Reference an OpenAPI specification external file

This example uses Application Composer from the console to reference an external OpenAPI specification file that defines a API Gateway REST API.

First, create a new project from the Application Composer home page.

Next, activate local sync by selecting Activate local sync from the Menu. Create a new folder named demo, allow the prompt to view files, and select Activate. When prompted, select Save changes.

Next, drag an Amazon API Gateway card onto the canvas. Select Details to bring up the Resource properties panel.

From the Resource properties panel, configure the following and save.

This creates the following directory on our local machine:

demo
└── api-spec.yaml

Now, you can configure the external file on our local machine. Using our IDE, open the api-spec.yaml located in your project folder. Replace its contents with the following:

openapi: '3.0'
info: {}
paths:
  /:
    get:
      responses: {}
    post:
      x-amazon-apigateway-integration:
        credentials:
          Fn::GetAtt:
            - ApiQueuesendmessageRole
            - Arn
        httpMethod: POST
        type: aws
        uri:
          Fn::Sub: arn:${AWS::Partition}:apigateway:${AWS::Region}:sqs:path/${AWS::AccountId}/${Queue.QueueName}
        requestParameters:
          integration.request.header.Content-Type: '''application/x-www-form-urlencoded'''
        requestTemplates:
          application/json: Action=SendMessage&MessageBody={"data":$input.body}
        responses:
          default:
            statusCode: 200
      responses:
        '200':
          description: 200 response

In the Application Composer Template view, you can see that Application Composer has automatically updated your template to reference the external file.