Serverless Application Repository

The AWS Serverless Application Repository (SAR) is a managed catalogue of serverless applications that can be found and deployed without being rebuilt. An application in the repository is a SAM template plus its code and metadata, so deploying one creates the CloudFormation stack the template describes — Lambda functions, API Gateway APIs, DynamoDB tables and whatever else it declares — in the deploying account.

Two things make it useful:

• Publishing. An application is published by uploading its code and an AWS SAM template. It can be shared privately with named AWS accounts or across an organisation, or published publicly.
• Reuse as a component. A published application can be referenced from another template as an AWS::Serverless::Application resource, which makes it a nested stack rather than a copied-and-pasted block of YAML.

It is integrated with Lambda: published applications appear in the Lambda console, so a common pattern is a small internal library of vetted, ready-to-deploy building blocks — a standard log forwarder, a webhook handler, an alarm set — that teams deploy rather than reimplement.

Treat a public application the way you would any third-party dependency. Deploying one runs its CloudFormation template in your account with whatever permissions the template requests, so the template is worth reading before it is deployed.