act

Act is a command-line tool that executes GitHub Actions workflows locally using Docker containers. It reads workflow files from .github/workflows/ directories and recreates the GitHub Actions environment on your local machine, including environment variables and filesystem configurations that match GitHub's hosted runners.

The tool uses the Docker API to pull or build necessary images as defined in workflow files, then determines the execution path based on workflow dependencies. Each action runs in its own container with the same environment setup that GitHub provides. This enables developers to test workflow changes without committing and pushing to trigger remote GitHub Actions runs.

Act serves two primary use cases: providing fast feedback loops for workflow development and functioning as a local task runner that can replace traditional Makefiles. Developers working with GitHub Actions will find this particularly useful for debugging complex workflows, testing new actions, or running CI/CD processes locally during development.

Installation

# via Manual build
make install