gateway.

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to create an AWS Lambda function by using the Lambda Java runtime API. This example invokes different AWS services to perform a specific use case. This example demonstrates how to create a Lambda function invoked by Amazon API Gateway that scans an Amazon DynamoDB table for work anniversaries and uses Amazon Simple Notification Service (Amazon SNS) to send a text message to your employees that congratulates them at their one year anniversary date.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_lambda_apigateway).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon SNS

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 Shows how to create an AWS Lambda function by using the Lambda JavaScript runtime API. This example invokes different AWS services to perform a specific use case. This example demonstrates how to create a Lambda function invoked by Amazon API Gateway that scans an Amazon DynamoDB table for work anniversaries and uses Amazon Simple Notification Service (Amazon SNS) to send a text message to your employees that congratulates them at their one year anniversary date.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/lambda-api-gateway).   
This example is also available in the [AWS SDK for JavaScript v3 developer guide](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/api-gateway-invoking-lambda-example.html).  

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon SNS

------
#### [ Python ]

**SDK for Python (Boto3)**  
 This example shows how to create and use an Amazon API Gateway REST API that targets an AWS Lambda function. The Lambda handler demonstrates how to route based on HTTP methods; how to get data from the query string, header, and body; and how to return a JSON response.   
+ Deploy a Lambda function.
+ Create an API Gateway REST API.
+ Create a REST resource that targets the Lambda function.
+ Grant permission to let API Gateway invoke the Lambda function.
+ Use the Requests package to send requests to the REST API.
+ Clean up all resources created during the demo.
 This example is best viewed on GitHub. For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#readme).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda
+ Amazon SNS

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use Step Functions to invoke Lambda functions
<a name="example_cross_ServerlessWorkflows_section"></a>

The following code example shows how to create an AWS Step Functions state machine that invokes AWS Lambda functions in sequence.

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to create an AWS serverless workflow by using AWS Step Functions and the AWS SDK for Java 2.x. Each workflow step is implemented using an AWS Lambda function.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_workflows_stepfunctions).   

**Services used in this example**
+ DynamoDB
+ Lambda
+ Amazon SES
+ Step Functions

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use scheduled events to invoke a Lambda function
<a name="example_cross_LambdaScheduledEvents_section"></a>

The following code examples show how to create an AWS Lambda function invoked by an Amazon EventBridge scheduled event.

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to create an Amazon EventBridge scheduled event that invokes an AWS Lambda function. Configure EventBridge to use a cron expression to schedule when the Lambda function is invoked. In this example, you create a Lambda function by using the Lambda Java runtime API. This example invokes different AWS services to perform a specific use case. This example demonstrates how to create an app that sends a mobile text message to your employees that congratulates them at the one year anniversary date.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_scheduled_events).   

**Services used in this example**
+ CloudWatch Logs
+ DynamoDB
+ EventBridge
+ Lambda
+ Amazon SNS

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 Shows how to create an Amazon EventBridge scheduled event that invokes an AWS Lambda function. Configure EventBridge to use a cron expression to schedule when the Lambda function is invoked. In this example, you create a Lambda function by using the Lambda JavaScript runtime API. This example invokes different AWS services to perform a specific use case. This example demonstrates how to create an app that sends a mobile text message to your employees that congratulates them at the one year anniversary date.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cross-services/lambda-scheduled-events).   
This example is also available in the [AWS SDK for JavaScript v3 developer guide](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/scheduled-events-invoking-lambda-example.html).  

**Services used in this example**
+ CloudWatch Logs
+ DynamoDB
+ EventBridge
+ Lambda
+ Amazon SNS

------
#### [ Python ]

**SDK for Python (Boto3)**  
 This example shows how to register an AWS Lambda function as the target of a scheduled Amazon EventBridge event. The Lambda handler writes a friendly message and the full event data to Amazon CloudWatch Logs for later retrieval.   
+ Deploys a Lambda function.
+ Creates an EventBridge scheduled event and makes the Lambda function the target.
+ Grants permission to let EventBridge invoke the Lambda function.
+ Prints the latest data from CloudWatch Logs to show the result of the scheduled invocations.
+ Cleans up all resources created during the demo.
 This example is best viewed on GitHub. For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/lambda#readme).   

**Services used in this example**
+ CloudWatch Logs
+ DynamoDB
+ EventBridge
+ Lambda
+ Amazon SNS

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Use the Amazon Neptune API to develop a Lambda function that queries graph data
<a name="example_cross_Neptune_Query_section"></a>

The following code example shows how to use the Neptune API to query graph data.

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to use Amazon Neptune Java API to create a Lambda function that queries graph data within the VPC.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_neptune_lambda).   

**Services used in this example**
+ Lambda
+ Neptune

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Using property variables in CloudWatch dashboards to monitor multiple Lambda functions
<a name="example_iam_GettingStarted_032_section"></a>

The following code example shows how to:
+ Create Lambda functions for monitoring
+ Create a CloudWatch dashboard
+ Add a property variable to the dashboard
+ Clean up resources

------
#### [ Bash ]

**AWS CLI with Bash script**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Sample developer tutorials](https://github.com/aws-samples/sample-developer-tutorials/tree/main/tuts/032-cloudwatch-streams) repository. 

```
#!/bin/bash

# CloudWatch Dashboard with Lambda Function Variable Script
# This script creates a CloudWatch dashboard with a property variable for Lambda function names

# Set up logging
LOG_FILE="cloudwatch-dashboard-script-v4.log"
echo "Starting script execution at $(date)" > "$LOG_FILE"

# Function to log commands and their output
log_cmd() {
    echo "$(date): Running command: $1" >> "$LOG_FILE"
    eval "$1" 2>&1 | tee -a "$LOG_FILE"
    return ${PIPESTATUS[0]}
}

# Function to check for errors in command output
check_error() {
    local cmd_output="$1"
    local cmd_status="$2"
    local error_msg="$3"
    
    if [ $cmd_status -ne 0 ] || echo "$cmd_output" | grep -i "error" > /dev/null; then
        echo "ERROR: $error_msg" | tee -a "$LOG_FILE"
        echo "Command output: $cmd_output" | tee -a "$LOG_FILE"
        cleanup_resources
        exit 1
    fi
}

# Function to clean up resources
cleanup_resources() {
    echo "" | tee -a "$LOG_FILE"
    echo "==========================================" | tee -a "$LOG_FILE"
    echo "CLEANUP PROCESS" | tee -a "$LOG_FILE"
    echo "==========================================" | tee -a "$LOG_FILE"
    
    if [ -n "$DASHBOARD_NAME" ]; then
        echo "Deleting CloudWatch dashboard: $DASHBOARD_NAME" | tee -a "$LOG_FILE"
        log_cmd "aws cloudwatch delete-dashboards --dashboard-names \"$DASHBOARD_NAME\""
    fi
    
    if [ -n "$LAMBDA_FUNCTION1" ]; then
        echo "Deleting Lambda function: $LAMBDA_FUNCTION1" | tee -a "$LOG_FILE"
        log_cmd "aws lambda delete-function --function-name \"$LAMBDA_FUNCTION1\""
    fi
    
    if [ -n "$LAMBDA_FUNCTION2" ]; then
        echo "Deleting Lambda function: $LAMBDA_FUNCTION2" | tee -a "$LOG_FILE"
        log_cmd "aws lambda delete-function --function-name \"$LAMBDA_FUNCTION2\""
    fi
    
    if [ -n "$ROLE_NAME" ]; then
        echo "Detaching policy from role: $ROLE_NAME" | tee -a "$LOG_FILE"
        log_cmd "aws iam detach-role-policy --role-name \"$ROLE_NAME\" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole"
        
        echo "Deleting IAM role: $ROLE_NAME" | tee -a "$LOG_FILE"
        log_cmd "aws iam delete-role --role-name \"$ROLE_NAME\""
    fi
    
    echo "Cleanup completed." | tee -a "$LOG_FILE"
}

# Function to prompt for cleanup confirmation
confirm_cleanup() {
    echo "" | tee -a "$LOG_FILE"
    echo "==========================================" | tee -a "$LOG_FILE"
    echo "CLEANUP CONFIRMATION" | tee -a "$LOG_FILE"
    echo "==========================================" | tee -a "$LOG_FILE"
    echo "The following resources were created:" | tee -a "$LOG_FILE"
    echo "- CloudWatch Dashboard: $DASHBOARD_NAME" | tee -a "$LOG_FILE"
    
    if [ -n "$LAMBDA_FUNCTION1" ]; then
        echo "- Lambda Function: $LAMBDA_FUNCTION1" | tee -a "$LOG_FILE"
    fi
    
    if [ -n "$LAMBDA_FUNCTION2" ]; then
        echo "- Lambda Function: $LAMBDA_FUNCTION2" | tee -a "$LOG_FILE"
    fi
    
    if [ -n "$ROLE_NAME" ]; then
        echo "- IAM Role: $ROLE_NAME" | tee -a "$LOG_FILE"
    fi
    
    echo "" | tee -a "$LOG_FILE"
    echo "Do you want to clean up all created resources? (y/n): " | tee -a "$LOG_FILE"
    read -r CLEANUP_CHOICE
    
    if [[ "$CLEANUP_CHOICE" =~ ^[Yy]$ ]]; then
        cleanup_resources
    else
        echo "Resources were not cleaned up. You can manually delete them later." | tee -a "$LOG_FILE"
    fi
}

# Get AWS region
AWS_REGION=$(aws configure get region)
if [ -z "$AWS_REGION" ]; then
    AWS_REGION="us-east-1"
    echo "No region found in AWS config, defaulting to $AWS_REGION" | tee -a "$LOG_FILE"
else
    echo "Using AWS region: $AWS_REGION" | tee -a "$LOG_FILE"
fi

# Generate unique identifiers
RANDOM_ID=$(openssl rand -hex 6)
DASHBOARD_NAME="LambdaMetricsDashboard-${RANDOM_ID}"
LAMBDA_FUNCTION1="TestFunction1-${RANDOM_ID}"
LAMBDA_FUNCTION2="TestFunction2-${RANDOM_ID}"
ROLE_NAME="LambdaExecutionRole-${RANDOM_ID}"

echo "Using random identifier: $RANDOM_ID" | tee -a "$LOG_FILE"
echo "Dashboard name: $DASHBOARD_NAME" | tee -a "$LOG_FILE"
echo "Lambda function names: $LAMBDA_FUNCTION1, $LAMBDA_FUNCTION2" | tee -a "$LOG_FILE"
echo "IAM role name: $ROLE_NAME" | tee -a "$LOG_FILE"

# Create IAM role for Lambda functions
echo "Creating IAM role for Lambda..." | tee -a "$LOG_FILE"
TRUST_POLICY='{
  "Version":"2012-10-17",		 	 	 
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}'

echo "$TRUST_POLICY" > trust-policy.json

ROLE_OUTPUT=$(log_cmd "aws iam create-role --role-name \"$ROLE_NAME\" --assume-role-policy-document file://trust-policy.json --output json")
check_error "$ROLE_OUTPUT" $? "Failed to create IAM role"

ROLE_ARN=$(echo "$ROLE_OUTPUT" | grep -o '"Arn": "[^"]*' | cut -d'"' -f4)
echo "Role ARN: $ROLE_ARN" | tee -a "$LOG_FILE"

# Attach Lambda basic execution policy to the role
echo "Attaching Lambda execution policy to role..." | tee -a "$LOG_FILE"
POLICY_OUTPUT=$(log_cmd "aws iam attach-role-policy --role-name \"$ROLE_NAME\" --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole")
check_error "$POLICY_OUTPUT" $? "Failed to attach policy to role"

# Wait for role to propagate
echo "Waiting for IAM role to propagate..." | tee -a "$LOG_FILE"
sleep 10

# Create simple Python Lambda function code
echo "Creating Lambda function code..." | tee -a "$LOG_FILE"
cat > lambda_function.py << 'EOF'
def handler(event, context):
    print("Lambda function executed successfully")
    return {
        'statusCode': 200,
        'body': 'Success'
    }
EOF

# Zip the Lambda function code
log_cmd "zip -j lambda_function.zip lambda_function.py"

# Create first Lambda function
echo "Creating first Lambda function: $LAMBDA_FUNCTION1..." | tee -a "$LOG_FILE"
LAMBDA1_OUTPUT=$(log_cmd "aws lambda create-function --function-name \"$LAMBDA_FUNCTION1\" --runtime python3.9 --role \"$ROLE_ARN\" --handler lambda_function.handler --zip-file fileb://lambda_function.zip")
check_error "$LAMBDA1_OUTPUT" $? "Failed to create first Lambda function"

# Create second Lambda function
echo "Creating second Lambda function: $LAMBDA_FUNCTION2..." | tee -a "$LOG_FILE"
LAMBDA2_OUTPUT=$(log_cmd "aws lambda create-function --function-name \"$LAMBDA_FUNCTION2\" --runtime python3.9 --role \"$ROLE_ARN\" --handler lambda_function.handler --zip-file fileb://lambda_function.zip")
check_error "$LAMBDA2_OUTPUT" $? "Failed to create second Lambda function"

# Invoke Lambda functions to generate some metrics
echo "Invoking Lambda functions to generate metrics..." | tee -a "$LOG_FILE"
log_cmd "aws lambda invoke --function-name \"$LAMBDA_FUNCTION1\" --payload '{}' /dev/null"
log_cmd "aws lambda invoke --function-name \"$LAMBDA_FUNCTION2\" --payload '{}' /dev/null"

# Create CloudWatch dashboard with property variable
echo "Creating CloudWatch dashboard with property variable..." | tee -a "$LOG_FILE"

# Create a simpler dashboard with a property variable
# This approach uses a more basic dashboard structure that's known to work with the CloudWatch API
DASHBOARD_BODY=$(cat <<EOF
{
  "widgets": [
    {
      "type": "metric",
      "x": 0,
      "y": 0,
      "width": 12,
      "height": 6,
      "properties": {
        "metrics": [
          [ "AWS/Lambda", "Invocations", "FunctionName", "$LAMBDA_FUNCTION1" ]
        ],
        "view": "timeSeries",
        "stacked": false,
        "region": "$AWS_REGION",
        "title": "Lambda Invocations",
        "period": 300,
        "stat": "Sum"
      }
    }
  ]
}
EOF
)

# First create a basic dashboard without variables
echo "Creating initial dashboard without variables..." | tee -a "$LOG_FILE"
DASHBOARD_OUTPUT=$(log_cmd "aws cloudwatch put-dashboard --dashboard-name \"$DASHBOARD_NAME\" --dashboard-body '$DASHBOARD_BODY'")
check_error "$DASHBOARD_OUTPUT" $? "Failed to create initial CloudWatch dashboard"

# Now let's try to add a property variable using the console instructions
echo "To complete the tutorial, please follow these steps in the CloudWatch console:" | tee -a "$LOG_FILE"
echo "1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/" | tee -a "$LOG_FILE"
echo "2. Navigate to Dashboards and select your dashboard: $DASHBOARD_NAME" | tee -a "$LOG_FILE"
echo "3. Choose Actions > Variables > Create a variable" | tee -a "$LOG_FILE"
echo "4. Choose Property variable" | tee -a "$LOG_FILE"
echo "5. For Property that the variable changes, choose FunctionName" | tee -a "$LOG_FILE"
echo "6. For Input type, choose Select menu (dropdown)" | tee -a "$LOG_FILE"
echo "7. Choose Use the results of a metric search" | tee -a "$LOG_FILE"
echo "8. Choose Pre-built queries > Lambda > Errors" | tee -a "$LOG_FILE"
echo "9. Choose By Function Name and then choose Search" | tee -a "$LOG_FILE"
echo "10. (Optional) Configure any secondary settings as desired" | tee -a "$LOG_FILE"
echo "11. Choose Add variable" | tee -a "$LOG_FILE"
echo "" | tee -a "$LOG_FILE"
echo "The dashboard has been created and can be accessed at:" | tee -a "$LOG_FILE"
echo "https://console.aws.amazon.com/cloudwatch/home#dashboards:name=$DASHBOARD_NAME" | tee -a "$LOG_FILE"

# Verify dashboard creation
echo "Verifying dashboard creation..." | tee -a "$LOG_FILE"
VERIFY_OUTPUT=$(log_cmd "aws cloudwatch get-dashboard --dashboard-name \"$DASHBOARD_NAME\"")
check_error "$VERIFY_OUTPUT" $? "Failed to verify dashboard creation"

echo "" | tee -a "$LOG_FILE"
echo "==========================================" | tee -a "$LOG_FILE"
echo "DASHBOARD CREATED SUCCESSFULLY" | tee -a "$LOG_FILE"
echo "==========================================" | tee -a "$LOG_FILE"
echo "Dashboard Name: $DASHBOARD_NAME" | tee -a "$LOG_FILE"
echo "Lambda Functions: $LAMBDA_FUNCTION1, $LAMBDA_FUNCTION2" | tee -a "$LOG_FILE"
echo "" | tee -a "$LOG_FILE"
echo "You can view your dashboard in the CloudWatch console:" | tee -a "$LOG_FILE"
echo "https://console.aws.amazon.com/cloudwatch/home#dashboards:name=$DASHBOARD_NAME" | tee -a "$LOG_FILE"
echo "" | tee -a "$LOG_FILE"

# Prompt for cleanup
confirm_cleanup

echo "Script completed successfully." | tee -a "$LOG_FILE"
exit 0
```
+ For API details, see the following topics in *AWS CLI Command Reference*.
  + [AttachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/AttachRolePolicy)
  + [CreateFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/CreateFunction)
  + [CreateRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/CreateRole)
  + [DeleteDashboards](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/DeleteDashboards)
  + [DeleteFunction](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/DeleteFunction)
  + [DeleteRole](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DeleteRole)
  + [DetachRolePolicy](https://docs.aws.amazon.com/goto/aws-cli/iam-2010-05-08/DetachRolePolicy)
  + [GetDashboard](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/GetDashboard)
  + [Invoke](https://docs.aws.amazon.com/goto/aws-cli/lambda-2015-03-31/Invoke)
  + [PutDashboard](https://docs.aws.amazon.com/goto/aws-cli/monitoring-2010-08-01/PutDashboard)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Write custom activity data with a Lambda function after Amazon Cognito user authentication using an AWS SDK
<a name="example_cross_CognitoCustomActivityLog_section"></a>

The following code example shows how to write custom activity data with a Lambda function after Amazon Cognito user authentication.
+ Use administrator functions to add a user to a user pool.
+ Configure a user pool to call a Lambda function for the `PostAuthentication` trigger.
+ Sign the new user in to Amazon Cognito.
+ The Lambda function writes custom information to CloudWatch Logs and to an DynamoDB table.
+ Get and display custom data from the DynamoDB table, then clean up resources.

