nocoauthor

A git commit-msg hook that strips AI co-author trailers from your commit messages.

Coding agents append a trailer to every commit they make:

Co-Authored-By: Claude <[email protected]>

Some people want that. Some people don't, and turning it off means finding the right setting in every tool separately — and hoping each one honours it. This hook works one layer down, at git itself, so it applies no matter what produced the commit: an agent, an IDE, or you.

Install

Pick whichever you like — all three run the same installer.

npm (no install needed, works on macOS, Linux and Windows):

npx git-nocoauthor install

Shell (no Node required):

curl -fsSL https://raw.githubusercontent.com/Otitodev/nocoauthor/main/bootstrap.sh | sh

From source:

git clone https://github.com/Otitodev/nocoauthor
cd nocoauthor
./install.sh

All of these install globally, for every repository. To limit it to the repo you're standing in, pass --repo:

npx git-nocoauthor install --repo
curl -fsSL https://raw.githubusercontent.com/Otitodev/nocoauthor/main/bootstrap.sh | sh -s -- --repo
./install.sh --repo

Read this before installing globally

Global installation works by setting core.hooksPath, and that setting is exclusive: once set, git ignores every repository's own .git/hooks directory. If any of your projects use husky, lefthook, or pre-commit, their hooks stop firing.

The installer handles this rather than papering over it:

• If core.hooksPath is already set, it installs into that directory and leaves the setting alone. Your existing hooks keep working.
• If it is not set, it warns you and asks before setting it.
• If a different commit-msg hook is already there, it refuses to overwrite and tells you. --force backs the old one up first.

If you'd rather not touch global config at all, use --repo.

Verify

git commit --allow-empty -F - <<'EOF'
Test commit

Co-Authored-By: Claude <[email protected]>
Co-Authored-By: A Human <[email protected]>
EOF

git log -1 --format=%B

The Claude trailer is gone; the human one is untouched.

Configuration

Choose which trailers get stripped — any extended-regex alternation, matched case-insensitively against the trailer line:

git config --global nocoauthor.pattern 'claude|anthropic|copilot|cursor'

Default: claude|anthropic.

Turn it off without uninstalling:

git config --global nocoauthor.enabled false

Bypass it for a single commit:

NOCOAUTHOR=0 git commit -m "..."

What it does not cover

Only commit messages pass through this hook. Pull request descriptions don't — gh pr create never calls git's commit-msg. If your agent adds a "Generated with …" line to PR bodies, turn that off in the tool itself. For Claude Code that's one line in ~/.claude/settings.json:

{ "includeCoAuthoredBy": false }

The two are complementary: the setting stops the trailer being written at all, and this hook catches anything that slips through from other tools.

Uninstall

npx git-nocoauthor uninstall # or, from a clone:
./uninstall.sh               # or: ./uninstall.sh --repo

It removes only a hook it recognises as its own, points you at any backup it made, and unsets core.hooksPath only if it created that directory and nothing else is left in it.

License

MIT