Step Functions examples using AWS SDK for .NET

namespace StepFunctionsActions;

using Amazon.StepFunctions;
using Amazon.StepFunctions.Model;

public class HelloStepFunctions
{
    static async Task Main()
    {
        var stepFunctionsClient = new AmazonStepFunctionsClient();

        Console.Clear();
        Console.WriteLine("Welcome to AWS Step Functions");
        Console.WriteLine("Let's list up to 10 of your state machines:");
        var stateMachineListRequest = new ListStateMachinesRequest { MaxResults = 10 };

        // Get information for up to 10 Step Functions state machines.
        var response = await stepFunctionsClient.ListStateMachinesAsync(stateMachineListRequest);

        if (response.StateMachines.Count > 0)
        {
            response.StateMachines.ForEach(stateMachine =>
            {
                Console.WriteLine($"State Machine Name: {stateMachine.Name}\tAmazon Resource Name (ARN): {stateMachine.StateMachineArn}");
            });
        }
        else
        {
            Console.WriteLine("\tNo state machines were found.");
        }
    }
}

Run an interactive scenario at a command prompt.

global using System.Text.Json;
global using Amazon.StepFunctions;
global using Microsoft.Extensions.Configuration;
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;
global using StepFunctionsActions;
global using LogLevel = Microsoft.Extensions.Logging.LogLevel;



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

namespace StepFunctionsBasics;

public class StepFunctionsBasics
{
    private static ILogger _logger = null!;
    private static IConfigurationRoot _configuration = null!;
    private static IAmazonIdentityManagementService _iamService = null!;

    static async Task Main(string[] args)
    {
        // Set up dependency injection for AWS Step Functions.
        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<IAmazonStepFunctions>()
                    .AddAWSService<IAmazonIdentityManagementService>()
                    .AddTransient<StepFunctionsWrapper>()
            )
            .Build();

        _logger = LoggerFactory.Create(builder => { builder.AddConsole(); })
            .CreateLogger<StepFunctionsBasics>();

        // Load configuration settings.
        _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();

        var activityName = _configuration["ActivityName"];
        var stateMachineName = _configuration["StateMachineName"];

        var roleName = _configuration["RoleName"];
        var repoBaseDir = _configuration["RepoBaseDir"];
        var jsonFilePath = _configuration["JsonFilePath"];
        var jsonFileName = _configuration["JsonFileName"];

        var uiMethods = new UiMethods();
        var stepFunctionsWrapper = host.Services.GetRequiredService<StepFunctionsWrapper>();

        _iamService = host.Services.GetRequiredService<IAmazonIdentityManagementService>();

        // Load definition for the state machine from a JSON file.
        var stateDefinitionJson = File.ReadAllText($"{repoBaseDir}{jsonFilePath}{jsonFileName}");

        Console.Clear();
        uiMethods.DisplayOverview();
        uiMethods.PressEnter();

        uiMethods.DisplayTitle("Create activity");
        Console.WriteLine("Let's start by creating an activity.");
        string activityArn;
        string stateMachineArn;

        // Check to see if the activity already exists.
        var activityList = await stepFunctionsWrapper.ListActivitiesAsync();
        var existingActivity = activityList.FirstOrDefault(activity => activity.Name == activityName);
        if (existingActivity is not null)
        {
            activityArn = existingActivity.ActivityArn;
            Console.WriteLine($"Activity, {activityName}, already exists.");
        }
        else
        {
            activityArn = await stepFunctionsWrapper.CreateActivity(activityName);
        }

        // Swap the placeholder in the JSON file with the Amazon Resource Name (ARN)
        // of the recently created activity.
        var stateDefinition = stateDefinitionJson.Replace("{{DOC_EXAMPLE_ACTIVITY_ARN}}", activityArn);

        uiMethods.DisplayTitle("Create state machine");
        Console.WriteLine("Now we'll create a state machine.");

        // Find or create an IAM role that can be assumed by Step Functions.
        var role = await GetOrCreateStateMachineRole(roleName);