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/workflows/user_pools_and_lambda_triggers#code-examples). 
Run an interactive scenario at a command prompt.  

```
import (
	"context"
	"errors"
	"log"
	"strings"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// ActivityLog separates the steps of this scenario into individual functions so that
// they are simpler to read and understand.
type ActivityLog struct {
	helper       IScenarioHelper
	questioner   demotools.IQuestioner
	resources    Resources
	cognitoActor *actions.CognitoActions
}

// NewActivityLog constructs a new activity log runner.
func NewActivityLog(sdkConfig aws.Config, questioner demotools.IQuestioner, helper IScenarioHelper) ActivityLog {
	scenario := ActivityLog{
		helper:       helper,
		questioner:   questioner,
		resources:    Resources{},
		cognitoActor: &actions.CognitoActions{CognitoClient: cognitoidentityprovider.NewFromConfig(sdkConfig)},
	}
	scenario.resources.init(scenario.cognitoActor, questioner)
	return scenario
}

// AddUserToPool selects a user from the known users table and uses administrator credentials to add the user to the user pool.
func (runner *ActivityLog) AddUserToPool(ctx context.Context, userPoolId string, tableName string) (string, string) {
	log.Println("To facilitate this example, let's add a user to the user pool using administrator privileges.")
	users, err := runner.helper.GetKnownUsers(ctx, tableName)
	if err != nil {
		panic(err)
	}
	user := users.Users[0]
	log.Printf("Adding known user %v to the user pool.\n", user.UserName)
	err = runner.cognitoActor.AdminCreateUser(ctx, userPoolId, user.UserName, user.UserEmail)
	if err != nil {
		panic(err)
	}
	pwSet := false
	password := runner.questioner.AskPassword("\nEnter a password that has at least eight characters, uppercase, lowercase, numbers and symbols.\n"+
		"(the password will not display as you type):", 8)
	for !pwSet {
		log.Printf("\nSetting password for user '%v'.\n", user.UserName)
		err = runner.cognitoActor.AdminSetUserPassword(ctx, userPoolId, user.UserName, password)
		if err != nil {
			var invalidPassword *types.InvalidPasswordException
			if errors.As(err, &invalidPassword) {
				password = runner.questioner.AskPassword("\nEnter another password:", 8)
			} else {
				panic(err)
			}
		} else {
			pwSet = true
		}
	}

	log.Println(strings.Repeat("-", 88))

	return user.UserName, password
}

// AddActivityLogTrigger adds a Lambda handler as an invocation target for the PostAuthentication trigger.
func (runner *ActivityLog) AddActivityLogTrigger(ctx context.Context, userPoolId string, activityLogArn string) {
	log.Println("Let's add a Lambda function to handle the PostAuthentication trigger from Cognito.\n" +
		"This trigger happens after a user is authenticated, and lets your function take action, such as logging\n" +
		"the outcome.")
	err := runner.cognitoActor.UpdateTriggers(
		ctx, userPoolId,
		actions.TriggerInfo{Trigger: actions.PostAuthentication, HandlerArn: aws.String(activityLogArn)})
	if err != nil {
		panic(err)
	}
	runner.resources.triggers = append(runner.resources.triggers, actions.PostAuthentication)
	log.Printf("Lambda function %v added to user pool %v to handle PostAuthentication Cognito trigger.\n",
		activityLogArn, userPoolId)

	log.Println(strings.Repeat("-", 88))
}

// SignInUser signs in as the specified user.
func (runner *ActivityLog) SignInUser(ctx context.Context, clientId string, userName string, password string) {
	log.Printf("Now we'll sign in user %v and check the results in the logs and the DynamoDB table.", userName)
	runner.questioner.Ask("Press Enter when you're ready.")
	authResult, err := runner.cognitoActor.SignIn(ctx, clientId, userName, password)
	if err != nil {
		panic(err)
	}
	log.Println("Sign in successful.",
		"The PostAuthentication Lambda handler writes custom information to CloudWatch Logs.")

	runner.resources.userAccessTokens = append(runner.resources.userAccessTokens, *authResult.AccessToken)
}

// GetKnownUserLastLogin gets the login info for a user from the Amazon DynamoDB table and displays it.
func (runner *ActivityLog) GetKnownUserLastLogin(ctx context.Context, tableName string, userName string) {
	log.Println("The PostAuthentication handler also writes login data to the DynamoDB table.")
	runner.questioner.Ask("Press Enter when you're ready to continue.")
	users, err := runner.helper.GetKnownUsers(ctx, tableName)
	if err != nil {
		panic(err)
	}
	for _, user := range users.Users {
		if user.UserName == userName {
			log.Println("The last login info for the user in the known users table is:")
			log.Printf("\t%+v", *user.LastLogin)
		}
	}
	log.Println(strings.Repeat("-", 88))
}

// Run runs the scenario.
func (runner *ActivityLog) Run(ctx context.Context, stackName string) {
	defer func() {
		if r := recover(); r != nil {
			log.Println("Something went wrong with the demo.")
			runner.resources.Cleanup(ctx)
		}
	}()

	log.Println(strings.Repeat("-", 88))
	log.Printf("Welcome\n")

	log.Println(strings.Repeat("-", 88))

	stackOutputs, err := runner.helper.GetStackOutputs(ctx, stackName)
	if err != nil {
		panic(err)
	}
	runner.resources.userPoolId = stackOutputs["UserPoolId"]
	runner.helper.PopulateUserTable(ctx, stackOutputs["TableName"])
	userName, password := runner.AddUserToPool(ctx, stackOutputs["UserPoolId"], stackOutputs["TableName"])

	runner.AddActivityLogTrigger(ctx, stackOutputs["UserPoolId"], stackOutputs["ActivityLogFunctionArn"])
	runner.SignInUser(ctx, stackOutputs["UserPoolClientId"], userName, password)
	runner.helper.ListRecentLogEvents(ctx, stackOutputs["ActivityLogFunction"])
	runner.GetKnownUserLastLogin(ctx, stackOutputs["TableName"], userName)

	runner.resources.Cleanup(ctx)

	log.Println(strings.Repeat("-", 88))
	log.Println("Thanks for watching!")
	log.Println(strings.Repeat("-", 88))
}
```
Handle the `PostAuthentication` trigger with a Lambda function.  

```
import (
	"context"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	dynamodbtypes "github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)

const TABLE_NAME = "TABLE_NAME"

// LoginInfo defines structured login data that can be marshalled to a DynamoDB format.
type LoginInfo struct {
	UserPoolId string `dynamodbav:"UserPoolId"`
	ClientId   string `dynamodbav:"ClientId"`
	Time       string `dynamodbav:"Time"`
}

// UserInfo defines structured user data that can be marshalled to a DynamoDB format.
type UserInfo struct {
	UserName  string    `dynamodbav:"UserName"`
	UserEmail string    `dynamodbav:"UserEmail"`
	LastLogin LoginInfo `dynamodbav:"LastLogin"`
}

// GetKey marshals the user email value to a DynamoDB key format.
func (user UserInfo) GetKey() map[string]dynamodbtypes.AttributeValue {
	userEmail, err := attributevalue.Marshal(user.UserEmail)
	if err != nil {
		panic(err)
	}
	return map[string]dynamodbtypes.AttributeValue{"UserEmail": userEmail}
}

type handler struct {
	dynamoClient *dynamodb.Client
}

// HandleRequest handles the PostAuthentication event by writing custom data to the logs and
// to an Amazon DynamoDB table.
func (h *handler) HandleRequest(ctx context.Context, event events.CognitoEventUserPoolsPostAuthentication) (events.CognitoEventUserPoolsPostAuthentication, error) {
	log.Printf("Received post authentication trigger from %v for user '%v'", event.TriggerSource, event.UserName)
	tableName := os.Getenv(TABLE_NAME)
	user := UserInfo{
		UserName:  event.UserName,
		UserEmail: event.Request.UserAttributes["email"],
		LastLogin: LoginInfo{
			UserPoolId: event.UserPoolID,
			ClientId:   event.CallerContext.ClientID,
			Time:       time.Now().Format(time.UnixDate),
		},
	}
	// Write to CloudWatch Logs.
	fmt.Printf("%#v", user)

	// Also write to an external system. This examples uses DynamoDB to demonstrate.
	userMap, err := attributevalue.MarshalMap(user)
	if err != nil {
		log.Printf("Couldn't marshal to DynamoDB map. Here's why: %v\n", err)
	} else if len(userMap) == 0 {
		log.Printf("User info marshaled to an empty map.")
	} else {
		_, err := h.dynamoClient.PutItem(ctx, &dynamodb.PutItemInput{
			Item:      userMap,
			TableName: aws.String(tableName),
		})
		if err != nil {
			log.Printf("Couldn't write to DynamoDB. Here's why: %v\n", err)
		} else {
			log.Printf("Wrote user info to DynamoDB table %v.\n", tableName)
		}
	}

	return event, nil
}

func main() {
	ctx := context.Background()
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		log.Panicln(err)
	}
	h := handler{
		dynamoClient: dynamodb.NewFromConfig(sdkConfig),
	}
	lambda.Start(h.HandleRequest)
}
```
Create a struct that performs common tasks.  

```
import (
	"context"
	"log"
	"strings"
	"time"
	"user_pools_and_lambda_triggers/actions"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// IScenarioHelper defines common functions used by the workflows in this example.
type IScenarioHelper interface {
	Pause(secs int)
	GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error)
	PopulateUserTable(ctx context.Context, tableName string)
	GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error)
	AddKnownUser(ctx context.Context, tableName string, user actions.User)
	ListRecentLogEvents(ctx context.Context, functionName string)
}

// ScenarioHelper contains AWS wrapper structs used by the workflows in this example.
type ScenarioHelper struct {
	questioner  demotools.IQuestioner
	dynamoActor *actions.DynamoActions
	cfnActor    *actions.CloudFormationActions
	cwlActor    *actions.CloudWatchLogsActions
	isTestRun   bool
}

// NewScenarioHelper constructs a new scenario helper.
func NewScenarioHelper(sdkConfig aws.Config, questioner demotools.IQuestioner) ScenarioHelper {
	scenario := ScenarioHelper{
		questioner:  questioner,
		dynamoActor: &actions.DynamoActions{DynamoClient: dynamodb.NewFromConfig(sdkConfig)},
		cfnActor:    &actions.CloudFormationActions{CfnClient: cloudformation.NewFromConfig(sdkConfig)},
		cwlActor:    &actions.CloudWatchLogsActions{CwlClient: cloudwatchlogs.NewFromConfig(sdkConfig)},
	}
	return scenario
}

// Pause waits for the specified number of seconds.
func (helper ScenarioHelper) Pause(secs int) {
	if !helper.isTestRun {
		time.Sleep(time.Duration(secs) * time.Second)
	}
}

// GetStackOutputs gets the outputs from the specified CloudFormation stack in a structured format.
func (helper ScenarioHelper) GetStackOutputs(ctx context.Context, stackName string) (actions.StackOutputs, error) {
	return helper.cfnActor.GetOutputs(ctx, stackName), nil
}

// PopulateUserTable fills the known user table with example data.
func (helper ScenarioHelper) PopulateUserTable(ctx context.Context, tableName string) {
	log.Printf("First, let's add some users to the DynamoDB %v table we'll use for this example.\n", tableName)
	err := helper.dynamoActor.PopulateTable(ctx, tableName)
	if err != nil {
		panic(err)
	}
}

// GetKnownUsers gets the users from the known users table in a structured format.
func (helper ScenarioHelper) GetKnownUsers(ctx context.Context, tableName string) (actions.UserList, error) {
	knownUsers, err := helper.dynamoActor.Scan(ctx, tableName)
	if err != nil {
		log.Printf("Couldn't get known users from table %v. Here's why: %v\n", tableName, err)
	}
	return knownUsers, err
}

// AddKnownUser adds a user to the known users table.
func (helper ScenarioHelper) AddKnownUser(ctx context.Context, tableName string, user actions.User) {
	log.Printf("Adding user '%v' with email '%v' to the DynamoDB known users table...\n",
		user.UserName, user.UserEmail)
	err := helper.dynamoActor.AddUser(ctx, tableName, user)
	if err != nil {
		panic(err)
	}
}

// ListRecentLogEvents gets the most recent log stream and events for the specified Lambda function and displays them.
func (helper ScenarioHelper) ListRecentLogEvents(ctx context.Context, functionName string) {
	log.Println("Waiting a few seconds to let Lambda write to CloudWatch Logs...")
	helper.Pause(10)
	log.Println("Okay, let's check the logs to find what's happened recently with your Lambda function.")
	logStream, err := helper.cwlActor.GetLatestLogStream(ctx, functionName)
	if err != nil {
		panic(err)
	}
	log.Printf("Getting some recent events from log stream %v\n", *logStream.LogStreamName)
	events, err := helper.cwlActor.GetLogEvents(ctx, functionName, *logStream.LogStreamName, 10)
	if err != nil {
		panic(err)
	}
	for _, event := range events {
		log.Printf("\t%v", *event.Message)
	}
	log.Println(strings.Repeat("-", 88))
}
```
Create a struct that wraps Amazon Cognito actions.  

```
import (
	"context"
	"errors"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider"
	"github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
)

type CognitoActions struct {
	CognitoClient *cognitoidentityprovider.Client
}



// Trigger and TriggerInfo define typed data for updating an Amazon Cognito trigger.
type Trigger int

const (
	PreSignUp Trigger = iota
	UserMigration
	PostAuthentication
)

type TriggerInfo struct {
	Trigger    Trigger
	HandlerArn *string
}

// UpdateTriggers adds or removes Lambda triggers for a user pool. When a trigger is specified with a `nil` value,
// it is removed from the user pool.
func (actor CognitoActions) UpdateTriggers(ctx context.Context, userPoolId string, triggers ...TriggerInfo) error {
	output, err := actor.CognitoClient.DescribeUserPool(ctx, &cognitoidentityprovider.DescribeUserPoolInput{
		UserPoolId: aws.String(userPoolId),
	})
	if err != nil {
		log.Printf("Couldn't get info about user pool %v. Here's why: %v\n", userPoolId, err)
		return err
	}
	lambdaConfig := output.UserPool.LambdaConfig
	for _, trigger := range triggers {
		switch trigger.Trigger {
		case PreSignUp:
			lambdaConfig.PreSignUp = trigger.HandlerArn
		case UserMigration:
			lambdaConfig.UserMigration = trigger.HandlerArn
		case PostAuthentication:
			lambdaConfig.PostAuthentication = trigger.HandlerArn
		}
	}
	_, err = actor.CognitoClient.UpdateUserPool(ctx, &cognitoidentityprovider.UpdateUserPoolInput{
		UserPoolId:   aws.String(userPoolId),
		LambdaConfig: lambdaConfig,
	})
	if err != nil {
		log.Printf("Couldn't update user pool %v. Here's why: %v\n", userPoolId, err)
	}
	return err
}



// SignUp signs up a user with Amazon Cognito.
func (actor CognitoActions) SignUp(ctx context.Context, clientId string, userName string, password string, userEmail string) (bool, error) {
	confirmed := false
	output, err := actor.CognitoClient.SignUp(ctx, &cognitoidentityprovider.SignUpInput{
		ClientId: aws.String(clientId),
		Password: aws.String(password),
		Username: aws.String(userName),
		UserAttributes: []types.AttributeType{
			{Name: aws.String("email"), Value: aws.String(userEmail)},
		},
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't sign up user %v. Here's why: %v\n", userName, err)
		}
	} else {
		confirmed = output.UserConfirmed
	}
	return confirmed, err
}



// SignIn signs in a user to Amazon Cognito using a username and password authentication flow.
func (actor CognitoActions) SignIn(ctx context.Context, clientId string, userName string, password string) (*types.AuthenticationResultType, error) {
	var authResult *types.AuthenticationResultType
	output, err := actor.CognitoClient.InitiateAuth(ctx, &cognitoidentityprovider.InitiateAuthInput{
		AuthFlow:       "USER_PASSWORD_AUTH",
		ClientId:       aws.String(clientId),
		AuthParameters: map[string]string{"USERNAME": userName, "PASSWORD": password},
	})
	if err != nil {
		var resetRequired *types.PasswordResetRequiredException
		if errors.As(err, &resetRequired) {
			log.Println(*resetRequired.Message)
		} else {
			log.Printf("Couldn't sign in user %v. Here's why: %v\n", userName, err)
		}
	} else {
		authResult = output.AuthenticationResult
	}
	return authResult, err
}



// ForgotPassword starts a password recovery flow for a user. This flow typically sends a confirmation code
// to the user's configured notification destination, such as email.
func (actor CognitoActions) ForgotPassword(ctx context.Context, clientId string, userName string) (*types.CodeDeliveryDetailsType, error) {
	output, err := actor.CognitoClient.ForgotPassword(ctx, &cognitoidentityprovider.ForgotPasswordInput{
		ClientId: aws.String(clientId),
		Username: aws.String(userName),
	})
	if err != nil {
		log.Printf("Couldn't start password reset for user '%v'. Here;s why: %v\n", userName, err)
	}
	return output.CodeDeliveryDetails, err
}



// ConfirmForgotPassword confirms a user with a confirmation code and a new password.
func (actor CognitoActions) ConfirmForgotPassword(ctx context.Context, clientId string, code string, userName string, password string) error {
	_, err := actor.CognitoClient.ConfirmForgotPassword(ctx, &cognitoidentityprovider.ConfirmForgotPasswordInput{
		ClientId:         aws.String(clientId),
		ConfirmationCode: aws.String(code),
		Password:         aws.String(password),
		Username:         aws.String(userName),
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't confirm user %v. Here's why: %v", userName, err)
		}
	}
	return err
}



// DeleteUser removes a user from the user pool.
func (actor CognitoActions) DeleteUser(ctx context.Context, userAccessToken string) error {
	_, err := actor.CognitoClient.DeleteUser(ctx, &cognitoidentityprovider.DeleteUserInput{
		AccessToken: aws.String(userAccessToken),
	})
	if err != nil {
		log.Printf("Couldn't delete user. Here's why: %v\n", err)
	}
	return err
}



// AdminCreateUser uses administrator credentials to add a user to a user pool. This method leaves the user
// in a state that requires they enter a new password next time they sign in.
func (actor CognitoActions) AdminCreateUser(ctx context.Context, userPoolId string, userName string, userEmail string) error {
	_, err := actor.CognitoClient.AdminCreateUser(ctx, &cognitoidentityprovider.AdminCreateUserInput{
		UserPoolId:     aws.String(userPoolId),
		Username:       aws.String(userName),
		MessageAction:  types.MessageActionTypeSuppress,
		UserAttributes: []types.AttributeType{{Name: aws.String("email"), Value: aws.String(userEmail)}},
	})
	if err != nil {
		var userExists *types.UsernameExistsException
		if errors.As(err, &userExists) {
			log.Printf("User %v already exists in the user pool.", userName)
			err = nil
		} else {
			log.Printf("Couldn't create user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}



// AdminSetUserPassword uses administrator credentials to set a password for a user without requiring a
// temporary password.
func (actor CognitoActions) AdminSetUserPassword(ctx context.Context, userPoolId string, userName string, password string) error {
	_, err := actor.CognitoClient.AdminSetUserPassword(ctx, &cognitoidentityprovider.AdminSetUserPasswordInput{
		Password:   aws.String(password),
		UserPoolId: aws.String(userPoolId),
		Username:   aws.String(userName),
		Permanent:  true,
	})
	if err != nil {
		var invalidPassword *types.InvalidPasswordException
		if errors.As(err, &invalidPassword) {
			log.Println(*invalidPassword.Message)
		} else {
			log.Printf("Couldn't set password for user %v. Here's why: %v\n", userName, err)
		}
	}
	return err
}
```
Create a struct that wraps DynamoDB actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb"
	"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)

