There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Scenarios for API Gateway using AWS SDKs
<a name="api-gateway_code_examples_scenarios"></a>

The following code examples show you how to implement common scenarios in API Gateway with AWS SDKs. These scenarios show you how to accomplish specific tasks by calling multiple functions within API Gateway 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**
+ [Create a REST API to track COVID-19 data](api-gateway_example_cross_ApiGatewayDataTracker_section.md)
+ [Create a REST API with Lambda proxy integration](api-gateway_example_api_gateway_GettingStarted_087_section.md)
+ [Create a lending library REST API](api-gateway_example_cross_AuroraRestLendingLibrary_section.md)
+ [Create a serverless application to manage photos](api-gateway_example_cross_PAM_section.md)
+ [Create a websocket chat application](api-gateway_example_cross_ApiGatewayWebsocketChat_section.md)
+ [Create and deploy a REST API](api-gateway_example_api-gateway_Usage_CreateDeployRest_section.md)
+ [Use API Gateway to invoke a Lambda function](api-gateway_example_cross_LambdaAPIGateway_section.md)

# Create an API Gateway REST API to track COVID-19 data
<a name="api-gateway_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

------

# Create a REST API with Lambda proxy integration
<a name="api-gateway_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)

------

# Create a lending library REST API
<a name="api-gateway_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

------

# Create a photo asset management application that lets users manage photos using labels
<a name="api-gateway_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

------

# Create a websocket chat application with API Gateway
<a name="api-gateway_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

------

# Create and deploy a REST API using an AWS SDK
<a name="api-gateway_example_api-gateway_Usage_CreateDeployRest_section"></a>

The following code example shows how to:
+ Create a REST API served by API Gateway.
+ Add resources to the REST API to represent a user profile.
+ Add integration methods so that the REST API uses a DynamoDB table to store user profile data.
+ Send HTTP requests to the REST API to add and retrieve user profiles.

