Resource policy example for AWS SAM

You can control access to your APIs by attaching a resource policy within your AWS SAM template. To do this, you use the ApiAuth data type.

The following is an example AWS SAM template for a private API. A private API must have a resource policy to deploy.

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  MyPrivateApi:
    Type: AWS::Serverless::Api
    Properties:
      StageName: Prod
      EndpointConfiguration: PRIVATE  # Creates a private API. Resource policies are required for all private APIs.
      Auth:
        ResourcePolicy:
          CustomStatements: 
            - Effect: 'Allow'
              Action: 'execute-api:Invoke'
              Resource: ['execute-api:/*/*/*']
              Principal: '*'
            - Effect: 'Deny'
              Action: 'execute-api:Invoke'
              Resource: ['execute-api:/*/*/*']
              Principal: '*'
  MyFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      InlineCode: |
        def handler(event, context):
          return {'body': 'Hello World!', 'statusCode': 200}
      Handler: index.handler
      Runtime: python3.10
      Events:
        AddItem:
          Type: Api
          Properties:
            RestApiId: 
              Ref: MyPrivateApi
            Path: /
            Method: get

For more information about resource policies, see Controlling access to an API with API Gateway resource policies in the API Gateway Developer Guide. For more information about private APIs, see Creating a private API in Amazon API Gateway in the API Gateway Developer Guide.