Act

Overview

Act (https://github.com/nektos/act) is an open-source command-line tool that can simulate and run GitHub Actions workflows locally using Docker. It lets you trigger events, run jobs, and debug without pushing to a remote.

Core features and highlights

• Local execution: Run workflows defined in .github/workflows inside local containers.
• Event simulation: Supports triggering push, pull_request, and other events, as well as custom event payloads.
• Matrix and secrets support: Test matrix strategies and inject secrets and environment variables.
• Configurable runner images: Choose or customize Docker images to reproduce different runtime environments.
• Lightweight CLI: Use the act command-line to quickly run a single job or an entire workflow.

Applicable scenarios and target users

Suitable for developers, CI engineers, and open-source maintainers to debug CI configurations locally, quickly validate workflow logic, save the cost of repeated cloud runs, and test workflows offline in private repositories.

Main advantages or highlights

• Fast iteration: No need to wait for a remote runner on every commit