------
#### [ 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/api-gateway#code-examples). 
Create a class that wraps API Gateway operations.  

```
import argparse
import json
import logging
from pprint import pprint
import boto3
from botocore.exceptions import ClientError
import requests

logger = logging.getLogger(__name__)


class ApiGatewayToService:
    """
    Encapsulates Amazon API Gateway functions that are used to create a REST API that
    integrates with another AWS service.
    """

    def __init__(self, apig_client):
        """
        :param apig_client: A Boto3 API Gateway client.
        """
        self.apig_client = apig_client
        self.api_id = None
        self.root_id = None
        self.stage = None


    def create_rest_api(self, api_name):
        """
        Creates a REST API on API Gateway. The default API has only a root resource
        and no HTTP methods.

        :param api_name: The name of the API. This descriptive name is not used in
                         the API path.
        :return: The ID of the newly created API.
        """
        try:
            result = self.apig_client.create_rest_api(name=api_name)
            self.api_id = result["id"]
            logger.info("Created REST API %s with ID %s.", api_name, self.api_id)
        except ClientError:
            logger.exception("Couldn't create REST API %s.", api_name)
            raise

        try:
            result = self.apig_client.get_resources(restApiId=self.api_id)
            self.root_id = next(
                item for item in result["items"] if item["path"] == "/"
            )["id"]
        except ClientError:
            logger.exception("Couldn't get resources for API %s.", self.api_id)
            raise
        except StopIteration as err:
            logger.exception("No root resource found in API %s.", self.api_id)
            raise ValueError from err

        return self.api_id


    def add_rest_resource(self, parent_id, resource_path):
        """
        Adds a resource to a REST API.

        :param parent_id: The ID of the parent resource.
        :param resource_path: The path of the new resource, relative to the parent.
        :return: The ID of the new resource.
        """
        try:
            result = self.apig_client.create_resource(
                restApiId=self.api_id, parentId=parent_id, pathPart=resource_path
            )
            resource_id = result["id"]
            logger.info("Created resource %s.", resource_path)
        except ClientError:
            logger.exception("Couldn't create resource %s.", resource_path)
            raise
        else:
            return resource_id


    def add_integration_method(
        self,
        resource_id,
        rest_method,
        service_endpoint_prefix,
        service_action,
        service_method,
        role_arn,
        mapping_template,
    ):
        """
        Adds an integration method to a REST API. An integration method is a REST
        resource, such as '/users', and an HTTP verb, such as GET. The integration
        method is backed by an AWS service, such as Amazon DynamoDB.

        :param resource_id: The ID of the REST resource.
        :param rest_method: The HTTP verb used with the REST resource.
        :param service_endpoint_prefix: The service endpoint that is integrated with
                                        this method, such as 'dynamodb'.
        :param service_action: The action that is called on the service, such as
                               'GetItem'.
        :param service_method: The HTTP method of the service request, such as POST.
        :param role_arn: The Amazon Resource Name (ARN) of a role that grants API
                         Gateway permission to use the specified action with the
                         service.
        :param mapping_template: A mapping template that is used to translate REST
                                 elements, such as query parameters, to the request
                                 body format required by the service.
        """
        service_uri = (
            f"arn:aws:apigateway:{self.apig_client.meta.region_name}"
            f":{service_endpoint_prefix}:action/{service_action}"
        )
        try:
            self.apig_client.put_method(
                restApiId=self.api_id,
                resourceId=resource_id,
                httpMethod=rest_method,
                authorizationType="NONE",
            )
            self.apig_client.put_method_response(
                restApiId=self.api_id,
                resourceId=resource_id,
                httpMethod=rest_method,
                statusCode="200",
                responseModels={"application/json": "Empty"},
            )
            logger.info("Created %s method for resource %s.", rest_method, resource_id)
        except ClientError:
            logger.exception(
                "Couldn't create %s method for resource %s.", rest_method, resource_id
            )
            raise

        try:
            self.apig_client.put_integration(
                restApiId=self.api_id,
                resourceId=resource_id,
                httpMethod=rest_method,
                type="AWS",
                integrationHttpMethod=service_method,
                credentials=role_arn,
                requestTemplates={"application/json": json.dumps(mapping_template)},
                uri=service_uri,
                passthroughBehavior="WHEN_NO_TEMPLATES",
            )
            self.apig_client.put_integration_response(
                restApiId=self.api_id,
                resourceId=resource_id,
                httpMethod=rest_method,
                statusCode="200",
                responseTemplates={"application/json": ""},
            )
            logger.info(
                "Created integration for resource %s to service URI %s.",
                resource_id,
                service_uri,
            )
        except ClientError:
            logger.exception(
                "Couldn't create integration for resource %s to service URI %s.",
                resource_id,
                service_uri,
            )
            raise


    def deploy_api(self, stage_name):
        """
        Deploys a REST API. After a REST API is deployed, it can be called from any
        REST client, such as the Python Requests package or Postman.

        :param stage_name: The stage of the API to deploy, such as 'test'.
        :return: The base URL of the deployed REST API.
        """
        try:
            self.apig_client.create_deployment(
                restApiId=self.api_id, stageName=stage_name
            )
            self.stage = stage_name
            logger.info("Deployed stage %s.", stage_name)
        except ClientError:
            logger.exception("Couldn't deploy stage %s.", stage_name)
            raise
        else:
            return self.api_url()



    def api_url(self, resource=None):
        """
        Builds the REST API URL from its parts.

        :param resource: The resource path to append to the base URL.
        :return: The REST URL to the specified resource.
        """
        url = (
            f"https://{self.api_id}.execute-api.{self.apig_client.meta.region_name}"
            f".amazonaws.com/{self.stage}"
        )
        if resource is not None:
            url = f"{url}/{resource}"
        return url
```
Deploy a REST API and call it with the Requests package.  

```
def usage_demo(table_name, role_name, rest_api_name):
    """
    Demonstrates how to used API Gateway to create and deploy a REST API, and how
    to use the Requests package to call it.

    :param table_name: The name of the demo DynamoDB table.
    :param role_name: The name of the demo role that grants API Gateway permission to
                      call DynamoDB.
    :param rest_api_name: The name of the demo REST API created by the demo.
    """
    gateway = ApiGatewayToService(boto3.client("apigateway"))
    role = boto3.resource("iam").Role(role_name)

    print("Creating REST API in API Gateway.")
    gateway.create_rest_api(rest_api_name)

    print("Adding resources to the REST API.")
    profiles_id = gateway.add_rest_resource(gateway.root_id, "profiles")
    username_id = gateway.add_rest_resource(profiles_id, "{username}")

    # The DynamoDB service requires that all integration requests use POST.
    print("Adding integration methods to read and write profiles in Amazon DynamoDB.")
    gateway.add_integration_method(
        profiles_id,
        "GET",
        "dynamodb",
        "Scan",
        "POST",
        role.arn,
        {"TableName": table_name},
    )
    gateway.add_integration_method(
        profiles_id,
        "POST",
        "dynamodb",
        "PutItem",
        "POST",
        role.arn,
        {
            "TableName": table_name,
            "Item": {
                "username": {"S": "$input.path('$.username')"},
                "name": {"S": "$input.path('$.name')"},
                "title": {"S": "$input.path('$.title')"},
            },
        },
    )
    gateway.add_integration_method(
        username_id,
        "GET",
        "dynamodb",
        "GetItem",
        "POST",
        role.arn,
        {
            "TableName": table_name,
            "Key": {"username": {"S": "$method.request.path.username"}},
        },
    )

    stage = "test"
    print(f"Deploying the {stage} stage.")
    gateway.deploy_api(stage)

    profiles_url = gateway.api_url("profiles")
    print(
        f"Using the Requests package to post some people to the profiles REST API at "
        f"{profiles_url}."
    )
    requests.post(
        profiles_url,
        json={"username": "will", "name": "William Shakespeare", "title": "playwright"},
    )
    requests.post(
        profiles_url,
        json={
            "username": "ludwig",
            "name": "Ludwig van Beethoven",
            "title": "composer",
        },
    )
    requests.post(
        profiles_url,
        json={"username": "jane", "name": "Jane Austen", "title": "author"},
    )
    print("Getting the list of profiles from the REST API.")
    profiles = requests.get(profiles_url).json()
    pprint(profiles)
    print(f"Getting just the profile for username 'jane' (URL: {profiles_url}/jane).")
    jane = requests.get(f"{profiles_url}/jane").json()
    pprint(jane)
```
+ For API details, see the following topics in *AWS SDK for Python (Boto3) API Reference*.
  + [CreateDeployment](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateDeployment)
  + [CreateResource](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateResource)
  + [CreateRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/CreateRestApi)
  + [DeleteRestApi](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/DeleteRestApi)
  + [GetResources](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetResources)
  + [GetRestApis](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/GetRestApis)
  + [PutIntegration](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegration)
  + [PutIntegrationResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutIntegrationResponse)
  + [PutMethod](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethod)
  + [PutMethodResponse](https://docs.aws.amazon.com/goto/boto3/apigateway-2015-07-09/PutMethodResponse)

------

# Use API Gateway to invoke a Lambda function
<a name="api-gateway_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

------