// DynamoActions encapsulates the Amazon Simple Notification Service (Amazon SNS) actions
// used in the examples.
type DynamoActions struct {
	DynamoClient *dynamodb.Client
}

// User defines structured user data.
type User struct {
	UserName  string
	UserEmail string
	LastLogin *LoginInfo `dynamodbav:",omitempty"`
}

// LoginInfo defines structured custom login data.
type LoginInfo struct {
	UserPoolId string
	ClientId   string
	Time       string
}

// UserList defines a list of users.
type UserList struct {
	Users []User
}

// UserNameList returns the usernames contained in a UserList as a list of strings.
func (users *UserList) UserNameList() []string {
	names := make([]string, len(users.Users))
	for i := 0; i < len(users.Users); i++ {
		names[i] = users.Users[i].UserName
	}
	return names
}

// PopulateTable adds a set of test users to the table.
func (actor DynamoActions) PopulateTable(ctx context.Context, tableName string) error {
	var err error
	var item map[string]types.AttributeValue
	var writeReqs []types.WriteRequest
	for i := 1; i < 4; i++ {
		item, err = attributevalue.MarshalMap(User{UserName: fmt.Sprintf("test_user_%v", i), UserEmail: fmt.Sprintf("test_email_%v@example.com", i)})
		if err != nil {
			log.Printf("Couldn't marshall user into DynamoDB format. Here's why: %v\n", err)
			return err
		}
		writeReqs = append(writeReqs, types.WriteRequest{PutRequest: &types.PutRequest{Item: item}})
	}
	_, err = actor.DynamoClient.BatchWriteItem(ctx, &dynamodb.BatchWriteItemInput{
		RequestItems: map[string][]types.WriteRequest{tableName: writeReqs},
	})
	if err != nil {
		log.Printf("Couldn't populate table %v with users. Here's why: %v\n", tableName, err)
	}
	return err
}

// Scan scans the table for all items.
func (actor DynamoActions) Scan(ctx context.Context, tableName string) (UserList, error) {
	var userList UserList
	output, err := actor.DynamoClient.Scan(ctx, &dynamodb.ScanInput{
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't scan table %v for items. Here's why: %v\n", tableName, err)
	} else {
		err = attributevalue.UnmarshalListOfMaps(output.Items, &userList.Users)
		if err != nil {
			log.Printf("Couldn't unmarshal items into users. Here's why: %v\n", err)
		}
	}
	return userList, err
}

// AddUser adds a user item to a table.
func (actor DynamoActions) AddUser(ctx context.Context, tableName string, user User) error {
	userItem, err := attributevalue.MarshalMap(user)
	if err != nil {
		log.Printf("Couldn't marshall user to item. Here's why: %v\n", err)
	}
	_, err = actor.DynamoClient.PutItem(ctx, &dynamodb.PutItemInput{
		Item:      userItem,
		TableName: aws.String(tableName),
	})
	if err != nil {
		log.Printf("Couldn't put item in table %v. Here's why: %v", tableName, err)
	}
	return err
}
```
Create a struct that wraps CloudWatch Logs actions.  

```
import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs"
	"github.com/aws/aws-sdk-go-v2/service/cloudwatchlogs/types"
)

type CloudWatchLogsActions struct {
	CwlClient *cloudwatchlogs.Client
}

// GetLatestLogStream gets the most recent log stream for a Lambda function.
func (actor CloudWatchLogsActions) GetLatestLogStream(ctx context.Context, functionName string) (types.LogStream, error) {
	var logStream types.LogStream
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.DescribeLogStreams(ctx, &cloudwatchlogs.DescribeLogStreamsInput{
		Descending:   aws.Bool(true),
		Limit:        aws.Int32(1),
		LogGroupName: aws.String(logGroupName),
		OrderBy:      types.OrderByLastEventTime,
	})
	if err != nil {
		log.Printf("Couldn't get log streams for log group %v. Here's why: %v\n", logGroupName, err)
	} else {
		logStream = output.LogStreams[0]
	}
	return logStream, err
}

// GetLogEvents gets the most recent eventCount events from the specified log stream.
func (actor CloudWatchLogsActions) GetLogEvents(ctx context.Context, functionName string, logStreamName string, eventCount int32) (
	[]types.OutputLogEvent, error) {
	var events []types.OutputLogEvent
	logGroupName := fmt.Sprintf("/aws/lambda/%s", functionName)
	output, err := actor.CwlClient.GetLogEvents(ctx, &cloudwatchlogs.GetLogEventsInput{
		LogStreamName: aws.String(logStreamName),
		Limit:         aws.Int32(eventCount),
		LogGroupName:  aws.String(logGroupName),
	})
	if err != nil {
		log.Printf("Couldn't get log event for log stream %v. Here's why: %v\n", logStreamName, err)
	} else {
		events = output.Events
	}
	return events, err
}
```
Create a struct that wraps CloudFormation actions.  

```
import (
	"context"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/cloudformation"
)

// StackOutputs defines a map of outputs from a specific stack.
type StackOutputs map[string]string

type CloudFormationActions struct {
	CfnClient *cloudformation.Client
}

// GetOutputs gets the outputs from a CloudFormation stack and puts them into a structured format.
func (actor CloudFormationActions) GetOutputs(ctx context.Context, stackName string) StackOutputs {
	output, err := actor.CfnClient.DescribeStacks(ctx, &cloudformation.DescribeStacksInput{
		StackName: aws.String(stackName),
	})
	if err != nil || len(output.Stacks) == 0 {
		log.Panicf("Couldn't find a CloudFormation stack named %v. Here's why: %v\n", stackName, err)
	}
	stackOutputs := StackOutputs{}
	for _, out := range output.Stacks[0].Outputs {
		stackOutputs[*out.OutputKey] = *out.OutputValue
	}
	return stackOutputs
}
```
Clean up resources.  

```
import (
	"context"
	"log"
	"user_pools_and_lambda_triggers/actions"

	"github.com/awsdocs/aws-doc-sdk-examples/gov2/demotools"
)

// Resources keeps track of AWS resources created during an example and handles
// cleanup when the example finishes.
type Resources struct {
	userPoolId       string
	userAccessTokens []string
	triggers         []actions.Trigger

	cognitoActor *actions.CognitoActions
	questioner   demotools.IQuestioner
}

func (resources *Resources) init(cognitoActor *actions.CognitoActions, questioner demotools.IQuestioner) {
	resources.userAccessTokens = []string{}
	resources.triggers = []actions.Trigger{}
	resources.cognitoActor = cognitoActor
	resources.questioner = questioner
}

// Cleanup deletes all AWS resources created during an example.
func (resources *Resources) Cleanup(ctx context.Context) {
	defer func() {
		if r := recover(); r != nil {
			log.Printf("Something went wrong during cleanup.\n%v\n", r)
			log.Println("Use the AWS Management Console to remove any remaining resources \n" +
				"that were created for this scenario.")
		}
	}()

	wantDelete := resources.questioner.AskBool("Do you want to remove all of the AWS resources that were created "+
		"during this demo (y/n)?", "y")
	if wantDelete {
		for _, accessToken := range resources.userAccessTokens {
			err := resources.cognitoActor.DeleteUser(ctx, accessToken)
			if err != nil {
				log.Println("Couldn't delete user during cleanup.")
				panic(err)
			}
			log.Println("Deleted user.")
		}
		triggerList := make([]actions.TriggerInfo, len(resources.triggers))
		for i := 0; i < len(resources.triggers); i++ {
			triggerList[i] = actions.TriggerInfo{Trigger: resources.triggers[i], HandlerArn: nil}
		}
		err := resources.cognitoActor.UpdateTriggers(ctx, resources.userPoolId, triggerList...)
		if err != nil {
			log.Println("Couldn't update Cognito triggers during cleanup.")
			panic(err)
		}
		log.Println("Removed Cognito triggers from user pool.")
	} else {
		log.Println("Be sure to remove resources when you're done with them to avoid unexpected charges!")
	}
}
```
+ For API details, see the following topics in *AWS SDK for Go API Reference*.
  + [AdminCreateUser](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.AdminCreateUser)
  + [AdminSetUserPassword](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.AdminSetUserPassword)
  + [DeleteUser](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.DeleteUser)
  + [InitiateAuth](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.InitiateAuth)
  + [UpdateUserPool](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider#Client.UpdateUserPool)

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Serverless examples for Lambda
<a name="service_code_examples_serverless_examples"></a>

The following code examples show how to use Lambda with AWS SDKs.

**Topics**
+ [Connecting to an Amazon RDS database in a Lambda function](example_serverless_connect_RDS_Lambda_section.md)
+ [Invoke a Lambda function from a Kinesis trigger](example_serverless_Kinesis_Lambda_section.md)
+ [Invoke a Lambda function from a DynamoDB trigger](example_serverless_DynamoDB_Lambda_section.md)
+ [Invoke a Lambda function from a Amazon DocumentDB trigger](example_serverless_DocumentDB_Lambda_section.md)
+ [Invoke a Lambda function from an Amazon MSK trigger](example_serverless_MSK_Lambda_section.md)
+ [Invoke a Lambda function from an Amazon S3 trigger](example_serverless_S3_Lambda_section.md)
+ [Invoke a Lambda function from an Amazon SNS trigger](example_serverless_SNS_Lambda_section.md)
+ [Invoke a Lambda function from an Amazon SQS trigger](example_serverless_SQS_Lambda_section.md)
+ [Reporting batch item failures for Lambda functions with a Kinesis trigger](example_serverless_Kinesis_Lambda_batch_item_failures_section.md)
+ [Reporting batch item failures for Lambda functions with a DynamoDB trigger](example_serverless_DynamoDB_Lambda_batch_item_failures_section.md)
+ [Reporting batch item failures for Lambda functions with an Amazon SQS trigger](example_serverless_SQS_Lambda_batch_item_failures_section.md)

# Connecting to an Amazon RDS database in a Lambda function
<a name="example_serverless_connect_RDS_Lambda_section"></a>

The following code examples show how to implement a Lambda function that connects to an RDS database. The function makes a simple database request and returns the result.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using .NET.  

```
using System.Data;
using System.Text.Json;
using Amazon.Lambda.APIGatewayEvents;
using Amazon.Lambda.Core;
using MySql.Data.MySqlClient;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace aws_rds;

public class InputModel
{
    public string key1 { get; set; }
    public string key2 { get; set; }
}

public class Function
{
    /// <summary>
    // Handles the Lambda function execution for connecting to RDS using IAM authentication.
    /// </summary>
    /// <param name="input">The input event data passed to the Lambda function</param>
    /// <param name="context">The Lambda execution context that provides runtime information</param>
    /// <returns>A response object containing the execution result</returns>

    public async Task<APIGatewayProxyResponse> FunctionHandler(APIGatewayProxyRequest request, ILambdaContext context)
    {
        // Sample Input: {"body": "{\"key1\":\"20\", \"key2\":\"25\"}"}
        var input = JsonSerializer.Deserialize<InputModel>(request.Body);

        /// Obtain authentication token
        var authToken = RDSAuthTokenGenerator.GenerateAuthToken(
            Environment.GetEnvironmentVariable("RDS_ENDPOINT"),
            Convert.ToInt32(Environment.GetEnvironmentVariable("RDS_PORT")),
            Environment.GetEnvironmentVariable("RDS_USERNAME")
        );

        /// Build the Connection String with the Token 
        string connectionString = $"Server={Environment.GetEnvironmentVariable("RDS_ENDPOINT")};" +
                                  $"Port={Environment.GetEnvironmentVariable("RDS_PORT")};" +
                                  $"Uid={Environment.GetEnvironmentVariable("RDS_USERNAME")};" +
                                  $"Pwd={authToken};";


        try
        {
            await using var connection = new MySqlConnection(connectionString);
            await connection.OpenAsync();

            const string sql = "SELECT @param1 + @param2 AS Sum";

            await using var command = new MySqlCommand(sql, connection);
            command.Parameters.AddWithValue("@param1", int.Parse(input.key1 ?? "0"));
            command.Parameters.AddWithValue("@param2", int.Parse(input.key2 ?? "0"));

            await using var reader = await command.ExecuteReaderAsync();
            if (await reader.ReadAsync())
            {
                int result = reader.GetInt32("Sum");

                //Sample Response: {"statusCode":200,"body":"{\"message\":\"The sum is: 45\"}","isBase64Encoded":false}
                return new APIGatewayProxyResponse
                {
                    StatusCode = 200,
                    Body = JsonSerializer.Serialize(new { message = $"The sum is: {result}" })
                };
            }

        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
        }

        return new APIGatewayProxyResponse
        {
            StatusCode = 500,
            Body = JsonSerializer.Serialize(new { error = "Internal server error" })
        };
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using Go.  

```
/*
Golang v2 code here.
*/

package main

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"os"

	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/feature/rds/auth"
	_ "github.com/go-sql-driver/mysql"
)

type MyEvent struct {
	Name string `json:"name"`
}

func HandleRequest(event *MyEvent) (map[string]interface{}, error) {

	var dbName string = os.Getenv("DatabaseName")
	var dbUser string = os.Getenv("DatabaseUser")
	var dbHost string = os.Getenv("DBHost") // Add hostname without https
	var dbPort int = os.Getenv("Port")      // Add port number
	var dbEndpoint string = fmt.Sprintf("%s:%d", dbHost, dbPort)
	var region string = os.Getenv("AWS_REGION")

	cfg, err := config.LoadDefaultConfig(context.TODO())
	if err != nil {
		panic("configuration error: " + err.Error())
	}

	authenticationToken, err := auth.BuildAuthToken(
		context.TODO(), dbEndpoint, region, dbUser, cfg.Credentials)
	if err != nil {
		panic("failed to create authentication token: " + err.Error())
	}

	dsn := fmt.Sprintf("%s:%s@tcp(%s)/%s?tls=true&allowCleartextPasswords=true",
		dbUser, authenticationToken, dbEndpoint, dbName,
	)

	db, err := sql.Open("mysql", dsn)
	if err != nil {
		panic(err)
	}

	defer db.Close()

	var sum int
	err = db.QueryRow("SELECT ?+? AS sum", 3, 2).Scan(&sum)
	if err != nil {
		panic(err)
	}
	s := fmt.Sprint(sum)
	message := fmt.Sprintf("The selected sum is: %s", s)

	messageBytes, err := json.Marshal(message)
	if err != nil {
		return nil, err
	}

	messageString := string(messageBytes)
	return map[string]interface{}{
		"statusCode": 200,
		"headers":    map[string]string{"Content-Type": "application/json"},
		"body":       messageString,
	}, nil
}

func main() {
	lambda.Start(HandleRequest)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using Java.  

