The AWS Serverless Application Model (AWS SAM) transform is a AWS CloudFormation macro that transforms SAM templates into CloudFormation templates.
To use the SAM transform, add AWS::Serverless-2016-10-31 to the Transform section of your CloudFormation template.
Benefits of using the SAM transform include:
- Built-in best practices and sane defaults.
- Local testing and debugging with the AWS SAM CLI.
- Extension of the CloudFormation template syntax.
Save the following as template.yaml:
Transform: AWS::Serverless-2016-10-31 Resources: MyFunction: Type: AWS::Serverless::Function Properties: Runtime: nodejs24.x Handler: index.handler InlineCode: | exports.handler = async (event) => { console.log(event); }
And deploy it with the SAM CLI:
sam sync --stack-name sam-app
The AWS::Serverless::Function resource will create a AWS Lambda function that logs events it receives.
Under the hood, the template is transformed into the JSON equivalent of the following CloudFormation template:
Resources: MyFunction: Type: AWS::Lambda::Function Properties: Code: ZipFile: | exports.handler = async (event) => { console.log(event); } Handler: index.handler Role: !GetAtt MyFunctionRole.Arn Runtime: nodejs24.x Tags: - Key: lambda:createdBy Value: SAM MyFunctionRole: Type: AWS::IAM::Role Properties: AssumeRolePolicyDocument: Version: "2012-10-17" Statement: - Action: - sts:AssumeRole Effect: Allow Principal: Service: - lambda.amazonaws.com ManagedPolicyArns: - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole Tags: - Key: lambda:createdBy Value: SAM
For a more thorough introduction, see the this tutorial in the Developer Guide.
You'll need to have Python 3.8+ installed.
Create a virtual environment:
python3 -m venv .venv
source .venv/bin/activateSet up dependencies:
make init
Run tests:
make pr
See DEVELOPMENT_GUIDE.md for further development instructions, and CONTRIBUTING.md for the contributing guidelines.
The best way to interact with the team is through GitHub. You can either create an issue or start a discussion.
You can also join the #samdev channel on Slack.