AWS API Gateway with Step Function

Question

I want a sample to integrate AWS API Gateway with Step Function. I have read this tutorial Creating a Step Functions API Using API Gateway but that tutorial needs me to send

Answer 1

Create your API Gateway resource and method. Then in the "Method Execution" settings, in the Integration Request, use these settings:

• Integration type: AWS Service
• AWS Region: your region
• AWS Service: Step Functions
• AWS Subdomain: your subdomain if you have one - I left it blank
• HTTP method: POST
• Action: StartExecution
• Execution role: needs to be a role with StepFunction start execute policy, such as arn:aws:iam::aws:policy/AWSStepFunctionsFullAccess
• Credentials cache: I left this as default
• Content Handling: Passthrough

Then the magic. Futher down, under Body Mapping Templates:

• Request body passthrough: Never
• Add mapping template : application/json

Futher down in the template text box:

#set($input = $input.json('$'))
{
   "input": "$util.escapeJavaScript($input)",
   "stateMachineArn": "arn:aws:states:eu-west-1:123456789012:stateMachine:yourStepFunctionName"
}

This will pass the json payload posted to API Gateway through to the Step Function.

Omit the execution name so that each call to API Gateway creates a new execution.