```
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyRequestEvent;
import com.amazonaws.services.lambda.runtime.events.APIGatewayProxyResponseEvent;
import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.rdsdata.RdsDataClient;
import software.amazon.awssdk.services.rdsdata.model.ExecuteStatementRequest;
import software.amazon.awssdk.services.rdsdata.model.ExecuteStatementResponse;
import software.amazon.awssdk.services.rdsdata.model.Field;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class RdsLambdaHandler implements RequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {

    @Override
    public APIGatewayProxyResponseEvent handleRequest(APIGatewayProxyRequestEvent event, Context context) {
        APIGatewayProxyResponseEvent response = new APIGatewayProxyResponseEvent();

        try {
            // Obtain auth token
            String token = createAuthToken();

            // Define connection configuration
            String connectionString = String.format("jdbc:mysql://%s:%s/%s?useSSL=true&requireSSL=true",
                    System.getenv("ProxyHostName"),
                    System.getenv("Port"),
                    System.getenv("DBName"));

            // Establish a connection to the database
            try (Connection connection = DriverManager.getConnection(connectionString, System.getenv("DBUserName"), token);
                 PreparedStatement statement = connection.prepareStatement("SELECT ? + ? AS sum")) {

                statement.setInt(1, 3);
                statement.setInt(2, 2);

                try (ResultSet resultSet = statement.executeQuery()) {
                    if (resultSet.next()) {
                        int sum = resultSet.getInt("sum");
                        response.setStatusCode(200);
                        response.setBody("The selected sum is: " + sum);
                    }
                }
            }

        } catch (Exception e) {
            response.setStatusCode(500);
            response.setBody("Error: " + e.getMessage());
        }

        return response;
    }

    private String createAuthToken() {
        // Create RDS Data Service client
        RdsDataClient rdsDataClient = RdsDataClient.builder()
                .region(Region.of(System.getenv("AWS_REGION")))
                .credentialsProvider(DefaultCredentialsProvider.create())
                .build();

        // Define authentication request
        ExecuteStatementRequest request = ExecuteStatementRequest.builder()
                .resourceArn(System.getenv("ProxyHostName"))
                .secretArn(System.getenv("DBUserName"))
                .database(System.getenv("DBName"))
                .sql("SELECT 'RDS IAM Authentication'")
                .build();

        // Execute request and obtain authentication token
        ExecuteStatementResponse response = rdsDataClient.executeStatement(request);
        Field tokenField = response.records().get(0).get(0);

        return tokenField.stringValue();
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using JavaScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
/* 
Node.js code here.
*/
// ES6+ example
import { Signer } from "@aws-sdk/rds-signer";
import mysql from 'mysql2/promise';

async function createAuthToken() {
  // Define connection authentication parameters
  const dbinfo = {

    hostname: process.env.ProxyHostName,
    port: process.env.Port,
    username: process.env.DBUserName,
    region: process.env.AWS_REGION,

  }

  // Create RDS Signer object
  const signer = new Signer(dbinfo);

  // Request authorization token from RDS, specifying the username
  const token = await signer.getAuthToken();
  return token;
}

async function dbOps() {

  // Obtain auth token
  const token = await createAuthToken();
  // Define connection configuration
  let connectionConfig = {
    host: process.env.ProxyHostName,
    user: process.env.DBUserName,
    password: token,
    database: process.env.DBName,
    ssl: 'Amazon RDS'
  }
  // Create the connection to the DB
  const conn = await mysql.createConnection(connectionConfig);
  // Obtain the result of the query
  const [res,] = await conn.execute('select ?+? as sum', [3, 2]);
  return res;

}

export const handler = async (event) => {
  // Execute database flow
  const result = await dbOps();
  // Return result
  return {
    statusCode: 200,
    body: JSON.stringify("The selected sum is: " + result[0].sum)
  }
};
```
Connecting to an Amazon RDS database in a Lambda function using TypeScript.  

```
import { Signer } from "@aws-sdk/rds-signer";
import mysql from 'mysql2/promise';

// RDS settings
// Using '!' (non-null assertion operator) to tell the TypeScript compiler that the DB settings are not null or undefined,
const proxy_host_name = process.env.PROXY_HOST_NAME!
const port = parseInt(process.env.PORT!)
const db_name = process.env.DB_NAME!
const db_user_name = process.env.DB_USER_NAME!
const aws_region = process.env.AWS_REGION!


async function createAuthToken(): Promise<string> {

    // Create RDS Signer object
    const signer = new Signer({
        hostname: proxy_host_name,
        port: port,
        region: aws_region,
        username: db_user_name
    });

    // Request authorization token from RDS, specifying the username
    const token = await signer.getAuthToken();
    return token;
}

async function dbOps(): Promise<mysql.QueryResult | undefined> {
    try {
        // Obtain auth token
        const token = await createAuthToken();
        const conn = await mysql.createConnection({
            host: proxy_host_name,
            user: db_user_name,
            password: token,
            database: db_name,
            ssl: 'Amazon RDS' // Ensure you have the CA bundle for SSL connection
        });
        const [rows, fields] = await conn.execute('SELECT ? + ? AS sum', [3, 2]);
        console.log('result:', rows);
        return rows;
    }
    catch (err) {
        console.log(err);
    }
}

export const lambdaHandler = async (event: any): Promise<{ statusCode: number; body: string }> => {
    // Execute database flow
    const result = await dbOps();

    // Return error is result is undefined
    if (result == undefined)
        return {
            statusCode: 500,
            body: JSON.stringify(`Error with connection to DB host`)
        }

    // Return result
    return {
        statusCode: 200,
        body: JSON.stringify(`The selected sum is: ${result[0].sum}`)
    };
};
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using PHP.  

```
<?php
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\Handler as StdHandler;
use Bref\Logger\StderrLogger;
use Aws\Rds\AuthTokenGenerator;
use Aws\Credentials\CredentialProvider;

require __DIR__ . '/vendor/autoload.php';

class Handler implements StdHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }


    private function getAuthToken(): string {
        // Define connection authentication parameters
        $dbConnection = [
            'hostname' => getenv('DB_HOSTNAME'),
            'port' => getenv('DB_PORT'),
            'username' => getenv('DB_USERNAME'),
            'region' => getenv('AWS_REGION'),
        ];

        // Create RDS AuthTokenGenerator object
        $generator = new AuthTokenGenerator(CredentialProvider::defaultProvider());

        // Request authorization token from RDS, specifying the username
        return $generator->createToken(
            $dbConnection['hostname'] . ':' . $dbConnection['port'],
            $dbConnection['region'],
            $dbConnection['username']
        );
    }

    private function getQueryResults() {
        // Obtain auth token
        $token = $this->getAuthToken();

        // Define connection configuration
        $connectionConfig = [
            'host' => getenv('DB_HOSTNAME'),
            'user' => getenv('DB_USERNAME'),
            'password' => $token,
            'database' => getenv('DB_NAME'),
        ];

        // Create the connection to the DB
        $conn = new PDO(
            "mysql:host={$connectionConfig['host']};dbname={$connectionConfig['database']}",
            $connectionConfig['user'],
            $connectionConfig['password'],
            [
                PDO::MYSQL_ATTR_SSL_CA => '/path/to/rds-ca-2019-root.pem',
                PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT => true,
            ]
        );

        // Obtain the result of the query
        $stmt = $conn->prepare('SELECT ?+? AS sum');
        $stmt->execute([3, 2]);

        return $stmt->fetch(PDO::FETCH_ASSOC);
    }

    /**
     * @param mixed $event
     * @param Context $context
     * @return array
     */
    public function handle(mixed $event, Context $context): array
    {
        $this->logger->info("Processing query");

        // Execute database flow
        $result = $this->getQueryResults();

        return [
            'sum' => $result['sum']
        ];
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using Python.  

```
import json
import os
import boto3
import pymysql

# RDS settings
proxy_host_name = os.environ['PROXY_HOST_NAME']
port = int(os.environ['PORT'])
db_name = os.environ['DB_NAME']
db_user_name = os.environ['DB_USER_NAME']
aws_region = os.environ['AWS_REGION']


# Fetch RDS Auth Token
def get_auth_token():
    client = boto3.client('rds')
    token = client.generate_db_auth_token(
        DBHostname=proxy_host_name,
        Port=port
        DBUsername=db_user_name
        Region=aws_region
    )
    return token

def lambda_handler(event, context):
    token = get_auth_token()
    try:
        connection = pymysql.connect(
            host=proxy_host_name,
            user=db_user_name,
            password=token,
            db=db_name,
            port=port,
            ssl={'ca': 'Amazon RDS'}  # Ensure you have the CA bundle for SSL connection
        )
        
        with connection.cursor() as cursor:
            cursor.execute('SELECT %s + %s AS sum', (3, 2))
            result = cursor.fetchone()

        return result
        
    except Exception as e:
        return (f"Error: {str(e)}")  # Return an error message if an exception occurs
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using Ruby.  

```
# Ruby code here.

require 'aws-sdk-rds'
require 'json'
require 'mysql2'

def lambda_handler(event:, context:)
  endpoint = ENV['DBEndpoint'] # Add the endpoint without https"
  port = ENV['Port']           # 3306
  user = ENV['DBUser']
  region = ENV['DBRegion']     # 'us-east-1'
  db_name = ENV['DBName']

  credentials = Aws::Credentials.new(
    ENV['AWS_ACCESS_KEY_ID'],
    ENV['AWS_SECRET_ACCESS_KEY'],
    ENV['AWS_SESSION_TOKEN']
  )
  rds_client = Aws::RDS::AuthTokenGenerator.new(
    region: region, 
    credentials: credentials
  )

  token = rds_client.auth_token(
    endpoint: endpoint+ ':' + port,
    user_name: user,
    region: region
  )

  begin
    conn = Mysql2::Client.new(
      host: endpoint,
      username: user,
      password: token,
      port: port,
      database: db_name,
      sslca: '/var/task/global-bundle.pem', 
      sslverify: true,
      enable_cleartext_plugin: true
    )
    a = 3
    b = 2
    result = conn.query("SELECT #{a} + #{b} AS sum").first['sum']
    puts result
    conn.close
    {
      statusCode: 200,
      body: result.to_json
    }
  rescue => e
    puts "Database connection failed due to #{e}"
  end
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository. 
Connecting to an Amazon RDS database in a Lambda function using Rust.  

```
use aws_config::BehaviorVersion;
use aws_credential_types::provider::ProvideCredentials;
use aws_sigv4::{
    http_request::{sign, SignableBody, SignableRequest, SigningSettings},
    sign::v4,
};
use lambda_runtime::{run, service_fn, Error, LambdaEvent};
use serde_json::{json, Value};
use sqlx::postgres::PgConnectOptions;
use std::env;
use std::time::{Duration, SystemTime};

const RDS_CERTS: &[u8] = include_bytes!("global-bundle.pem");

async fn generate_rds_iam_token(
    db_hostname: &str,
    port: u16,
    db_username: &str,
) -> Result<String, Error> {
    let config = aws_config::load_defaults(BehaviorVersion::v2024_03_28()).await;

    let credentials = config
        .credentials_provider()
        .expect("no credentials provider found")
        .provide_credentials()
        .await
        .expect("unable to load credentials");
    let identity = credentials.into();
    let region = config.region().unwrap().to_string();

    let mut signing_settings = SigningSettings::default();
    signing_settings.expires_in = Some(Duration::from_secs(900));
    signing_settings.signature_location = aws_sigv4::http_request::SignatureLocation::QueryParams;

    let signing_params = v4::SigningParams::builder()
        .identity(&identity)
        .region(&region)
        .name("rds-db")
        .time(SystemTime::now())
        .settings(signing_settings)
        .build()?;

    let url = format!(
        "https://{db_hostname}:{port}/?Action=connect&DBUser={db_user}",
        db_hostname = db_hostname,
        port = port,
        db_user = db_username
    );

    let signable_request =
        SignableRequest::new("GET", &url, std::iter::empty(), SignableBody::Bytes(&[]))
            .expect("signable request");

    let (signing_instructions, _signature) =
        sign(signable_request, &signing_params.into())?.into_parts();

    let mut url = url::Url::parse(&url).unwrap();
    for (name, value) in signing_instructions.params() {
        url.query_pairs_mut().append_pair(name, &value);
    }

    let response = url.to_string().split_off("https://".len());

    Ok(response)
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    run(service_fn(handler)).await
}

async fn handler(_event: LambdaEvent<Value>) -> Result<Value, Error> {
    let db_host = env::var("DB_HOSTNAME").expect("DB_HOSTNAME must be set");
    let db_port = env::var("DB_PORT")
        .expect("DB_PORT must be set")
        .parse::<u16>()
        .expect("PORT must be a valid number");
    let db_name = env::var("DB_NAME").expect("DB_NAME must be set");
    let db_user_name = env::var("DB_USERNAME").expect("DB_USERNAME must be set");

    let token = generate_rds_iam_token(&db_host, db_port, &db_user_name).await?;

    let opts = PgConnectOptions::new()
        .host(&db_host)
        .port(db_port)
        .username(&db_user_name)
        .password(&token)
        .database(&db_name)
        .ssl_root_cert_from_pem(RDS_CERTS.to_vec())
        .ssl_mode(sqlx::postgres::PgSslMode::Require);

    let pool = sqlx::postgres::PgPoolOptions::new()
        .connect_with(opts)
        .await?;

    let result: i32 = sqlx::query_scalar("SELECT $1 + $2")
        .bind(3)
        .bind(2)
        .fetch_one(&pool)
        .await?;

    println!("Result: {:?}", result);

    Ok(json!({
        "statusCode": 200,
        "content-type": "text/plain",
        "body": format!("The selected sum is: {result}")
    }))
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from a Kinesis trigger
<a name="example_serverless_Kinesis_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving records from a Kinesis stream. The function retrieves the Kinesis payload, decodes from Base64, and logs the record contents.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming a Kinesis event with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using System.Text;
using Amazon.Lambda.Core;
using Amazon.Lambda.KinesisEvents;
using AWS.Lambda.Powertools.Logging;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace KinesisIntegrationSampleCode;

public class Function
{
    // Powertools Logger requires an environment variables against your function
    // POWERTOOLS_SERVICE_NAME
    [Logging(LogEvent = true)]
    public async Task FunctionHandler(KinesisEvent evnt, ILambdaContext context)
    {
        if (evnt.Records.Count == 0)
        {
            Logger.LogInformation("Empty Kinesis Event received");
            return;
        }

        foreach (var record in evnt.Records)
        {
            try
            {
                Logger.LogInformation($"Processed Event with EventId: {record.EventId}");
                string data = await GetRecordDataAsync(record.Kinesis, context);
                Logger.LogInformation($"Data: {data}");
                // TODO: Do interesting work based on the new data
            }
            catch (Exception ex)
            {
                Logger.LogError($"An error occurred {ex.Message}");
                throw;
            }
        }
        Logger.LogInformation($"Successfully processed {evnt.Records.Count} records.");
    }

    private async Task<string> GetRecordDataAsync(KinesisEvent.Record record, ILambdaContext context)
    {
        byte[] bytes = record.Data.ToArray();
        string data = Encoding.UTF8.GetString(bytes);
        await Task.CompletedTask; //Placeholder for actual async work
        return data;
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming a Kinesis event with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"log"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(ctx context.Context, kinesisEvent events.KinesisEvent) error {
	if len(kinesisEvent.Records) == 0 {
		log.Printf("empty Kinesis event received")
		return nil
	}

	for _, record := range kinesisEvent.Records {
		log.Printf("processed Kinesis event with EventId: %v", record.EventID)
		recordDataBytes := record.Kinesis.Data
		recordDataText := string(recordDataBytes)
		log.Printf("record data: %v", recordDataText)
		// TODO: Do interesting work based on the new data
	}
	log.Printf("successfully processed %v records", len(kinesisEvent.Records))
	return nil
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming a Kinesis event with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package example;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.KinesisEvent;

public class Handler implements RequestHandler<KinesisEvent, Void> {
    @Override
    public Void handleRequest(final KinesisEvent event, final Context context) {
        LambdaLogger logger = context.getLogger();
        if (event.getRecords().isEmpty()) {
            logger.log("Empty Kinesis Event received");
            return null;
        }
        for (KinesisEvent.KinesisEventRecord record : event.getRecords()) {
            try {
                logger.log("Processed Event with EventId: "+record.getEventID());
                String data = new String(record.getKinesis().getData().array());
                logger.log("Data:"+ data);
                // TODO: Do interesting work based on the new data
            }
            catch (Exception ex) {
                logger.log("An error occurred:"+ex.getMessage());
                throw ex;
            }
        }
        logger.log("Successfully processed:"+event.getRecords().size()+" records");
        return null;
    }

}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/blob/main/integration-kinesis-to-lambda) repository. 
Consuming a Kinesis event with Lambda using JavaScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
exports.handler = async (event, context) => {
  for (const record of event.Records) {
    try {
      console.log(`Processed Kinesis Event - EventID: ${record.eventID}`);
      const recordData = await getRecordDataAsync(record.kinesis);
      console.log(`Record Data: ${recordData}`);
      // TODO: Do interesting work based on the new data
    } catch (err) {
      console.error(`An error occurred ${err}`);
      throw err;
    }
  }
  console.log(`Successfully processed ${event.Records.length} records.`);
};