        // See if the state machine already exists.
        var stateMachineList = await stepFunctionsWrapper.ListStateMachinesAsync();
        var existingStateMachine =
            stateMachineList.FirstOrDefault(stateMachine => stateMachine.Name == stateMachineName);
        if (existingStateMachine is not null)
        {
            Console.WriteLine($"State machine, {stateMachineName}, already exists.");
            stateMachineArn = existingStateMachine.StateMachineArn;
        }
        else
        {
            // Create the state machine.
            stateMachineArn =
                await stepFunctionsWrapper.CreateStateMachine(stateMachineName, stateDefinition, role.Arn);
            uiMethods.PressEnter();
        }

        Console.WriteLine("The state machine has been created.");
        var describeStateMachineResponse = await stepFunctionsWrapper.DescribeStateMachineAsync(stateMachineArn);

        Console.WriteLine($"{describeStateMachineResponse.Name}\t{describeStateMachineResponse.StateMachineArn}");
        Console.WriteLine($"Current status: {describeStateMachineResponse.Status}");
        Console.WriteLine($"Amazon Resource Name (ARN) of the role assumed by the state machine: {describeStateMachineResponse.RoleArn}");

        var userName = string.Empty;
        Console.Write("Before we start the state machine, tell me what should ChatSFN call you? ");
        userName = Console.ReadLine();

        // Keep asking until the user enters a string value.
        while (string.IsNullOrEmpty(userName))
        {
            Console.Write("Enter your name: ");
            userName = Console.ReadLine();
        }

        var executionJson = @"{""name"": """ + userName + @"""}";

        // Start the state machine execution.
        Console.WriteLine("Now we'll start execution of the state machine.");
        var executionArn = await stepFunctionsWrapper.StartExecutionAsync(executionJson, stateMachineArn);
        Console.WriteLine("State machine started.");

        Console.WriteLine($"Thank you, {userName}. Now let's get started...");
        uiMethods.PressEnter();

        uiMethods.DisplayTitle("ChatSFN");

        var isDone = false;
        var response = new GetActivityTaskResponse();
        var taskToken = string.Empty;
        var userChoice = string.Empty;

        while (!isDone)
        {
            response = await stepFunctionsWrapper.GetActivityTaskAsync(activityArn, "MvpWorker");
            taskToken = response.TaskToken;

            // Parse the returned JSON string.
            var taskJsonResponse = JsonDocument.Parse(response.Input);
            var taskJsonObject = taskJsonResponse.RootElement;
            var message = taskJsonObject.GetProperty("message").GetString();
            var actions = taskJsonObject.GetProperty("actions").EnumerateArray().Select(x => x.ToString()).ToList();
            Console.WriteLine($"\n{message}\n");

            // Prompt the user for another choice.
            Console.WriteLine("ChatSFN: What would you like me to do?");
            actions.ForEach(action => Console.WriteLine($"\t{action}"));
            Console.Write($"\n{userName}, tell me your choice: ");
            userChoice = Console.ReadLine();
            if (userChoice?.ToLower() == "done")
            {
                isDone = true;
            }

            Console.WriteLine($"You have selected: {userChoice}");
            var jsonResponse = @"{""action"": """ + userChoice + @"""}";

            await stepFunctionsWrapper.SendTaskSuccessAsync(taskToken, jsonResponse);
        }

        await stepFunctionsWrapper.StopExecution(executionArn);
        Console.WriteLine("Now we will wait for the execution to stop.");
        DescribeExecutionResponse executionResponse;
        do
        {
            executionResponse = await stepFunctionsWrapper.DescribeExecutionAsync(executionArn);
        } while (executionResponse.Status == ExecutionStatus.RUNNING);

        Console.WriteLine("State machine stopped.");
        uiMethods.PressEnter();

        uiMethods.DisplayTitle("State machine executions");
        Console.WriteLine("Now let's take a look at the execution values for the state machine.");

        // List the executions.
        var executions = await stepFunctionsWrapper.ListExecutionsAsync(stateMachineArn);

        uiMethods.DisplayTitle("Step function execution values");
        executions.ForEach(execution =>
        {
            Console.WriteLine($"{execution.Name}\t{execution.StartDate} to {execution.StopDate}");
        });

        uiMethods.PressEnter();

        // Now delete the state machine and the activity.
        uiMethods.DisplayTitle("Clean up resources");
        Console.WriteLine("Deleting the state machine...");

        await stepFunctionsWrapper.DeleteStateMachine(stateMachineArn);
        Console.WriteLine("State machine deleted.");

