website·Indexed Apr 11, 2026
https://nektosact.com/The act tool enables local execution of GitHub Actions workflows defined in .github/workflows/. It leverages the Docker API to build or pull images and run containers that replicate the GitHub-hosted environment variables and filesystem, providing fast feedback and replacing Makefiles.
act is a tool that enables local execution of GitHub Actions workflows defined in .github/workflows/. It allows developers to test their GitHub Actions workflows locally without pushing to GitHub, providing fast feedback during development. The tool replicates the GitHub-hosted environment variables and filesystem, ensuring that actions run the same way locally as they would on GitHub.act without leaving the development environment. See https://sanjulaganepola.github.io/github-local-actions-docs/ for details.act serves two primary purposes: (1) Fast Feedback - developers can test changes to .github/workflows/ files or embedded GitHub actions without committing/pushing, getting immediate local results; (2) Local Task Runner - users can replace their Makefile by using GitHub Actions defined in .github/workflows/ as a local task automation tool.act reads GitHub Actions from .github/workflows/, determines the set of actions to run, and uses the Docker API to either pull or build necessary images as defined in workflow files. It determines execution path based on defined dependencies, then runs containers for each action using the prepared images. Environment variables and filesystem are configured to match what GitHub provides.