Act
by nektos
Test GitHub Actions Workflows on Your Local Machine
Debug and validate CI/CD pipelines locally before pushing to GitHub, saving time and reducing trial-and-error commits.
- 68,291+ GitHub stars
- Built with Go
- Execute GitHub Actions workflows locally using Docker containers
- MIT License license
About This Project
Act brings GitHub Actions execution to your local development environment, eliminating the frustrating cycle of pushing commits just to test workflow changes. Built with Go, this powerful tool replicates the GitHub Actions runtime environment using Docker containers, allowing you to run jobs and workflows exactly as they would execute on GitHub's servers.
The tool solves a critical pain point in modern DevOps workflows: the slow feedback loop when developing CI/CD pipelines. Instead of waiting for cloud runners and cluttering your commit history with "fix CI" messages, you can iterate rapidly on your local machine, catching configuration errors and logic issues before they reach your repository.
Act supports multiple runner images, secret management, and event simulation, making it possible to test complex workflows involving different triggers, matrix builds, and environment configurations. The tool intelligently maps your local filesystem to the container environment, ensuring your code changes are immediately reflected during testing.
With over 68,000 stars on GitHub, act has become an essential tool for teams practicing infrastructure-as-code and maintaining robust CI/CD pipelines. It dramatically reduces cloud compute costs associated with iterative workflow development while improving developer productivity and confidence in deployment automation.
Key Features
- Execute GitHub Actions workflows locally using Docker containers
- Support for multiple runner images and custom Docker images
- Simulate different GitHub event triggers and webhook payloads
- Manage secrets and environment variables for local testing
- Run specific jobs or entire workflows with command-line flexibility
How You Can Use It
Debug failing GitHub Actions workflows without pushing test commits
Validate CI/CD pipeline changes locally before code review
Develop and test complex multi-job workflows with dependencies
Train team members on GitHub Actions in an offline environment
Reduce cloud runner costs by testing workflows locally first
Who Is This For?
DevOps engineers, CI/CD pipeline developers, and software teams using GitHub Actions for automation