        Console.WriteLine("Deleting the activity...");
        await stepFunctionsWrapper.DeleteActivity(activityArn);
        Console.WriteLine("Activity deleted.");

        Console.WriteLine("The Amazon Step Functions scenario is now complete.");
    }

    static async Task<Role> GetOrCreateStateMachineRole(string roleName)
    {
        // Define the policy document for the role.
        var stateMachineRolePolicy = @"{
         ""Version"": ""2012-10-17"",
        ""Statement"": [{
            ""Sid"": """",
            ""Effect"": ""Allow"",
            ""Principal"": {
                ""Service"": ""states.amazonaws.com""},
            ""Action"": ""sts:AssumeRole""}]}";

        var role = new Role();
        var roleExists = false;

        try
        {
            var getRoleResponse = await _iamService.GetRoleAsync(new GetRoleRequest { RoleName = roleName });
            roleExists = true;
            role = getRoleResponse.Role;
        }
        catch (NoSuchEntityException)
        {
            // The role doesn't exist. Create it.
            Console.WriteLine($"Role, {roleName} doesn't exist. Creating it...");
        }

        if (!roleExists)
        {
            var request = new CreateRoleRequest
            {
                RoleName = roleName,
                AssumeRolePolicyDocument = stateMachineRolePolicy,
            };

            var createRoleResponse = await _iamService.CreateRoleAsync(request);
            role = createRoleResponse.Role;
        }

        return role;
    }
}


namespace StepFunctionsBasics;

/// <summary>
/// Some useful methods to make screen display easier.
/// </summary>
public class UiMethods
{
    private readonly string _sepBar = new('-', Console.WindowWidth);

    /// <summary>
    /// Show information about the scenario.
    /// </summary>
    public void DisplayOverview()
    {
        Console.Clear();
        DisplayTitle("Welcome to the AWS Step Functions Demo");

        Console.WriteLine("This example application will do the following:");
        Console.WriteLine("\t 1. Create an activity.");
        Console.WriteLine("\t 2. Create a state machine.");
        Console.WriteLine("\t 3. Start an execution.");
        Console.WriteLine("\t 4. Run the worker, then stop it.");
        Console.WriteLine("\t 5. List executions.");
        Console.WriteLine("\t 6. Clean up the resources created for the example.");
    }

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

    /// <summary>
    /// Pad a string with spaces to center it on the console display.
    /// </summary>
    /// <param name="strToCenter"></param>
    /// <returns></returns>
    private 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);
    }
}

Define a class that wraps state machine and activity actions.

namespace StepFunctionsActions;

using Amazon.StepFunctions;
using Amazon.StepFunctions.Model;

/// <summary>
/// Wrapper that performs AWS Step Functions actions.
/// </summary>
public class StepFunctionsWrapper
{
    private readonly IAmazonStepFunctions _amazonStepFunctions;

    /// <summary>
    /// The constructor for the StepFunctionsWrapper. Initializes the
    /// client object passed to it.
    /// </summary>
    /// <param name="amazonStepFunctions">An initialized Step Functions client object.</param>
    public StepFunctionsWrapper(IAmazonStepFunctions amazonStepFunctions)
    {
        _amazonStepFunctions = amazonStepFunctions;
    }

    /// <summary>
    /// Create a Step Functions activity using the supplied name.
    /// </summary>
    /// <param name="activityName">The name for the new Step Functions activity.</param>
    /// <returns>The Amazon Resource Name (ARN) for the new activity.</returns>
    public async Task<string> CreateActivity(string activityName)
    {
        var response = await _amazonStepFunctions.CreateActivityAsync(new CreateActivityRequest { Name = activityName });
        return response.ActivityArn;
    }


    /// <summary>
    /// Create a Step Functions state machine.
    /// </summary>
    /// <param name="stateMachineName">Name for the new Step Functions state
    /// machine.</param>
    /// <param name="definition">A JSON string that defines the Step Functions
    /// state machine.</param>
    /// <param name="roleArn">The Amazon Resource Name (ARN) of the role.</param>
    /// <returns></returns>
    public async Task<string> CreateStateMachine(string stateMachineName, string definition, string roleArn)
    {
        var request = new CreateStateMachineRequest
        {
            Name = stateMachineName,
            Definition = definition,
            RoleArn = roleArn
        };

        var response =
            await _amazonStepFunctions.CreateStateMachineAsync(request);
        return response.StateMachineArn;
    }


