Act vs Codemod

act is an open-source command-line tool that runs GitHub Actions workflows locally using Docker containers. It reads workflow files from .github/workflows/ and executes them with environment variables and filesystem configurations matching GitHub's hosted runners. The tool enables fast local feedback on workflow changes without requiring commits and pushes to a remote repository.

Codemod is an open-source tool for automating large-scale code transformations and refactoring across entire codebases. It enables developers to apply changes programmatically using AST-based patterns.