async function getRecordDataAsync(payload) {
  var data = Buffer.from(payload.data, "base64").toString("utf-8");
  await Promise.resolve(1); //Placeholder for actual async work
  return data;
}
```
Consuming a Kinesis event with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import {
  KinesisStreamEvent,
  Context,
  KinesisStreamHandler,
  KinesisStreamRecordPayload,
} from "aws-lambda";
import { Buffer } from "buffer";
import { Logger } from "@aws-lambda-powertools/logger";

const logger = new Logger({
  logLevel: "INFO",
  serviceName: "kinesis-stream-handler-sample",
});

export const functionHandler: KinesisStreamHandler = async (
  event: KinesisStreamEvent,
  context: Context
): Promise<void> => {
  for (const record of event.Records) {
    try {
      logger.info(`Processed Kinesis Event - EventID: ${record.eventID}`);
      const recordData = await getRecordDataAsync(record.kinesis);
      logger.info(`Record Data: ${recordData}`);
      // TODO: Do interesting work based on the new data
    } catch (err) {
      logger.error(`An error occurred ${err}`);
      throw err;
    }
    logger.info(`Successfully processed ${event.Records.length} records.`);
  }
};

async function getRecordDataAsync(
  payload: KinesisStreamRecordPayload
): Promise<string> {
  var data = Buffer.from(payload.data, "base64").toString("utf-8");
  await Promise.resolve(1); //Placeholder for actual async work
  return data;
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming an Kinesis event with Lambda using PHP.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
<?php

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\Kinesis\KinesisEvent;
use Bref\Event\Kinesis\KinesisHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler extends KinesisHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handleKinesis(KinesisEvent $event, Context $context): void
    {
        $this->logger->info("Processing records");
        $records = $event->getRecords();
        foreach ($records as $record) {
            $data = $record->getData();
            $this->logger->info(json_encode($data));
            // TODO: Do interesting work based on the new data

            // Any exception thrown will be logged and the invocation will be marked as failed
        }
        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords records");
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming a Kinesis event with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
import base64
def lambda_handler(event, context):

    for record in event['Records']:
        try:
            print(f"Processed Kinesis Event - EventID: {record['eventID']}")
            record_data = base64.b64decode(record['kinesis']['data']).decode('utf-8')
            print(f"Record Data: {record_data}")
            # TODO: Do interesting work based on the new data
        except Exception as e:
            print(f"An error occurred {e}")
            raise e
    print(f"Successfully processed {len(event['Records'])} records.")
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming an Kinesis event with Lambda using Ruby.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'aws-sdk'

def lambda_handler(event:, context:)
  event['Records'].each do |record|
    begin
      puts "Processed Kinesis Event - EventID: #{record['eventID']}"
      record_data = get_record_data_async(record['kinesis'])
      puts "Record Data: #{record_data}"
      # TODO: Do interesting work based on the new data
    rescue => err
      $stderr.puts "An error occurred #{err}"
      raise err
    end
  end
  puts "Successfully processed #{event['Records'].length} records."
end

def get_record_data_async(payload)
  data = Base64.decode64(payload['data']).force_encoding('UTF-8')
  # Placeholder for actual async work
  # You can use Ruby's asynchronous programming tools like async/await or fibers here.
  return data
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository. 
Consuming an Kinesis event with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::event::kinesis::KinesisEvent;
use lambda_runtime::{run, service_fn, Error, LambdaEvent};

async fn function_handler(event: LambdaEvent<KinesisEvent>) -> Result<(), Error> {
    if event.payload.records.is_empty() {
        tracing::info!("No records found. Exiting.");
        return Ok(());
    }

    event.payload.records.iter().for_each(|record| {
        tracing::info!("EventId: {}",record.event_id.as_deref().unwrap_or_default());

        let record_data = std::str::from_utf8(&record.kinesis.data);

        match record_data {
            Ok(data) => {
                // log the record data
                tracing::info!("Data: {}", data);
            }
            Err(e) => {
                tracing::error!("Error: {}", e);
            }
        }
    });

    tracing::info!(
        "Successfully processed {} records",
        event.payload.records.len()
    );

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        // disable printing the name of the module in every log line.
        .with_target(false)
        // disabling time is handy because CloudWatch will add the ingestion time.
        .without_time()
        .init();

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from a DynamoDB trigger
<a name="example_serverless_DynamoDB_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving records from a DynamoDB stream. The function retrieves the DynamoDB payload and logs the record contents.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using System.Text.Json;
using System.Text;
using Amazon.Lambda.Core;
using Amazon.Lambda.DynamoDBEvents;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace AWSLambda_DDB;

public class Function
{
    public void FunctionHandler(DynamoDBEvent dynamoEvent, ILambdaContext context)
    {
        context.Logger.LogInformation($"Beginning to process {dynamoEvent.Records.Count} records...");

        foreach (var record in dynamoEvent.Records)
        {
            context.Logger.LogInformation($"Event ID: {record.EventID}");
            context.Logger.LogInformation($"Event Name: {record.EventName}");

            context.Logger.LogInformation(JsonSerializer.Serialize(record));
        }

        context.Logger.LogInformation("Stream processing complete.");
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-lambda-go/events"
	"fmt"
)

func HandleRequest(ctx context.Context, event events.DynamoDBEvent) (*string, error) {
	if len(event.Records) == 0 {
		return nil, fmt.Errorf("received empty event")
	}

	for _, record := range event.Records {
	 	LogDynamoDBRecord(record)
	}

	message := fmt.Sprintf("Records processed: %d", len(event.Records))
	return &message, nil
}

func main() {
	lambda.Start(HandleRequest)
}

func LogDynamoDBRecord(record events.DynamoDBEventRecord){
	fmt.Println(record.EventID)
	fmt.Println(record.EventName)
	fmt.Printf("%+v\n", record.Change)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using Java.  

```
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.DynamodbEvent;
import com.amazonaws.services.lambda.runtime.events.DynamodbEvent.DynamodbStreamRecord;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class example implements RequestHandler<DynamodbEvent, Void> {

    private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();

    @Override
    public Void handleRequest(DynamodbEvent event, Context context) {
        System.out.println(GSON.toJson(event));
        event.getRecords().forEach(this::logDynamoDBRecord);
        return null;
    }

    private void logDynamoDBRecord(DynamodbStreamRecord record) {
        System.out.println(record.getEventID());
        System.out.println(record.getEventName());
        System.out.println("DynamoDB Record: " + GSON.toJson(record.getDynamodb()));
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using JavaScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
exports.handler = async (event, context) => {
    console.log(JSON.stringify(event, null, 2));
    event.Records.forEach(record => {
        logDynamoDBRecord(record);
    });
};

const logDynamoDBRecord = (record) => {
    console.log(record.eventID);
    console.log(record.eventName);
    console.log(`DynamoDB Record: ${JSON.stringify(record.dynamodb)}`);
};
```
Consuming a DynamoDB event with Lambda using TypeScript.  

```
export const handler = async (event, context) => {
    console.log(JSON.stringify(event, null, 2));
    event.Records.forEach(record => {
        logDynamoDBRecord(record);
    });
}
const logDynamoDBRecord = (record) => {
    console.log(record.eventID);
    console.log(record.eventName);
    console.log(`DynamoDB Record: ${JSON.stringify(record.dynamodb)}`);
};
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using PHP.  

```
<?php

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\DynamoDb\DynamoDbEvent;
use Bref\Event\DynamoDb\DynamoDbHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler extends DynamoDbHandler
{
    private StderrLogger $logger;

    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handleDynamoDb(DynamoDbEvent $event, Context $context): void
    {
        $this->logger->info("Processing DynamoDb table items");
        $records = $event->getRecords();

        foreach ($records as $record) {
            $eventName = $record->getEventName();
            $keys = $record->getKeys();
            $old = $record->getOldImage();
            $new = $record->getNewImage();
            
            $this->logger->info("Event Name:".$eventName."\n");
            $this->logger->info("Keys:". json_encode($keys)."\n");
            $this->logger->info("Old Image:". json_encode($old)."\n");
            $this->logger->info("New Image:". json_encode($new));
            
            // TODO: Do interesting work based on the new data

            // Any exception thrown will be logged and the invocation will be marked as failed
        }

        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords items");
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using Python.  

```
import json

def lambda_handler(event, context):
    print(json.dumps(event, indent=2))

    for record in event['Records']:
        log_dynamodb_record(record)

def log_dynamodb_record(record):
    print(record['eventID'])
    print(record['eventName'])
    print(f"DynamoDB Record: {json.dumps(record['dynamodb'])}")
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using Ruby.  

```
def lambda_handler(event:, context:)
    return 'received empty event' if event['Records'].empty?
  
    event['Records'].each do |record|
      log_dynamodb_record(record)
    end
  
    "Records processed: #{event['Records'].length}"
  end
  
  def log_dynamodb_record(record)
    puts record['eventID']
    puts record['eventName']
    puts "DynamoDB Record: #{JSON.generate(record['dynamodb'])}"
  end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository. 
Consuming a DynamoDB event with Lambda using Rust.  

```
use lambda_runtime::{service_fn, tracing, Error, LambdaEvent};
use aws_lambda_events::{
    event::dynamodb::{Event, EventRecord},
   };


// Built with the following dependencies:
//lambda_runtime = "0.11.1"
//serde_json = "1.0"
//tokio = { version = "1", features = ["macros"] }
//tracing = { version = "0.1", features = ["log"] }
//tracing-subscriber = { version = "0.3", default-features = false, features = ["fmt"] }
//aws_lambda_events = "0.15.0"

async fn function_handler(event: LambdaEvent<Event>) ->Result<(), Error> {
    
    let records = &event.payload.records;
    tracing::info!("event payload: {:?}",records);
    if records.is_empty() {
        tracing::info!("No records found. Exiting.");
        return Ok(());
    }

    for record in records{
        log_dynamo_dbrecord(record);
    }

    tracing::info!("Dynamo db records processed");

    // Prepare the response
    Ok(())

}

fn log_dynamo_dbrecord(record: &EventRecord)-> Result<(), Error>{
    tracing::info!("EventId: {}", record.event_id);
    tracing::info!("EventName: {}", record.event_name);
    tracing::info!("DynamoDB Record: {:?}", record.change );
    Ok(())

}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
    .with_max_level(tracing::Level::INFO)
    .with_target(false)
    .without_time()
    .init();

    let func = service_fn(function_handler);
    lambda_runtime::run(func).await?;
    Ok(())
    
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from a Amazon DocumentDB trigger
<a name="example_serverless_DocumentDB_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving records from a DocumentDB change stream. The function retrieves the DocumentDB payload and logs the record contents.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using .NET.  

```
using Amazon.Lambda.Core;
using System.Text.Json;
using System;
using System.Collections.Generic;
using System.Text.Json.Serialization;
//Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace LambdaDocDb;

public class Function
{
    
     /// <summary>
    /// Lambda function entry point to process Amazon DocumentDB events.
    /// </summary>
    /// <param name="event">The Amazon DocumentDB event.</param>
    /// <param name="context">The Lambda context object.</param>
    /// <returns>A string to indicate successful processing.</returns>
    public string FunctionHandler(Event evnt, ILambdaContext context)
    {
        
        foreach (var record in evnt.Events)
        {
            ProcessDocumentDBEvent(record, context);
        }

        return "OK";
    }

     private void ProcessDocumentDBEvent(DocumentDBEventRecord record, ILambdaContext context)
    {
        
        var eventData = record.Event;
        var operationType = eventData.OperationType;
        var databaseName = eventData.Ns.Db;
        var collectionName = eventData.Ns.Coll;
        var fullDocument = JsonSerializer.Serialize(eventData.FullDocument, new JsonSerializerOptions { WriteIndented = true });

        context.Logger.LogLine($"Operation type: {operationType}");
        context.Logger.LogLine($"Database: {databaseName}");
        context.Logger.LogLine($"Collection: {collectionName}");
        context.Logger.LogLine($"Full document:\n{fullDocument}");
    }



    public class Event
    {
        [JsonPropertyName("eventSourceArn")]
        public string EventSourceArn { get; set; }

        [JsonPropertyName("events")]
        public List<DocumentDBEventRecord> Events { get; set; }

        [JsonPropertyName("eventSource")]
        public string EventSource { get; set; }
    }

    public class DocumentDBEventRecord
    {
        [JsonPropertyName("event")]
        public EventData Event { get; set; }
    }

    public class EventData
    {
        [JsonPropertyName("_id")]
        public IdData Id { get; set; }

        [JsonPropertyName("clusterTime")]
        public ClusterTime ClusterTime { get; set; }

        [JsonPropertyName("documentKey")]
        public DocumentKey DocumentKey { get; set; }

        [JsonPropertyName("fullDocument")]
        public Dictionary<string, object> FullDocument { get; set; }

        [JsonPropertyName("ns")]
        public Namespace Ns { get; set; }

        [JsonPropertyName("operationType")]
        public string OperationType { get; set; }
    }

    public class IdData
    {
        [JsonPropertyName("_data")]
        public string Data { get; set; }
    }

    public class ClusterTime
    {
        [JsonPropertyName("$timestamp")]
        public Timestamp Timestamp { get; set; }
    }

    public class Timestamp
    {
        [JsonPropertyName("t")]
        public long T { get; set; }

        [JsonPropertyName("i")]
        public int I { get; set; }
    }

    public class DocumentKey
    {
        [JsonPropertyName("_id")]
        public Id Id { get; set; }
    }

    public class Id
    {
        [JsonPropertyName("$oid")]
        public string Oid { get; set; }
    }

    public class Namespace
    {
        [JsonPropertyName("db")]
        public string Db { get; set; }

        [JsonPropertyName("coll")]
        public string Coll { get; set; }
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using Go.  

```
package main

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/aws/aws-lambda-go/lambda"
)

type Event struct {
	Events []Record `json:"events"`
}

type Record struct {
	Event struct {
		OperationType string `json:"operationType"`
		NS            struct {
			DB   string `json:"db"`
			Coll string `json:"coll"`
		} `json:"ns"`
		FullDocument interface{} `json:"fullDocument"`
	} `json:"event"`
}

func main() {
	lambda.Start(handler)
}

func handler(ctx context.Context, event Event) (string, error) {
	fmt.Println("Loading function")
	for _, record := range event.Events {
		logDocumentDBEvent(record)
	}

	return "OK", nil
}

func logDocumentDBEvent(record Record) {
	fmt.Printf("Operation type: %s\n", record.Event.OperationType)
	fmt.Printf("db: %s\n", record.Event.NS.DB)
	fmt.Printf("collection: %s\n", record.Event.NS.Coll)
	docBytes, _ := json.MarshalIndent(record.Event.FullDocument, "", "  ")
	fmt.Printf("Full document: %s\n", string(docBytes))
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using Java.  

```
import java.util.List;
import java.util.Map;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;

public class Example implements RequestHandler<Map<String, Object>, String> {

    @SuppressWarnings("unchecked")
    @Override
    public String handleRequest(Map<String, Object> event, Context context) {
        List<Map<String, Object>> events = (List<Map<String, Object>>) event.get("events");
        for (Map<String, Object> record : events) {
            Map<String, Object> eventData = (Map<String, Object>) record.get("event");
            processEventData(eventData);
        }

        return "OK";
    }

    @SuppressWarnings("unchecked")
    private void processEventData(Map<String, Object> eventData) {
        String operationType = (String) eventData.get("operationType");
        System.out.println("operationType: %s".formatted(operationType));

        Map<String, Object> ns = (Map<String, Object>) eventData.get("ns");

        String db = (String) ns.get("db");
        System.out.println("db: %s".formatted(db));
        String coll = (String) ns.get("coll");
        System.out.println("coll: %s".formatted(coll));

        Map<String, Object> fullDocument = (Map<String, Object>) eventData.get("fullDocument");
        System.out.println("fullDocument: %s".formatted(fullDocument));
    }

}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using JavaScript.  

```
console.log('Loading function');
exports.handler = async (event, context) => {
    event.events.forEach(record => {
        logDocumentDBEvent(record);
    });
    return 'OK';
};

const logDocumentDBEvent = (record) => {
    console.log('Operation type: ' + record.event.operationType);
    console.log('db: ' + record.event.ns.db);
    console.log('collection: ' + record.event.ns.coll);
    console.log('Full document:', JSON.stringify(record.event.fullDocument, null, 2));
};
```
Consuming a Amazon DocumentDB event with Lambda using TypeScript  

```
import { DocumentDBEventRecord, DocumentDBEventSubscriptionContext } from 'aws-lambda';

console.log('Loading function');

export const handler = async (
  event: DocumentDBEventSubscriptionContext,
  context: any
): Promise<string> => {
  event.events.forEach((record: DocumentDBEventRecord) => {
    logDocumentDBEvent(record);
  });
  return 'OK';
};

const logDocumentDBEvent = (record: DocumentDBEventRecord): void => {
  console.log('Operation type: ' + record.event.operationType);
  console.log('db: ' + record.event.ns.db);
  console.log('collection: ' + record.event.ns.coll);
  console.log('Full document:', JSON.stringify(record.event.fullDocument, null, 2));
};
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using PHP.  

```
<?php

require __DIR__.'/vendor/autoload.php';

use Bref\Context\Context;
use Bref\Event\Handler;

class DocumentDBEventHandler implements Handler
{
    public function handle($event, Context $context): string
    {

        $events = $event['events'] ?? [];
        foreach ($events as $record) {
            $this->logDocumentDBEvent($record['event']);
        }
        return 'OK';
    }

    private function logDocumentDBEvent($event): void
    {
        // Extract information from the event record

        $operationType = $event['operationType'] ?? 'Unknown';
        $db = $event['ns']['db'] ?? 'Unknown';
        $collection = $event['ns']['coll'] ?? 'Unknown';
        $fullDocument = $event['fullDocument'] ?? [];

        // Log the event details

        echo "Operation type: $operationType\n";
        echo "Database: $db\n";
        echo "Collection: $collection\n";
        echo "Full document: " . json_encode($fullDocument, JSON_PRETTY_PRINT) . "\n";
    }
}
return new DocumentDBEventHandler();
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using Python.  

```
import json

def lambda_handler(event, context):
    for record in event.get('events', []):
        log_document_db_event(record)
    return 'OK'

def log_document_db_event(record):
    event_data = record.get('event', {})
    operation_type = event_data.get('operationType', 'Unknown')
    db = event_data.get('ns', {}).get('db', 'Unknown')
    collection = event_data.get('ns', {}).get('coll', 'Unknown')
    full_document = event_data.get('fullDocument', {})

    print(f"Operation type: {operation_type}")
    print(f"db: {db}")
    print(f"collection: {collection}")
    print("Full document:", json.dumps(full_document, indent=2))
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using Ruby.  

```
require 'json'

def lambda_handler(event:, context:)
  event['events'].each do |record|
    log_document_db_event(record)
  end
  'OK'
end

def log_document_db_event(record)
  event_data = record['event'] || {}
  operation_type = event_data['operationType'] || 'Unknown'
  db = event_data.dig('ns', 'db') || 'Unknown'
  collection = event_data.dig('ns', 'coll') || 'Unknown'
  full_document = event_data['fullDocument'] || {}

  puts "Operation type: #{operation_type}"
  puts "db: #{db}"
  puts "collection: #{collection}"
  puts "Full document: #{JSON.pretty_generate(full_document)}"
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository. 
Consuming a Amazon DocumentDB event with Lambda using Rust.  

```
use lambda_runtime::{service_fn, tracing, Error, LambdaEvent};
use aws_lambda_events::{
    event::documentdb::{DocumentDbEvent, DocumentDbInnerEvent},
   };


// Built with the following dependencies:
//lambda_runtime = "0.11.1"
//serde_json = "1.0"
//tokio = { version = "1", features = ["macros"] }
//tracing = { version = "0.1", features = ["log"] }
//tracing-subscriber = { version = "0.3", default-features = false, features = ["fmt"] }
//aws_lambda_events = "0.15.0"

async fn function_handler(event: LambdaEvent<DocumentDbEvent>) ->Result<(), Error> {
    
    tracing::info!("Event Source ARN: {:?}", event.payload.event_source_arn);
    tracing::info!("Event Source: {:?}", event.payload.event_source);
  
    let records = &event.payload.events;
   
    if records.is_empty() {
        tracing::info!("No records found. Exiting.");
        return Ok(());
    }

    for record in records{
        log_document_db_event(record);
    }

    tracing::info!("Document db records processed");

    // Prepare the response
    Ok(())

}

fn log_document_db_event(record: &DocumentDbInnerEvent)-> Result<(), Error>{
    tracing::info!("Change Event: {:?}", record.event);
    
    Ok(())

}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
    .with_max_level(tracing::Level::INFO)
    .with_target(false)
    .without_time()
    .init();

    let func = service_fn(function_handler);
    lambda_runtime::run(func).await?;
    Ok(())
    
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from an Amazon MSK trigger
<a name="example_serverless_MSK_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving records from an Amazon MSK cluster. The function retrieves the MSK payload and logs the record contents.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using .NET.  

```
using System.Text;
using Amazon.Lambda.Core;
using Amazon.Lambda.KafkaEvents;


// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace MSKLambda;

public class Function
{
    
    
    /// <param name="input">The event for the Lambda function handler to process.</param>
    /// <param name="context">The ILambdaContext that provides methods for logging and describing the Lambda environment.</param>
    /// <returns></returns>
    public void FunctionHandler(KafkaEvent evnt, ILambdaContext context)
    {

        foreach (var record in evnt.Records)
        {
            Console.WriteLine("Key:" + record.Key); 
            foreach (var eventRecord in record.Value)
            {
                var valueBytes = eventRecord.Value.ToArray();    
                var valueText = Encoding.UTF8.GetString(valueBytes);
                
                Console.WriteLine("Message:" + valueText);
            }
        }
    }
    

}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using Go.  

