AWS Serverless Application Model 1.165.0

Apply the AWS CloudFormation 2026-08-31 and AWS Lambda 2026-08-30 prompts first. These additional rules cover AWS SAM CLI 1.165.0, its bundled SAM Translator 1.111.0 and Lambda Builders 1.66.0, and SAM template behavior supported by that toolchain.

Toolchain and effective template

• Use the reviewed CLI release and its declared dependencies; for Python installations, use a supported Python 3.10–3.14 interpreter. Match function Runtime, Architectures, and Metadata.BuildMethod to both this CLI's build workflows and Lambda's current support policy; recognition of a deprecated runtime by SAM is not evidence of continued security support.
• Declare Transform: AWS::Serverless-2016-10-31; do not interpret its date or the local CLI pin as a pin of AWS's managed transform implementation.
• Run sam validate --lint --template-file against the selected template. For a completed change set, retrieve CloudFormation GetTemplate with TemplateStage: Processed and review generated resources and OpenAPI security; a successful lint does not establish safe permissions.
• Review merged Globals values for every resource: primitives can be replaced, maps merge, and global list entries are prepended. A resource cannot remove an inherited property; avoid globally sharing layers, environment values, or security groups across different trust boundaries.
• Control --config-file, --config-env, and command-line arguments together. CLI arguments override configuration files, command-specific configuration overrides global configuration, and parameter_overrides overrides