    /// <summary>
    /// Delete a Step Machine activity.
    /// </summary>
    /// <param name="activityArn">The Amazon Resource Name (ARN) of
    /// the activity.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> DeleteActivity(string activityArn)
    {
        var response = await _amazonStepFunctions.DeleteActivityAsync(new DeleteActivityRequest { ActivityArn = activityArn });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }


    /// <summary>
    /// Delete a Step Functions state machine.
    /// </summary>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// state machine.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> DeleteStateMachine(string stateMachineArn)
    {
        var response = await _amazonStepFunctions.DeleteStateMachineAsync(new DeleteStateMachineRequest
        { StateMachineArn = stateMachineArn });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }


    /// <summary>
    /// Retrieve information about the specified Step Functions execution.
    /// </summary>
    /// <param name="executionArn">The Amazon Resource Name (ARN) of the
    /// Step Functions execution.</param>
    /// <returns>The API response returned by the API.</returns>
    public async Task<DescribeExecutionResponse> DescribeExecutionAsync(string executionArn)
    {
        var response = await _amazonStepFunctions.DescribeExecutionAsync(new DescribeExecutionRequest { ExecutionArn = executionArn });
        return response;
    }


    /// <summary>
    /// Retrieve information about the specified Step Functions state machine.
    /// </summary>
    /// <param name="StateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine to retrieve.</param>
    /// <returns>Information about the specified Step Functions state machine.</returns>
    public async Task<DescribeStateMachineResponse> DescribeStateMachineAsync(string StateMachineArn)
    {
        var response = await _amazonStepFunctions.DescribeStateMachineAsync(new DescribeStateMachineRequest { StateMachineArn = StateMachineArn });
        return response;
    }


    /// <summary>
    /// Retrieve a task with the specified Step Functions activity
    /// with the specified Amazon Resource Name (ARN).
    /// </summary>
    /// <param name="activityArn">The Amazon Resource Name (ARN) of
    /// the Step Functions activity.</param>
    /// <param name="workerName">The name of the Step Functions worker.</param>
    /// <returns>The response from the Step Functions activity.</returns>
    public async Task<GetActivityTaskResponse> GetActivityTaskAsync(string activityArn, string workerName)
    {
        var response = await _amazonStepFunctions.GetActivityTaskAsync(new GetActivityTaskRequest
        { ActivityArn = activityArn, WorkerName = workerName });
        return response;
    }


    /// <summary>
    /// List the Step Functions activities for the current account.
    /// </summary>
    /// <returns>A list of ActivityListItems.</returns>
    public async Task<List<ActivityListItem>> ListActivitiesAsync()
    {
        var request = new ListActivitiesRequest();
        var activities = new List<ActivityListItem>();

        do
        {
            var response = await _amazonStepFunctions.ListActivitiesAsync(request);

            if (response.NextToken is not null)
            {
                request.NextToken = response.NextToken;
            }

            activities.AddRange(response.Activities);
        }
        while (request.NextToken is not null);

        return activities;
    }


    /// <summary>
    /// Retrieve information about executions of a Step Functions
    /// state machine.
    /// </summary>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine.</param>
    /// <returns>A list of ExecutionListItem objects.</returns>
    public async Task<List<ExecutionListItem>> ListExecutionsAsync(string stateMachineArn)
    {
        var executions = new List<ExecutionListItem>();
        ListExecutionsResponse response;
        var request = new ListExecutionsRequest { StateMachineArn = stateMachineArn };

        do
        {
            response = await _amazonStepFunctions.ListExecutionsAsync(request);
            executions.AddRange(response.Executions);
            if (response.NextToken is not null)
            {
                request.NextToken = response.NextToken;
            }
        } while (response.NextToken is not null);

        return executions;
    }


    /// <summary>
    /// Retrieve a list of Step Functions state machines.
    /// </summary>
    /// <returns>A list of StateMachineListItem objects.</returns>
    public async Task<List<StateMachineListItem>> ListStateMachinesAsync()
    {
        var stateMachines = new List<StateMachineListItem>();
        var listStateMachinesPaginator =
            _amazonStepFunctions.Paginators.ListStateMachines(new ListStateMachinesRequest());

        await foreach (var response in listStateMachinesPaginator.Responses)
        {
            stateMachines.AddRange(response.StateMachines);
        }

        return stateMachines;
    }


    /// <summary>
    /// Indicate that the Step Functions task, indicated by the
    /// task token, has completed successfully.
    /// </summary>
    /// <param name="taskToken">Identifies the task.</param>
    /// <param name="taskResponse">The response received from executing the task.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> SendTaskSuccessAsync(string taskToken, string taskResponse)
    {
        var response = await _amazonStepFunctions.SendTaskSuccessAsync(new SendTaskSuccessRequest
        { TaskToken = taskToken, Output = taskResponse });

