Setup

1. Install the Mergify CLI, see the CLI installation guide for instructions.

2. GitHub authentication: Stacks needs access to create PRs. Either:

   • Set the GITHUB_TOKEN environment variable, or
   • Install the GitHub CLI and run gh auth login

3. Enable “Automatically delete head branches” in your GitHub repository settings (Settings > General > Pull Requests). When a stacked PR merges, this cleans up its remote branch automatically so the next PR in the chain can rebase onto main cleanly.

Run the setup command in your Git repository:

mergify stack setup

This installs:

• A commit-msg Git hook that automatically generates a Change-Id for every new commit. The Change-Id is how Stacks tracks the relationship between your local commits and their GitHub pull requests.

• A pre-push hook that warns you if you accidentally use git push instead of mergify stack push.

Mergify CLI provides AI skills that teach coding agents how to work with Stacks — so they automatically use mergify stack push instead of git push, amend commits instead of creating fixup commits, and follow stack conventions.

This works with Claude Code, Cursor, and many other AI agents:

npx skills add Mergifyio/mergify-cli

From the official marketplace:

/plugin install mergify@claude-plugins-official

Or from the repository:

/plugin marketplace add Mergifyio/mergify-cli
/plugin install mergify

Create a test commit to confirm the hook is active:

echo "test" >> test.txt
git add test.txt
git commit -m "test: verify stack setup"

Check the commit message:

git log -1

You should see a Change-Id trailer at the bottom of the message:

test: verify stack setup

Change-Id: Ia1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2

Clean up the test commit if you don’t need it:

git reset HEAD~1

These optional Git config settings let you customize Stacks behavior:

Example:

git config mergify-cli.stack-create-as-draft true

Head to Creating Stacks to push your first stack.