Composite Action Starter

A minimal template for building a composite GitHub Action.

Getting Started

Create a new repository from this template on GitHub using this link.

Or clone it locally and point it at your own remote.

Setup

Install Lefthook, then register the pre-commit hooks:

lefthook install

Customizing the Action

action.yml

Update the action's name, description, branding, inputs/outputs, and steps to match what your action does.

LICENSE

The template ships with the Unlicense (public domain). Replace it with the license you want, or leave it as-is.

Development Workflow

Edit action.yml directly. When you're ready, just commit — the pre-commit hook will automatically format all files using dprint.

If the hook reports errors, fix them and commit again.

CI

.github/workflows/ci.yaml runs two jobs on every push and pull request:

• check — validates the pre-commit hook on Ubuntu
• test — runs the action on Ubuntu, macOS, and Windows

Update the test job to exercise your action's actual inputs and verify its outputs.

Releasing

Tag a release on GitHub:

git tag v1.0.0
git push origin v1.0.0

Then create a GitHub Release from that tag. To make the action discoverable, publish it to the GitHub Marketplace from the release page.