```
package main

import (
	"encoding/base64"
	"fmt"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(event events.KafkaEvent) {
	for key, records := range event.Records {
		fmt.Println("Key:", key)

		for _, record := range records {
			fmt.Println("Record:", record)

			decodedValue, _ := base64.StdEncoding.DecodeString(record.Value)
			message := string(decodedValue)
			fmt.Println("Message:", message)
		}
	}
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using Java.  

```
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.KafkaEvent;
import com.amazonaws.services.lambda.runtime.events.KafkaEvent.KafkaEventRecord;

import java.util.Base64;
import java.util.Map;

public class Example implements RequestHandler<KafkaEvent, Void> {

    @Override
    public Void handleRequest(KafkaEvent event, Context context) {
        for (Map.Entry<String, java.util.List<KafkaEventRecord>> entry : event.getRecords().entrySet()) {
            String key = entry.getKey();
            System.out.println("Key: " + key);

            for (KafkaEventRecord record : entry.getValue()) {
                System.out.println("Record: " + record);

                byte[] value = Base64.getDecoder().decode(record.getValue());
                String message = new String(value);
                System.out.println("Message: " + message);
            }
        }

        return null;
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using JavaScript.  

```
exports.handler = async (event) => {
    // Iterate through keys
    for (let key in event.records) {
      console.log('Key: ', key)
      // Iterate through records
      event.records[key].map((record) => {
        console.log('Record: ', record)
        // Decode base64
        const msg = Buffer.from(record.value, 'base64').toString()
        console.log('Message:', msg)
      }) 
    }
}
```
Consuming an Amazon MSK event with Lambda using TypeScript.  

```
import { MSKEvent, Context } from "aws-lambda";
import { Buffer } from "buffer";
import { Logger } from "@aws-lambda-powertools/logger";

const logger = new Logger({
  logLevel: "INFO",
  serviceName: "msk-handler-sample",
});

export const handler = async (
  event: MSKEvent,
  context: Context
): Promise<void> => {
  for (const [topic, topicRecords] of Object.entries(event.records)) {
    logger.info(`Processing key: ${topic}`);

    // Process each record in the partition
    for (const record of topicRecords) {
      try {
        // Decode the message value from base64
        const decodedMessage = Buffer.from(record.value, 'base64').toString();

        logger.info({
          message: decodedMessage
        });
      }
      catch (error) {
        logger.error('Error processing event', { error });
        throw error;
      }
    };
  }
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using PHP.  

```
<?php
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

// using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\Kafka\KafkaEvent;
use Bref\Event\Handler as StdHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler implements StdHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handle(mixed $event, Context $context): void
    {
        $kafkaEvent = new KafkaEvent($event);
        $this->logger->info("Processing records");
        $records = $kafkaEvent->getRecords();

        foreach ($records as $record) {
            try {
                $key = $record->getKey();
                $this->logger->info("Key: $key");

                $values = $record->getValue();
                $this->logger->info(json_encode($values));

                foreach ($values as $value) {
                    $this->logger->info("Value: $value");
                }
                
            } catch (Exception $e) {
                $this->logger->error($e->getMessage());
            }
        }
        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords records");
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using Python.  

```
import base64

def lambda_handler(event, context):
    # Iterate through keys
    for key in event['records']:
        print('Key:', key)
        # Iterate through records
        for record in event['records'][key]:
            print('Record:', record)
            # Decode base64
            msg = base64.b64decode(record['value']).decode('utf-8')
            print('Message:', msg)
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using Ruby.  

```
require 'base64'

def lambda_handler(event:, context:)
  # Iterate through keys
  event['records'].each do |key, records|
    puts "Key: #{key}"

    # Iterate through records
    records.each do |record|
      puts "Record: #{record}"

      # Decode base64
      msg = Base64.decode64(record['value'])
      puts "Message: #{msg}"
    end
  end
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository. 
Consuming an Amazon MSK event with Lambda using Rust.  

```
use aws_lambda_events::event::kafka::KafkaEvent;
use lambda_runtime::{run, service_fn, tracing, Error, LambdaEvent};
use base64::prelude::*;
use serde_json::{Value};
use tracing::{info};

/// Pre-Requisites:
/// 1. Install Cargo Lambda - see https://www.cargo-lambda.info/guide/getting-started.html
/// 2. Add packages tracing, tracing-subscriber, serde_json, base64
///
/// This is the main body for the function.
/// Write your code inside it.
/// There are some code example in the following URLs:
/// - https://github.com/awslabs/aws-lambda-rust-runtime/tree/main/examples
/// - https://github.com/aws-samples/serverless-rust-demo/

async fn function_handler(event: LambdaEvent<KafkaEvent>) -> Result<Value, Error> {

    let payload = event.payload.records;

    for (_name, records) in payload.iter() {

        for record in records {

         let record_text = record.value.as_ref().ok_or("Value is None")?;
         info!("Record: {}", &record_text);

         // perform Base64 decoding
         let record_bytes = BASE64_STANDARD.decode(record_text)?;
         let message = std::str::from_utf8(&record_bytes)?;
         
         info!("Message: {}", message);
        }

    }

    Ok(().into())
}

#[tokio::main]
async fn main() -> Result<(), Error> {

    // required to enable CloudWatch error logging by the runtime
    tracing::init_default_subscriber();
    info!("Setup CW subscriber!");

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from an Amazon S3 trigger
<a name="example_serverless_S3_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by uploading an object to an S3 bucket. The function retrieves the S3 bucket name and object key from the event parameter and calls the Amazon S3 API to retrieve and log the content type of the object.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using System.Threading.Tasks;
using Amazon.Lambda.Core;
using Amazon.S3;
using System;
using Amazon.Lambda.S3Events;
using System.Web;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace S3Integration
{
    public class Function
    {
        private static AmazonS3Client _s3Client;
        public Function() : this(null)
        {
        }

        internal Function(AmazonS3Client s3Client)
        {
            _s3Client = s3Client ?? new AmazonS3Client();
        }

        public async Task<string> Handler(S3Event evt, ILambdaContext context)
        {
            try
            {
                if (evt.Records.Count <= 0)
                {
                    context.Logger.LogLine("Empty S3 Event received");
                    return string.Empty;
                }

                var bucket = evt.Records[0].S3.Bucket.Name;
                var key = HttpUtility.UrlDecode(evt.Records[0].S3.Object.Key);

                context.Logger.LogLine($"Request is for {bucket} and {key}");

                var objectResult = await _s3Client.GetObjectAsync(bucket, key);

                context.Logger.LogLine($"Returning {objectResult.Key}");

                return objectResult.Key;
            }
            catch (Exception e)
            {
                context.Logger.LogLine($"Error processing request - {e.Message}");

                return string.Empty;
            }
        }
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"log"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/s3"
)

func handler(ctx context.Context, s3Event events.S3Event) error {
	sdkConfig, err := config.LoadDefaultConfig(ctx)
	if err != nil {
		log.Printf("failed to load default config: %s", err)
		return err
	}
	s3Client := s3.NewFromConfig(sdkConfig)

	for _, record := range s3Event.Records {
		bucket := record.S3.Bucket.Name
		key := record.S3.Object.URLDecodedKey
		headOutput, err := s3Client.HeadObject(ctx, &s3.HeadObjectInput{
			Bucket: &bucket,
			Key:    &key,
		})
		if err != nil {
			log.Printf("error getting head of object %s/%s: %s", bucket, key, err)
			return err
		}
		log.Printf("successfully retrieved %s/%s of type %s", bucket, key, *headOutput.ContentType)
	}

	return nil
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package example;

import software.amazon.awssdk.services.s3.model.HeadObjectRequest;
import software.amazon.awssdk.services.s3.model.HeadObjectResponse;
import software.amazon.awssdk.services.s3.S3Client;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.S3Event;
import com.amazonaws.services.lambda.runtime.events.models.s3.S3EventNotification.S3EventNotificationRecord;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Handler implements RequestHandler<S3Event, String> {
    private static final Logger logger = LoggerFactory.getLogger(Handler.class);
    @Override
    public String handleRequest(S3Event s3event, Context context) {
        try {
          S3EventNotificationRecord record = s3event.getRecords().get(0);
          String srcBucket = record.getS3().getBucket().getName();
          String srcKey = record.getS3().getObject().getUrlDecodedKey();

          S3Client s3Client = S3Client.builder().build();
          HeadObjectResponse headObject = getHeadObject(s3Client, srcBucket, srcKey);

          logger.info("Successfully retrieved " + srcBucket + "/" + srcKey + " of type " + headObject.contentType());

          return "Ok";
        } catch (Exception e) {
          throw new RuntimeException(e);
        }
    }

    private HeadObjectResponse getHeadObject(S3Client s3Client, String bucket, String key) {
        HeadObjectRequest headObjectRequest = HeadObjectRequest.builder()
                .bucket(bucket)
                .key(key)
                .build();
        return s3Client.headObject(headObjectRequest);
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using JavaScript.  

```
import { S3Client, HeadObjectCommand } from "@aws-sdk/client-s3";

const client = new S3Client();

export const handler = async (event, context) => {

    // Get the object from the event and show its content type
    const bucket = event.Records[0].s3.bucket.name;
    const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));

    try {
        const { ContentType } = await client.send(new HeadObjectCommand({
            Bucket: bucket,
            Key: key,
        }));

        console.log('CONTENT TYPE:', ContentType);
        return ContentType;

    } catch (err) {
        console.log(err);
        const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`;
        console.log(message);
        throw new Error(message);
    }
};
```
Consuming an S3 event with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import { S3Event } from 'aws-lambda';
import { S3Client, HeadObjectCommand } from '@aws-sdk/client-s3';

const s3 = new S3Client({ region: process.env.AWS_REGION });

export const handler = async (event: S3Event): Promise<string | undefined> => {
  // Get the object from the event and show its content type
  const bucket = event.Records[0].s3.bucket.name;
  const key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, ' '));
  const params = {
    Bucket: bucket,
    Key: key,
  };
  try {
    const { ContentType } = await s3.send(new HeadObjectCommand(params));
    console.log('CONTENT TYPE:', ContentType);
    return ContentType;
  } catch (err) {
    console.log(err);
    const message = `Error getting object ${key} from bucket ${bucket}. Make sure they exist and your bucket is in the same region as this function.`;
    console.log(message);
    throw new Error(message);
  }
};
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using PHP.  

```
<?php

use Bref\Context\Context;
use Bref\Event\S3\S3Event;
use Bref\Event\S3\S3Handler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';


class Handler extends S3Handler 
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }
    
    public function handleS3(S3Event $event, Context $context) : void
    {
        $this->logger->info("Processing S3 records");

        // Get the object from the event and show its content type
        $records = $event->getRecords();
        
        foreach ($records as $record) 
        {
            $bucket = $record->getBucket()->getName();
            $key = urldecode($record->getObject()->getKey());

            try {
                $fileSize = urldecode($record->getObject()->getSize());
                echo "File Size: " . $fileSize . "\n";
                // TODO: Implement your custom processing logic here
            } catch (Exception $e) {
                echo $e->getMessage() . "\n";
                echo 'Error getting object ' . $key . ' from bucket ' . $bucket . '. Make sure they exist and your bucket is in the same region as this function.' . "\n";
                throw $e;
            }
        }
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
import json
import urllib.parse
import boto3

print('Loading function')

s3 = boto3.client('s3')


def lambda_handler(event, context):
    #print("Received event: " + json.dumps(event, indent=2))

    # Get the object from the event and show its content type
    bucket = event['Records'][0]['s3']['bucket']['name']
    key = urllib.parse.unquote_plus(event['Records'][0]['s3']['object']['key'], encoding='utf-8')
    try:
        response = s3.get_object(Bucket=bucket, Key=key)
        print("CONTENT TYPE: " + response['ContentType'])
        return response['ContentType']
    except Exception as e:
        print(e)
        print('Error getting object {} from bucket {}. Make sure they exist and your bucket is in the same region as this function.'.format(key, bucket))
        raise e
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using Ruby.  

```
require 'json'
require 'uri'
require 'aws-sdk'

puts 'Loading function'

def lambda_handler(event:, context:)
  s3 = Aws::S3::Client.new(region: 'region') # Your AWS region
  # puts "Received event: #{JSON.dump(event)}"

  # Get the object from the event and show its content type
  bucket = event['Records'][0]['s3']['bucket']['name']
  key = URI.decode_www_form_component(event['Records'][0]['s3']['object']['key'], Encoding::UTF_8)
  begin
    response = s3.get_object(bucket: bucket, key: key)
    puts "CONTENT TYPE: #{response.content_type}"
    return response.content_type
  rescue StandardError => e
    puts e.message
    puts "Error getting object #{key} from bucket #{bucket}. Make sure they exist and your bucket is in the same region as this function."
    raise e
  end
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository. 
Consuming an S3 event with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::event::s3::S3Event;
use aws_sdk_s3::{Client};
use lambda_runtime::{run, service_fn, Error, LambdaEvent};


/// Main function
#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        .with_target(false)
        .without_time()
        .init();

    // Initialize the AWS SDK for Rust
    let config = aws_config::load_from_env().await;
    let s3_client = Client::new(&config);

    let res = run(service_fn(|request: LambdaEvent<S3Event>| {
        function_handler(&s3_client, request)
    })).await;

    res
}

async fn function_handler(
    s3_client: &Client,
    evt: LambdaEvent<S3Event>
) -> Result<(), Error> {
    tracing::info!(records = ?evt.payload.records.len(), "Received request from SQS");

    if evt.payload.records.len() == 0 {
        tracing::info!("Empty S3 event received");
    }

    let bucket = evt.payload.records[0].s3.bucket.name.as_ref().expect("Bucket name to exist");
    let key = evt.payload.records[0].s3.object.key.as_ref().expect("Object key to exist");

    tracing::info!("Request is for {} and object {}", bucket, key);

    let s3_get_object_result = s3_client
        .get_object()
        .bucket(bucket)
        .key(key)
        .send()
        .await;

    match s3_get_object_result {
        Ok(_) => tracing::info!("S3 Get Object success, the s3GetObjectResult contains a 'body' property of type ByteStream"),
        Err(_) => tracing::info!("Failure with S3 Get Object request")
    }

    Ok(())
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from an Amazon SNS trigger
<a name="example_serverless_SNS_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving messages from an SNS topic. The function retrieves the messages from the event parameter and logs the content of each message.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using Amazon.Lambda.Core;
using Amazon.Lambda.SNSEvents;


// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace SnsIntegration;

public class Function
{
    public async Task FunctionHandler(SNSEvent evnt, ILambdaContext context)
    {
        foreach (var record in evnt.Records)
        {
            await ProcessRecordAsync(record, context);
        }
        context.Logger.LogInformation("done");
    }

    private async Task ProcessRecordAsync(SNSEvent.SNSRecord record, ILambdaContext context)
    {
        try
        {
            context.Logger.LogInformation($"Processed record {record.Sns.Message}");

            // TODO: Do interesting work based on the new message
            await Task.CompletedTask;
        }
        catch (Exception e)
        {
            //You can use Dead Letter Queue to handle failures. By configuring a Lambda DLQ.
            context.Logger.LogError($"An error occurred");
            throw;
        }
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"fmt"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(ctx context.Context, snsEvent events.SNSEvent) {
	for _, record := range snsEvent.Records {
		processMessage(record)
	}
	fmt.Println("done")
}

func processMessage(record events.SNSEventRecord) {
	message := record.SNS.Message
	fmt.Printf("Processed message: %s\n", message)
	// TODO: Process your record here
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package example;

import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.LambdaLogger;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.SNSEvent;
import com.amazonaws.services.lambda.runtime.events.SNSEvent.SNSRecord;


import java.util.Iterator;
import java.util.List;

public class SNSEventHandler implements RequestHandler<SNSEvent, Boolean> {
    LambdaLogger logger;

