Act
Overview
Act runs GitHub Actions workflows locally using Docker. Test and debug CI pipelines without pushing to GitHub. Supports most GitHub Actions features.
Instructions
Step 1: Install
bashbrew install act
Step 2: Run Workflows
bashact # run push event act pull_request # run PR event act -j test # run specific job act -W .github/workflows/ci.yml # specific workflow act --secret-file .env.secrets # with secrets
Step 3: Configuration
bash# .actrc — Default settings -P ubuntu-latest=catthehacker/ubuntu:act-latest --env-file .env
Step 4: Debug
bashact -n # dry run act -v # verbose act -l # list workflows
Guidelines
- First run downloads Docker images (~1-3GB).
- Not all GitHub Actions features work locally (e.g., OIDC tokens).
- Use micro images for faster runs.
- Great for iterating on CI without waiting for GitHub runners.