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


    /// <summary>
    /// Start execution of an AWS Step Functions state machine.
    /// </summary>
    /// <param name="executionName">The name to use for the execution.</param>
    /// <param name="executionJson">The JSON string to pass for execution.</param>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine.</param>
    /// <returns>The Amazon Resource Name (ARN) of the AWS Step Functions
    /// execution.</returns>
    public async Task<string> StartExecutionAsync(string executionJson, string stateMachineArn)
    {
        var executionRequest = new StartExecutionRequest
        {
            Input = executionJson,
            StateMachineArn = stateMachineArn
        };

        var response = await _amazonStepFunctions.StartExecutionAsync(executionRequest);
        return response.ExecutionArn;
    }


    /// <summary>
    /// Stop execution of a Step Functions workflow.
    /// </summary>
    /// <param name="executionArn">The Amazon Resource Name (ARN) of
    /// the Step Functions execution to stop.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> StopExecution(string executionArn)
    {
        var response =
            await _amazonStepFunctions.StopExecutionAsync(new StopExecutionRequest { ExecutionArn = executionArn });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }


}

    /// <summary>
    /// Create a Step Functions activity using the supplied name.
    /// </summary>
    /// <param name="activityName">The name for the new Step Functions activity.</param>
    /// <returns>The Amazon Resource Name (ARN) for the new activity.</returns>
    public async Task<string> CreateActivity(string activityName)
    {
        var response = await _amazonStepFunctions.CreateActivityAsync(new CreateActivityRequest { Name = activityName });
        return response.ActivityArn;
    }

    /// <summary>
    /// Create a Step Functions state machine.
    /// </summary>
    /// <param name="stateMachineName">Name for the new Step Functions state
    /// machine.</param>
    /// <param name="definition">A JSON string that defines the Step Functions
    /// state machine.</param>
    /// <param name="roleArn">The Amazon Resource Name (ARN) of the role.</param>
    /// <returns></returns>
    public async Task<string> CreateStateMachine(string stateMachineName, string definition, string roleArn)
    {
        var request = new CreateStateMachineRequest
        {
            Name = stateMachineName,
            Definition = definition,
            RoleArn = roleArn
        };

        var response =
            await _amazonStepFunctions.CreateStateMachineAsync(request);
        return response.StateMachineArn;
    }

    /// <summary>
    /// Delete a Step Machine activity.
    /// </summary>
    /// <param name="activityArn">The Amazon Resource Name (ARN) of
    /// the activity.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> DeleteActivity(string activityArn)
    {
        var response = await _amazonStepFunctions.DeleteActivityAsync(new DeleteActivityRequest { ActivityArn = activityArn });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }

    /// <summary>
    /// Delete a Step Functions state machine.
    /// </summary>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// state machine.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> DeleteStateMachine(string stateMachineArn)
    {
        var response = await _amazonStepFunctions.DeleteStateMachineAsync(new DeleteStateMachineRequest
        { StateMachineArn = stateMachineArn });
        return response.HttpStatusCode == System.Net.HttpStatusCode.OK;
    }

    /// <summary>
    /// Retrieve information about the specified Step Functions execution.
    /// </summary>
    /// <param name="executionArn">The Amazon Resource Name (ARN) of the
    /// Step Functions execution.</param>
    /// <returns>The API response returned by the API.</returns>
    public async Task<DescribeExecutionResponse> DescribeExecutionAsync(string executionArn)
    {
        var response = await _amazonStepFunctions.DescribeExecutionAsync(new DescribeExecutionRequest { ExecutionArn = executionArn });
        return response;
    }