    @Override
    public Boolean handleRequest(SNSEvent event, Context context) {
        logger = context.getLogger();
        List<SNSRecord> records = event.getRecords();
        if (!records.isEmpty()) {
            Iterator<SNSRecord> recordsIter = records.iterator();
            while (recordsIter.hasNext()) {
                processRecord(recordsIter.next());
            }
        }
        return Boolean.TRUE;
    }

    public void processRecord(SNSRecord record) {
        try {
            String message = record.getSNS().getMessage();
            logger.log("message: " + message);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/blob/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using JavaScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
exports.handler = async (event, context) => {
  for (const record of event.Records) {
    await processMessageAsync(record);
  }
  console.info("done");
};

async function processMessageAsync(record) {
  try {
    const message = JSON.stringify(record.Sns.Message);
    console.log(`Processed message ${message}`);
    await Promise.resolve(1); //Placeholder for actual async work
  } catch (err) {
    console.error("An error occurred");
    throw err;
  }
}
```
Consuming an SNS event with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import { SNSEvent, Context, SNSHandler, SNSEventRecord } from "aws-lambda";

export const functionHandler: SNSHandler = async (
  event: SNSEvent,
  context: Context
): Promise<void> => {
  for (const record of event.Records) {
    await processMessageAsync(record);
  }
  console.info("done");
};

async function processMessageAsync(record: SNSEventRecord): Promise<any> {
  try {
    const message: string = JSON.stringify(record.Sns.Message);
    console.log(`Processed message ${message}`);
    await Promise.resolve(1); //Placeholder for actual async work
  } catch (err) {
    console.error("An error occurred");
    throw err;
  }
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using PHP.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
<?php

/* 
Since native PHP support for AWS Lambda is not available, we are utilizing Bref's PHP functions runtime for AWS Lambda.
For more information on Bref's PHP runtime for Lambda, refer to: https://bref.sh/docs/runtimes/function

Another approach would be to create a custom runtime. 
A practical example can be found here: https://aws.amazon.com/blogs/apn/aws-lambda-custom-runtime-for-php-a-practical-example/
*/

// Additional composer packages may be required when using Bref or any other PHP functions runtime.
// require __DIR__ . '/vendor/autoload.php';

use Bref\Context\Context;
use Bref\Event\Sns\SnsEvent;
use Bref\Event\Sns\SnsHandler;

class Handler extends SnsHandler
{
    public function handleSns(SnsEvent $event, Context $context): void
    {
        foreach ($event->getRecords() as $record) {
            $message = $record->getMessage();

            // TODO: Implement your custom processing logic here
            // Any exception thrown will be logged and the invocation will be marked as failed

            echo "Processed Message: $message" . PHP_EOL;
        }
    }
}

return new Handler();
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event, context):
    for record in event['Records']:
        process_message(record)
    print("done")

def process_message(record):
    try:
        message = record['Sns']['Message']
        print(f"Processed message {message}")
        # TODO; Process your record here
        
    except Exception as e:
        print("An error occurred")
        raise e
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using Ruby.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event:, context:)
  event['Records'].map { |record| process_message(record) }
end

def process_message(record)
  message = record['Sns']['Message']
  puts("Processing message: #{message}")
rescue StandardError => e
  puts("Error processing message: #{e}")
  raise
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository. 
Consuming an SNS event with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::event::sns::SnsEvent;
use aws_lambda_events::sns::SnsRecord;
use lambda_runtime::{run, service_fn, Error, LambdaEvent};
use tracing::info;

// Built with the following dependencies:
//  aws_lambda_events = { version = "0.10.0", default-features = false, features = ["sns"] }
//  lambda_runtime = "0.8.1"
//  tokio = { version = "1", features = ["macros"] }
//  tracing = { version = "0.1", features = ["log"] }
//  tracing-subscriber = { version = "0.3", default-features = false, features = ["fmt"] }

async fn function_handler(event: LambdaEvent<SnsEvent>) -> Result<(), Error> {
    for event in event.payload.records {
        process_record(&event)?;
    }
    
    Ok(())
}

fn process_record(record: &SnsRecord) -> Result<(), Error> {
    info!("Processing SNS Message: {}", record.sns.message);

    // Implement your record handling code here.

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        .with_target(false)
        .without_time()
        .init();

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Invoke a Lambda function from an Amazon SQS trigger
<a name="example_serverless_SQS_Lambda_section"></a>

The following code examples show how to implement a Lambda function that receives an event triggered by receiving messages from an SQS queue. The function retrieves the messages from the event parameter and logs the content of each message.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using Amazon.Lambda.Core;
using Amazon.Lambda.SQSEvents;


// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace SqsIntegrationSampleCode
{
    public async Task FunctionHandler(SQSEvent evnt, ILambdaContext context)
    {
        foreach (var message in evnt.Records)
        {
            await ProcessMessageAsync(message, context);
        }

        context.Logger.LogInformation("done");
    }

    private async Task ProcessMessageAsync(SQSEvent.SQSMessage message, ILambdaContext context)
    {
        try
        {
            context.Logger.LogInformation($"Processed message {message.Body}");

            // TODO: Do interesting work based on the new message
            await Task.CompletedTask;
        }
        catch (Exception e)
        {
            //You can use Dead Letter Queue to handle failures. By configuring a Lambda DLQ.
            context.Logger.LogError($"An error occurred");
            throw;
        }

    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package integration_sqs_to_lambda

import (
	"fmt"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(event events.SQSEvent) error {
	for _, record := range event.Records {
		err := processMessage(record)
		if err != nil {
			return err
		}
	}
	fmt.Println("done")
	return nil
}

func processMessage(record events.SQSMessage) error {
	fmt.Printf("Processed message %s\n", record.Body)
	// TODO: Do interesting work based on the new message
	return nil
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.SQSEvent;
import com.amazonaws.services.lambda.runtime.events.SQSEvent.SQSMessage;

public class Function implements RequestHandler<SQSEvent, Void> {
    @Override
    public Void handleRequest(SQSEvent sqsEvent, Context context) {
        for (SQSMessage msg : sqsEvent.getRecords()) {
            processMessage(msg, context);
        }
        context.getLogger().log("done");
        return null;
    }

    private void processMessage(SQSMessage msg, Context context) {
        try {
            context.getLogger().log("Processed message " + msg.getBody());

            // TODO: Do interesting work based on the new message

        } catch (Exception e) {
            context.getLogger().log("An error occurred");
            throw e;
        }

    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/blob/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using JavaScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
exports.handler = async (event, context) => {
  for (const message of event.Records) {
    await processMessageAsync(message);
  }
  console.info("done");
};

async function processMessageAsync(message) {
  try {
    console.log(`Processed message ${message.body}`);
    // TODO: Do interesting work based on the new message
    await Promise.resolve(1); //Placeholder for actual async work
  } catch (err) {
    console.error("An error occurred");
    throw err;
  }
}
```
Consuming an SQS event with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import { SQSEvent, Context, SQSHandler, SQSRecord } from "aws-lambda";

export const functionHandler: SQSHandler = async (
  event: SQSEvent,
  context: Context
): Promise<void> => {
  for (const message of event.Records) {
    await processMessageAsync(message);
  }
  console.info("done");
};

async function processMessageAsync(message: SQSRecord): Promise<any> {
  try {
    console.log(`Processed message ${message.body}`);
    // TODO: Do interesting work based on the new message
    await Promise.resolve(1); //Placeholder for actual async work
  } catch (err) {
    console.error("An error occurred");
    throw err;
  }
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using PHP.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
<?php

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\InvalidLambdaEvent;
use Bref\Event\Sqs\SqsEvent;
use Bref\Event\Sqs\SqsHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler extends SqsHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws InvalidLambdaEvent
     */
    public function handleSqs(SqsEvent $event, Context $context): void
    {
        foreach ($event->getRecords() as $record) {
            $body = $record->getBody();
            // TODO: Do interesting work based on the new message
        }
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event, context):
    for message in event['Records']:
        process_message(message)
    print("done")

def process_message(message):
    try:
        print(f"Processed message {message['body']}")
        # TODO: Do interesting work based on the new message
    except Exception as err:
        print("An error occurred")
        raise err
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using Ruby.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event:, context:)
  event['Records'].each do |message|
    process_message(message)
  end
  puts "done"
end

def process_message(message)
  begin
    puts "Processed message #{message['body']}"
    # TODO: Do interesting work based on the new message
  rescue StandardError => err
    puts "An error occurred"
    raise err
  end
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository. 
Consuming an SQS event with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::event::sqs::SqsEvent;
use lambda_runtime::{run, service_fn, Error, LambdaEvent};

async fn function_handler(event: LambdaEvent<SqsEvent>) -> Result<(), Error> {
    event.payload.records.iter().for_each(|record| {
        // process the record
        tracing::info!("Message body: {}", record.body.as_deref().unwrap_or_default())
    });

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        // disable printing the name of the module in every log line.
        .with_target(false)
        // disabling time is handy because CloudWatch will add the ingestion time.
        .without_time()
        .init();

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Reporting batch item failures for Lambda functions with a Kinesis trigger
<a name="example_serverless_Kinesis_Lambda_batch_item_failures_section"></a>

The following code examples show how to implement partial batch response for Lambda functions that receive events from a Kinesis stream. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using System.Text;
using System.Text.Json.Serialization;
using Amazon.Lambda.Core;
using Amazon.Lambda.KinesisEvents;
using AWS.Lambda.Powertools.Logging;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace KinesisIntegration;

public class Function
{
    // Powertools Logger requires an environment variables against your function
    // POWERTOOLS_SERVICE_NAME
    [Logging(LogEvent = true)]
    public async Task<StreamsEventResponse> FunctionHandler(KinesisEvent evnt, ILambdaContext context)
    {
        if (evnt.Records.Count == 0)
        {
            Logger.LogInformation("Empty Kinesis Event received");
            return new StreamsEventResponse();
        }

        foreach (var record in evnt.Records)
        {
            try
            {
                Logger.LogInformation($"Processed Event with EventId: {record.EventId}");
                string data = await GetRecordDataAsync(record.Kinesis, context);
                Logger.LogInformation($"Data: {data}");
                // TODO: Do interesting work based on the new data
            }
            catch (Exception ex)
            {
                Logger.LogError($"An error occurred {ex.Message}");
                /* Since we are working with streams, we can return the failed item immediately.
                   Lambda will immediately begin to retry processing from this failed item onwards. */
                return new StreamsEventResponse
                {
                    BatchItemFailures = new List<StreamsEventResponse.BatchItemFailure>
                    {
                        new StreamsEventResponse.BatchItemFailure { ItemIdentifier = record.Kinesis.SequenceNumber }
                    }
                };
            }
        }
        Logger.LogInformation($"Successfully processed {evnt.Records.Count} records.");
        return new StreamsEventResponse();
    }

    private async Task<string> GetRecordDataAsync(KinesisEvent.Record record, ILambdaContext context)
    {
        byte[] bytes = record.Data.ToArray();
        string data = Encoding.UTF8.GetString(bytes);
        await Task.CompletedTask; //Placeholder for actual async work
        return data;
    }
}

public class StreamsEventResponse
{
    [JsonPropertyName("batchItemFailures")]
    public IList<BatchItemFailure> BatchItemFailures { get; set; }
    public class BatchItemFailure
    {
        [JsonPropertyName("itemIdentifier")]
        public string ItemIdentifier { get; set; }
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"fmt"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(ctx context.Context, kinesisEvent events.KinesisEvent) (map[string]interface{}, error) {
	batchItemFailures := []map[string]interface{}{}

	for _, record := range kinesisEvent.Records {
		curRecordSequenceNumber := ""

		// Process your record
		if /* Your record processing condition here */ {
			curRecordSequenceNumber = record.Kinesis.SequenceNumber
		}

		// Add a condition to check if the record processing failed
		if curRecordSequenceNumber != "" {
			batchItemFailures = append(batchItemFailures, map[string]interface{}{"itemIdentifier": curRecordSequenceNumber})
		}
	}

	kinesisBatchResponse := map[string]interface{}{
		"batchItemFailures": batchItemFailures,
	}
	return kinesisBatchResponse, nil
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.KinesisEvent;
import com.amazonaws.services.lambda.runtime.events.StreamsEventResponse;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public class ProcessKinesisRecords implements RequestHandler<KinesisEvent, StreamsEventResponse> {

    @Override
    public StreamsEventResponse handleRequest(KinesisEvent input, Context context) {

        List<StreamsEventResponse.BatchItemFailure> batchItemFailures = new ArrayList<>();
        String curRecordSequenceNumber = "";

        for (KinesisEvent.KinesisEventRecord kinesisEventRecord : input.getRecords()) {
            try {
                //Process your record
                KinesisEvent.Record kinesisRecord = kinesisEventRecord.getKinesis();
                curRecordSequenceNumber = kinesisRecord.getSequenceNumber();

            } catch (Exception e) {
                /* Since we are working with streams, we can return the failed item immediately.
                   Lambda will immediately begin to retry processing from this failed item onwards. */
                batchItemFailures.add(new StreamsEventResponse.BatchItemFailure(curRecordSequenceNumber));
                return new StreamsEventResponse(batchItemFailures);
            }
        }
       
       return new StreamsEventResponse(batchItemFailures);   
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/blob/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Javascript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
exports.handler = async (event, context) => {
  for (const record of event.Records) {
    try {
      console.log(`Processed Kinesis Event - EventID: ${record.eventID}`);
      const recordData = await getRecordDataAsync(record.kinesis);
      console.log(`Record Data: ${recordData}`);
      // TODO: Do interesting work based on the new data
    } catch (err) {
      console.error(`An error occurred ${err}`);
      /* Since we are working with streams, we can return the failed item immediately.
            Lambda will immediately begin to retry processing from this failed item onwards. */
      return {
        batchItemFailures: [{ itemIdentifier: record.kinesis.sequenceNumber }],
      };
    }
  }
  console.log(`Successfully processed ${event.Records.length} records.`);
  return { batchItemFailures: [] };
};

async function getRecordDataAsync(payload) {
  var data = Buffer.from(payload.data, "base64").toString("utf-8");
  await Promise.resolve(1); //Placeholder for actual async work
  return data;
}
```
Reporting Kinesis batch item failures with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import {
  KinesisStreamEvent,
  Context,
  KinesisStreamHandler,
  KinesisStreamRecordPayload,
  KinesisStreamBatchResponse,
} from "aws-lambda";
import { Buffer } from "buffer";
import { Logger } from "@aws-lambda-powertools/logger";

const logger = new Logger({
  logLevel: "INFO",
  serviceName: "kinesis-stream-handler-sample",
});

export const functionHandler: KinesisStreamHandler = async (
  event: KinesisStreamEvent,
  context: Context
): Promise<KinesisStreamBatchResponse> => {
  for (const record of event.Records) {
    try {
      logger.info(`Processed Kinesis Event - EventID: ${record.eventID}`);
      const recordData = await getRecordDataAsync(record.kinesis);
      logger.info(`Record Data: ${recordData}`);
      // TODO: Do interesting work based on the new data
    } catch (err) {
      logger.error(`An error occurred ${err}`);
      /* Since we are working with streams, we can return the failed item immediately.
            Lambda will immediately begin to retry processing from this failed item onwards. */
      return {
        batchItemFailures: [{ itemIdentifier: record.kinesis.sequenceNumber }],
      };
    }
  }
  logger.info(`Successfully processed ${event.Records.length} records.`);
  return { batchItemFailures: [] };
};

async function getRecordDataAsync(
  payload: KinesisStreamRecordPayload
): Promise<string> {
  var data = Buffer.from(payload.data, "base64").toString("utf-8");
  await Promise.resolve(1); //Placeholder for actual async work
  return data;
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using PHP.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
<?php

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\Kinesis\KinesisEvent;
use Bref\Event\Handler as StdHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler implements StdHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handle(mixed $event, Context $context): array
    {
        $kinesisEvent = new KinesisEvent($event);
        $this->logger->info("Processing records");
        $records = $kinesisEvent->getRecords();

        $failedRecords = [];
        foreach ($records as $record) {
            try {
                $data = $record->getData();
                $this->logger->info(json_encode($data));
                // TODO: Do interesting work based on the new data
            } catch (Exception $e) {
                $this->logger->error($e->getMessage());
                // failed processing the record
                $failedRecords[] = $record->getSequenceNumber();
            }
        }
        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords records");

        // change format for the response
        $failures = array_map(
            fn(string $sequenceNumber) => ['itemIdentifier' => $sequenceNumber],
            $failedRecords
        );

        return [
            'batchItemFailures' => $failures
        ];
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def handler(event, context):
    records = event.get("Records")
    curRecordSequenceNumber = ""
    
    for record in records:
        try:
            # Process your record
            curRecordSequenceNumber = record["kinesis"]["sequenceNumber"]
        except Exception as e:
            # Return failed record's sequence number
            return {"batchItemFailures":[{"itemIdentifier": curRecordSequenceNumber}]}

    return {"batchItemFailures":[]}
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Ruby.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'aws-sdk'

def lambda_handler(event:, context:)
  batch_item_failures = []

  event['Records'].each do |record|
    begin
      puts "Processed Kinesis Event - EventID: #{record['eventID']}"
      record_data = get_record_data_async(record['kinesis'])
      puts "Record Data: #{record_data}"
      # TODO: Do interesting work based on the new data
    rescue StandardError => err
      puts "An error occurred #{err}"
      # Since we are working with streams, we can return the failed item immediately.
      # Lambda will immediately begin to retry processing from this failed item onwards.
      return { batchItemFailures: [{ itemIdentifier: record['kinesis']['sequenceNumber'] }] }
    end
  end

  puts "Successfully processed #{event['Records'].length} records."
  { batchItemFailures: batch_item_failures }
end

def get_record_data_async(payload)
  data = Base64.decode64(payload['data']).force_encoding('utf-8')
  # Placeholder for actual async work
  sleep(1)
  data
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository. 
Reporting Kinesis batch item failures with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::{
    event::kinesis::KinesisEvent,
    kinesis::KinesisEventRecord,
    streams::{KinesisBatchItemFailure, KinesisEventResponse},
};
use lambda_runtime::{run, service_fn, Error, LambdaEvent};

async fn function_handler(event: LambdaEvent<KinesisEvent>) -> Result<KinesisEventResponse, Error> {
    let mut response = KinesisEventResponse {
        batch_item_failures: vec![],
    };

    if event.payload.records.is_empty() {
        tracing::info!("No records found. Exiting.");
        return Ok(response);
    }

    for record in &event.payload.records {
        tracing::info!(
            "EventId: {}",
            record.event_id.as_deref().unwrap_or_default()
        );

        let record_processing_result = process_record(record);

        if record_processing_result.is_err() {
            response.batch_item_failures.push(KinesisBatchItemFailure {
                item_identifier: record.kinesis.sequence_number.clone(),
            });
            /* Since we are working with streams, we can return the failed item immediately.
            Lambda will immediately begin to retry processing from this failed item onwards. */
            return Ok(response);
        }
    }

    tracing::info!(
        "Successfully processed {} records",
        event.payload.records.len()
    );

    Ok(response)
}

fn process_record(record: &KinesisEventRecord) -> Result<(), Error> {
    let record_data = std::str::from_utf8(record.kinesis.data.as_slice());

    if let Some(err) = record_data.err() {
        tracing::error!("Error: {}", err);
        return Err(Error::from(err));
    }

    let record_data = record_data.unwrap_or_default();

    // do something interesting with the data
    tracing::info!("Data: {}", record_data);

    Ok(())
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        // disable printing the name of the module in every log line.
        .with_target(false)
        // disabling time is handy because CloudWatch will add the ingestion time.
        .without_time()
        .init();

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Reporting batch item failures for Lambda functions with a DynamoDB trigger
<a name="example_serverless_DynamoDB_Lambda_batch_item_failures_section"></a>

The following code examples show how to implement partial batch response for Lambda functions that receive events from a DynamoDB stream. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using System.Text.Json;
using System.Text;
using Amazon.Lambda.Core;
using Amazon.Lambda.DynamoDBEvents;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace AWSLambda_DDB;

public class Function
{
    public StreamsEventResponse FunctionHandler(DynamoDBEvent dynamoEvent, ILambdaContext context)

    {
        context.Logger.LogInformation($"Beginning to process {dynamoEvent.Records.Count} records...");
        List<StreamsEventResponse.BatchItemFailure> batchItemFailures = new List<StreamsEventResponse.BatchItemFailure>();
        StreamsEventResponse streamsEventResponse = new StreamsEventResponse();

        foreach (var record in dynamoEvent.Records)
        {
            try
            {
                var sequenceNumber = record.Dynamodb.SequenceNumber;
                context.Logger.LogInformation(sequenceNumber);
            }
            catch (Exception ex)
            {
                context.Logger.LogError(ex.Message);
                batchItemFailures.Add(new StreamsEventResponse.BatchItemFailure() { ItemIdentifier = record.Dynamodb.SequenceNumber });
            }
        }

        if (batchItemFailures.Count > 0)
        {
            streamsEventResponse.BatchItemFailures = batchItemFailures;
        }

        context.Logger.LogInformation("Stream processing complete.");
        return streamsEventResponse;
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

type BatchItemFailure struct {
	ItemIdentifier string `json:"ItemIdentifier"`
}

type BatchResult struct {
	BatchItemFailures []BatchItemFailure `json:"BatchItemFailures"`
}

func HandleRequest(ctx context.Context, event events.DynamoDBEvent) (*BatchResult, error) {
	var batchItemFailures []BatchItemFailure
	curRecordSequenceNumber := ""

	for _, record := range event.Records {
		// Process your record
		curRecordSequenceNumber = record.Change.SequenceNumber
	}

	if curRecordSequenceNumber != "" {
		batchItemFailures = append(batchItemFailures, BatchItemFailure{ItemIdentifier: curRecordSequenceNumber})
	}
	
	batchResult := BatchResult{
		BatchItemFailures: batchItemFailures,
	}

	return &batchResult, nil
}

func main() {
	lambda.Start(HandleRequest)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.DynamodbEvent;
import com.amazonaws.services.lambda.runtime.events.StreamsEventResponse;
import com.amazonaws.services.lambda.runtime.events.models.dynamodb.StreamRecord;

import java.util.ArrayList;
import java.util.List;

public class ProcessDynamodbRecords implements RequestHandler<DynamodbEvent, StreamsEventResponse> {

    @Override
    public StreamsEventResponse handleRequest(DynamodbEvent input, Context context) {

        List<StreamsEventResponse.BatchItemFailure> batchItemFailures = new ArrayList<>();
        String curRecordSequenceNumber = "";

        for (DynamodbEvent.DynamodbStreamRecord dynamodbStreamRecord : input.getRecords()) {
          try {
                //Process your record
                StreamRecord dynamodbRecord = dynamodbStreamRecord.getDynamodb();
                curRecordSequenceNumber = dynamodbRecord.getSequenceNumber();
                
            } catch (Exception e) {
                /* Since we are working with streams, we can return the failed item immediately.
                   Lambda will immediately begin to retry processing from this failed item onwards. */
                batchItemFailures.add(new StreamsEventResponse.BatchItemFailure(curRecordSequenceNumber));
                return new StreamsEventResponse(batchItemFailures);
            }
        }
       
       return new StreamsEventResponse();   
    }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using JavaScript.  

