An example SAM template for a Lambda & API Gateway app that sends messages using SNS

template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An example SAM template for a Lambda & API Gateway app that sends messages using SNS.
Parameters:
  # For any variables you don't want stored in your repo, you can pass them through the SAM deploy command
  # Ie, sam deploy .... --parameter-overrides MyEmail=myemail@gmail.com
  MyEmail:
    Type: String

Resources:
  SendMessageFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      FunctionName: SendMessageFunction
      Handler: SendMessageFunction.lambda_handler
      Runtime: python3.7
      CodeUri: ./SendMessageFunction
      Description: A function that sends a message through SNS when invoked by API Gateway.
      Policies:
      # Read more about SAM policy templates here
      # https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-policy-templates.html
       - SNSPublishMessagePolicy:
           TopicName: !GetAtt MySnsTopic.TopicName
      Environment:
        Variables:
          # Include the SNS topic ARN as an env var so that you can reference it in this function's code.
          SNS_TOPIC_ARN: !Ref MySnsTopic
      Events:
        SendMessageApi:
          # An API Gateway endpoint that responds to HTTP GET
          Type: Api
          Properties:
            Path: /send_message
            Method: GET
            
  MySnsTopic:
    Type: AWS::SNS::Topic
    Properties:
      Subscription: 
      - Protocol: email
        Endpoint: !Ref MyEmail