    /// <summary>
    /// Retrieve information about the specified Step Functions state machine.
    /// </summary>
    /// <param name="StateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine to retrieve.</param>
    /// <returns>Information about the specified Step Functions state machine.</returns>
    public async Task<DescribeStateMachineResponse> DescribeStateMachineAsync(string StateMachineArn)
    {
        var response = await _amazonStepFunctions.DescribeStateMachineAsync(new DescribeStateMachineRequest { StateMachineArn = StateMachineArn });
        return response;
    }

    /// <summary>
    /// Retrieve a task with the specified Step Functions activity
    /// with the specified Amazon Resource Name (ARN).
    /// </summary>
    /// <param name="activityArn">The Amazon Resource Name (ARN) of
    /// the Step Functions activity.</param>
    /// <param name="workerName">The name of the Step Functions worker.</param>
    /// <returns>The response from the Step Functions activity.</returns>
    public async Task<GetActivityTaskResponse> GetActivityTaskAsync(string activityArn, string workerName)
    {
        var response = await _amazonStepFunctions.GetActivityTaskAsync(new GetActivityTaskRequest
        { ActivityArn = activityArn, WorkerName = workerName });
        return response;
    }

    /// <summary>
    /// List the Step Functions activities for the current account.
    /// </summary>
    /// <returns>A list of ActivityListItems.</returns>
    public async Task<List<ActivityListItem>> ListActivitiesAsync()
    {
        var request = new ListActivitiesRequest();
        var activities = new List<ActivityListItem>();

        do
        {
            var response = await _amazonStepFunctions.ListActivitiesAsync(request);

            if (response.NextToken is not null)
            {
                request.NextToken = response.NextToken;
            }

            activities.AddRange(response.Activities);
        }
        while (request.NextToken is not null);

        return activities;
    }

    /// <summary>
    /// Retrieve information about executions of a Step Functions
    /// state machine.
    /// </summary>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine.</param>
    /// <returns>A list of ExecutionListItem objects.</returns>
    public async Task<List<ExecutionListItem>> ListExecutionsAsync(string stateMachineArn)
    {
        var executions = new List<ExecutionListItem>();
        ListExecutionsResponse response;
        var request = new ListExecutionsRequest { StateMachineArn = stateMachineArn };

        do
        {
            response = await _amazonStepFunctions.ListExecutionsAsync(request);
            executions.AddRange(response.Executions);
            if (response.NextToken is not null)
            {
                request.NextToken = response.NextToken;
            }
        } while (response.NextToken is not null);

        return executions;
    }

    /// <summary>
    /// Retrieve a list of Step Functions state machines.
    /// </summary>
    /// <returns>A list of StateMachineListItem objects.</returns>
    public async Task<List<StateMachineListItem>> ListStateMachinesAsync()
    {
        var stateMachines = new List<StateMachineListItem>();
        var listStateMachinesPaginator =
            _amazonStepFunctions.Paginators.ListStateMachines(new ListStateMachinesRequest());

        await foreach (var response in listStateMachinesPaginator.Responses)
        {
            stateMachines.AddRange(response.StateMachines);
        }

        return stateMachines;
    }

    /// <summary>
    /// Indicate that the Step Functions task, indicated by the
    /// task token, has completed successfully.
    /// </summary>
    /// <param name="taskToken">Identifies the task.</param>
    /// <param name="taskResponse">The response received from executing the task.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> SendTaskSuccessAsync(string taskToken, string taskResponse)
    {
        var response = await _amazonStepFunctions.SendTaskSuccessAsync(new SendTaskSuccessRequest
        { TaskToken = taskToken, Output = taskResponse });

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

    /// <summary>
    /// Start execution of an AWS Step Functions state machine.
    /// </summary>
    /// <param name="executionName">The name to use for the execution.</param>
    /// <param name="executionJson">The JSON string to pass for execution.</param>
    /// <param name="stateMachineArn">The Amazon Resource Name (ARN) of the
    /// Step Functions state machine.</param>
    /// <returns>The Amazon Resource Name (ARN) of the AWS Step Functions
    /// execution.</returns>
    public async Task<string> StartExecutionAsync(string executionJson, string stateMachineArn)
    {
        var executionRequest = new StartExecutionRequest
        {
            Input = executionJson,
            StateMachineArn = stateMachineArn
        };

        var response = await _amazonStepFunctions.StartExecutionAsync(executionRequest);
        return response.ExecutionArn;
    }