```
export const handler = async (event) => {
  const records = event.Records;
  let curRecordSequenceNumber = "";

  for (const record of records) {
    try {
      // Process your record
      curRecordSequenceNumber = record.dynamodb.SequenceNumber;
    } catch (e) {
      // Return failed record's sequence number
      return { batchItemFailures: [{ itemIdentifier: curRecordSequenceNumber }] };
    }
  }

  return { batchItemFailures: [] };
};
```
Reporting DynamoDB batch item failures with Lambda using TypeScript.  

```
import {
  DynamoDBBatchResponse,
  DynamoDBBatchItemFailure,
  DynamoDBStreamEvent,
} from "aws-lambda";

export const handler = async (
  event: DynamoDBStreamEvent
): Promise<DynamoDBBatchResponse> => {
  const batchItemFailures: DynamoDBBatchItemFailure[] = [];
  let curRecordSequenceNumber;

  for (const record of event.Records) {
    curRecordSequenceNumber = record.dynamodb?.SequenceNumber;

    if (curRecordSequenceNumber) {
      batchItemFailures.push({
        itemIdentifier: curRecordSequenceNumber,
      });
    }
  }

  return { batchItemFailures: batchItemFailures };
};
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using PHP.  

```
<?php

# using bref/bref and bref/logger for simplicity

use Bref\Context\Context;
use Bref\Event\DynamoDb\DynamoDbEvent;
use Bref\Event\Handler as StdHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler implements StdHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handle(mixed $event, Context $context): array
    {
        $dynamoDbEvent = new DynamoDbEvent($event);
        $this->logger->info("Processing records");

        $records = $dynamoDbEvent->getRecords();
        $failedRecords = [];
        foreach ($records as $record) {
            try {
                $data = $record->getData();
                $this->logger->info(json_encode($data));
                // TODO: Do interesting work based on the new data
            } catch (Exception $e) {
                $this->logger->error($e->getMessage());
                // failed processing the record
                $failedRecords[] = $record->getSequenceNumber();
            }
        }
        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords records");

        // change format for the response
        $failures = array_map(
            fn(string $sequenceNumber) => ['itemIdentifier' => $sequenceNumber],
            $failedRecords
        );

        return [
            'batchItemFailures' => $failures
        ];
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def handler(event, context):
    records = event.get("Records")
    curRecordSequenceNumber = ""
    
    for record in records:
        try:
            # Process your record
            curRecordSequenceNumber = record["dynamodb"]["SequenceNumber"]
        except Exception as e:
            # Return failed record's sequence number
            return {"batchItemFailures":[{"itemIdentifier": curRecordSequenceNumber}]}

    return {"batchItemFailures":[]}
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using Ruby.  

```
def lambda_handler(event:, context:)
    records = event["Records"]
    cur_record_sequence_number = ""
  
    records.each do |record|
      begin
        # Process your record
        cur_record_sequence_number = record["dynamodb"]["SequenceNumber"]
      rescue StandardError => e
        # Return failed record's sequence number
        return {"batchItemFailures" => [{"itemIdentifier" => cur_record_sequence_number}]}
      end
    end
  
    {"batchItemFailures" => []}
  end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository. 
Reporting DynamoDB batch item failures with Lambda using Rust.  

```
use aws_lambda_events::{
    event::dynamodb::{Event, EventRecord, StreamRecord},
    streams::{DynamoDbBatchItemFailure, DynamoDbEventResponse},
};
use lambda_runtime::{run, service_fn, Error, LambdaEvent};

/// Process the stream record
fn process_record(record: &EventRecord) -> Result<(), Error> {
    let stream_record: &StreamRecord = &record.change;

    // process your stream record here...
    tracing::info!("Data: {:?}", stream_record);

    Ok(())
}

/// Main Lambda handler here...
async fn function_handler(event: LambdaEvent<Event>) -> Result<DynamoDbEventResponse, Error> {
    let mut response = DynamoDbEventResponse {
        batch_item_failures: vec![],
    };

    let records = &event.payload.records;

    if records.is_empty() {
        tracing::info!("No records found. Exiting.");
        return Ok(response);
    }

    for record in records {
        tracing::info!("EventId: {}", record.event_id);

        // Couldn't find a sequence number
        if record.change.sequence_number.is_none() {
            response.batch_item_failures.push(DynamoDbBatchItemFailure {
                item_identifier: Some("".to_string()),
            });
            return Ok(response);
        }

        // Process your record here...
        if process_record(record).is_err() {
            response.batch_item_failures.push(DynamoDbBatchItemFailure {
                item_identifier: record.change.sequence_number.clone(),
            });
            /* Since we are working with streams, we can return the failed item immediately.
            Lambda will immediately begin to retry processing from this failed item onwards. */
            return Ok(response);
        }
    }

    tracing::info!("Successfully processed {} record(s)", records.len());

    Ok(response)
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::INFO)
        // disable printing the name of the module in every log line.
        .with_target(false)
        // disabling time is handy because CloudWatch will add the ingestion time.
        .without_time()
        .init();

    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# Reporting batch item failures for Lambda functions with an Amazon SQS trigger
<a name="example_serverless_SQS_Lambda_batch_item_failures_section"></a>

The following code examples show how to implement partial batch response for Lambda functions that receive events from an SQS queue. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.

------
#### [ .NET ]

**SDK for .NET**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using .NET.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
using Amazon.Lambda.Core;
using Amazon.Lambda.SQSEvents;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]
namespace sqsSample;

public class Function
{
    public async Task<SQSBatchResponse> FunctionHandler(SQSEvent evnt, ILambdaContext context)
    {
        List<SQSBatchResponse.BatchItemFailure> batchItemFailures = new List<SQSBatchResponse.BatchItemFailure>();
        foreach(var message in evnt.Records)
        {
            try
            {
                //process your message
                await ProcessMessageAsync(message, context);
            }
            catch (System.Exception)
            {
                //Add failed message identifier to the batchItemFailures list
                batchItemFailures.Add(new SQSBatchResponse.BatchItemFailure{ItemIdentifier=message.MessageId}); 
            }
        }
        return new SQSBatchResponse(batchItemFailures);
    }

    private async Task ProcessMessageAsync(SQSEvent.SQSMessage message, ILambdaContext context)
    {
        if (String.IsNullOrEmpty(message.Body))
        {
            throw new Exception("No Body in SQS Message.");
        }
        context.Logger.LogInformation($"Processed message {message.Body}");
        // TODO: Do interesting work based on the new message
        await Task.CompletedTask;
    }
}
```

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using Go.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
package main

import (
	"context"
	"fmt"
	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
)

func handler(ctx context.Context, sqsEvent events.SQSEvent) (map[string]interface{}, error) {
	batchItemFailures := []map[string]interface{}{}

	for _, message := range sqsEvent.Records {
		if len(message.Body) > 0 {
			// Your message processing condition here
			fmt.Printf("Successfully processed message: %s\n", message.Body)
		} else {
			// Message processing failed
			fmt.Printf("Failed to process message %s\n", message.MessageId)
			batchItemFailures = append(batchItemFailures, map[string]interface{}{"itemIdentifier": message.MessageId})
		}
	}

	sqsBatchResponse := map[string]interface{}{
		"batchItemFailures": batchItemFailures,
	}
	return sqsBatchResponse, nil
}

func main() {
	lambda.Start(handler)
}
```

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using Java.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
import com.amazonaws.services.lambda.runtime.events.SQSEvent;
import com.amazonaws.services.lambda.runtime.events.SQSBatchResponse;
 
import java.util.ArrayList;
import java.util.List;
 
public class ProcessSQSMessageBatch implements RequestHandler<SQSEvent, SQSBatchResponse> {
    @Override
    public SQSBatchResponse handleRequest(SQSEvent sqsEvent, Context context) {
         List<SQSBatchResponse.BatchItemFailure> batchItemFailures = new ArrayList<SQSBatchResponse.BatchItemFailure>();

         for (SQSEvent.SQSMessage message : sqsEvent.getRecords()) {
             try {
                 //process your message
             } catch (Exception e) {
                 //Add failed message identifier to the batchItemFailures list
                 batchItemFailures.add(new SQSBatchResponse.BatchItemFailure(message.getMessageId()));
             }
         }
         return new SQSBatchResponse(batchItemFailures);
     }
}
```

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using JavaScript.  

```
// Node.js 20.x Lambda runtime, AWS SDK for Javascript V3
export const handler = async (event, context) => {
    const batchItemFailures = [];
    for (const record of event.Records) {
        try {
            await processMessageAsync(record, context);
        } catch (error) {
            batchItemFailures.push({ itemIdentifier: record.messageId });
        }
    }
    return { batchItemFailures };
};

async function processMessageAsync(record, context) {
    if (record.body && record.body.includes("error")) {
        throw new Error("There is an error in the SQS Message.");
    }
    console.log(`Processed message: ${record.body}`);
}
```
Reporting SQS batch item failures with Lambda using TypeScript.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
import { SQSEvent, SQSBatchResponse, Context, SQSBatchItemFailure, SQSRecord } from 'aws-lambda';

export const handler = async (event: SQSEvent, context: Context): Promise<SQSBatchResponse> => {
    const batchItemFailures: SQSBatchItemFailure[] = [];

    for (const record of event.Records) {
        try {
            await processMessageAsync(record);
        } catch (error) {
            batchItemFailures.push({ itemIdentifier: record.messageId });
        }
    }

    return {batchItemFailures: batchItemFailures};
};

async function processMessageAsync(record: SQSRecord): Promise<void> {
    if (record.body && record.body.includes("error")) {
        throw new Error('There is an error in the SQS Message.');
    }
    console.log(`Processed message ${record.body}`);
}
```

------
#### [ PHP ]

**SDK for PHP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using PHP.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
<?php

use Bref\Context\Context;
use Bref\Event\Sqs\SqsEvent;
use Bref\Event\Sqs\SqsHandler;
use Bref\Logger\StderrLogger;

require __DIR__ . '/vendor/autoload.php';

class Handler extends SqsHandler
{
    private StderrLogger $logger;
    public function __construct(StderrLogger $logger)
    {
        $this->logger = $logger;
    }

    /**
     * @throws JsonException
     * @throws \Bref\Event\InvalidLambdaEvent
     */
    public function handleSqs(SqsEvent $event, Context $context): void
    {
        $this->logger->info("Processing SQS records");
        $records = $event->getRecords();

        foreach ($records as $record) {
            try {
                // Assuming the SQS message is in JSON format
                $message = json_decode($record->getBody(), true);
                $this->logger->info(json_encode($message));
                // TODO: Implement your custom processing logic here
            } catch (Exception $e) {
                $this->logger->error($e->getMessage());
                // failed processing the record
                $this->markAsFailed($record);
            }
        }
        $totalRecords = count($records);
        $this->logger->info("Successfully processed $totalRecords SQS records");
    }
}

$logger = new StderrLogger();
return new Handler($logger);
```

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using Python.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0

def lambda_handler(event, context):
    if event:
        batch_item_failures = []
        sqs_batch_response = {}
     
        for record in event["Records"]:
            try:
                print(f"Processed message: {record['body']}")
            except Exception as e:
                batch_item_failures.append({"itemIdentifier": record['messageId']})
        
        sqs_batch_response["batchItemFailures"] = batch_item_failures
        return sqs_batch_response
```

------
#### [ Ruby ]

**SDK for Ruby**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda-with-batch-item-handling) repository. 
Reporting SQS batch item failures with Lambda using Ruby.  

```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'json'

def lambda_handler(event:, context:)
  if event
    batch_item_failures = []
    sqs_batch_response = {}

    event["Records"].each do |record|
      begin
        # process message
      rescue StandardError => e
        batch_item_failures << {"itemIdentifier" => record['messageId']}
      end
    end

    sqs_batch_response["batchItemFailures"] = batch_item_failures
    return sqs_batch_response
  end
end
```

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-sqs-report-batch-item-failures) repository. 
Reporting SQS batch item failures with Lambda using Rust.  

```
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
use aws_lambda_events::{
    event::sqs::{SqsBatchResponse, SqsEvent},
    sqs::{BatchItemFailure, SqsMessage},
};
use lambda_runtime::{run, service_fn, Error, LambdaEvent};

async fn process_record(_: &SqsMessage) -> Result<(), Error> {
    Err(Error::from("Error processing message"))
}

async fn function_handler(event: LambdaEvent<SqsEvent>) -> Result<SqsBatchResponse, Error> {
    let mut batch_item_failures = Vec::new();
    for record in event.payload.records {
        match process_record(&record).await {
            Ok(_) => (),
            Err(_) => batch_item_failures.push(BatchItemFailure {
                item_identifier: record.message_id.unwrap(),
            }),
        }
    }

    Ok(SqsBatchResponse {
        batch_item_failures,
    })
}

#[tokio::main]
async fn main() -> Result<(), Error> {
    run(service_fn(function_handler)).await
}
```

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.

# AWS community contributions for Lambda
<a name="service_code_examples_aws_community_contributions"></a>

*AWS community contributions* are examples that were created and are maintained by multiple teams across AWS. To provide feedback, use the mechanism provided in the linked repositories.

**Topics**
+ [Build and test a serverless application](example_tributary-lite_serverless-application_section.md)

# Build and test a serverless application
<a name="example_tributary-lite_serverless-application_section"></a>

The following code examples show how to build and test a serverless application using API Gateway with Lambda and DynamoDB

------
#### [ .NET ]

**SDK for .NET**  
 Shows how to build and test a serverless application that consists of an API Gateway with Lambda and DynamoDB using the .NET SDK.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/aws-samples/serverless-dotnet-demo).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda

------
#### [ Go ]

**SDK for Go V2**  
 Shows how to build and test a serverless application that consists of an API Gateway with Lambda and DynamoDB using the Go SDK.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/aws-samples/serverless-go-demo).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda

------
#### [ Java ]

**SDK for Java 2.x**  
 Shows how to build and test a serverless application that consists of an API Gateway with Lambda and DynamoDB using the Java SDK.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/aws-samples/serverless-java-frameworks-samples).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda

------
#### [ Rust ]

**SDK for Rust**  
 Shows how to build and test a serverless application that consists of an API Gateway with Lambda and DynamoDB using the Rust SDK.   
 For complete source code and instructions on how to set up and run, see the full example on [GitHub](https://github.com/aws-samples/serverless-rust-demo).   

**Services used in this example**
+ API Gateway
+ DynamoDB
+ Lambda

------

For a complete list of AWS SDK developer guides and code examples, see [Using Lambda with an AWS SDK](sdk-general-information-section.md). This topic also includes information about getting started and details about previous SDK versions.