Validate CloudFormation templates before deploy with cfn-lint

Catch CloudFormation schema, region, and intrinsic-function mistakes before a stack update fails in review or deployment.

Prerequisites

Python or cfn-lint binary, CloudFormation templates

Installation

Use the upstream install or setup path that matches your environment:

• pip install cfn-lint. If pip is not available, run
• brew install cfn-lint
• docker build --tag cfn-lint:latest .
• docker run --rm -v pwd:/data cfn-lint:latest /data/template.yaml

Requirements and caveats from upstream:

• <img alt="[cfn-lint logo]" src="https://github.com/aws-cloudformation/cfn-python-lint/blob/main/logo.png?raw=true" width="150" align="right">
• 
• Python 3.10 to 3.14 are supported.

Basic usage or getting-started notes:

• To get information about the SAM Transformation, run the linter with --info

• Pip

• Optional dependencies

• Source: https://github.com/aws-cloudformation/cfn-lint

• Extracted from upstream docs: https://raw.githubusercontent.com/aws-cloudformation/cfn-lint/HEAD/README.md

Documentation

• https://github.com/aws-cloudformation/cfn-lint

Source

• Agent Skill Exchange