commit-coach

Catches the git commit calls Claude makes and fixes two things before they land:

1. Attribution. Co-Authored-By: trailers and 🤖 Generated with ... lines are taken out of the message. Claude is also no longer told to add them, so they mostly stop showing up at all.
2. Lazy subjects. A subject like fix, wip, update, stuff, a single word, anything over 72 characters, or anything without a conventional prefix (feat|fix|chore|docs|refactor|test|perf|build|ci|style) is rewritten from the actual diff by a fast model:

commit-coach: 'fix' → 'fix(scheduler): handle empty slot list'

Your own body is kept if you wrote one; the model only adds a short body when there was none. If the model's answer is not a clean conventional subject of 72 characters or less, your message goes through as it was, and a toast says so.

It reads every way a message gets into a commit: -m, several -m, -m"...", --message=, -am, $'...', the -m "$(cat <<'EOF' ... EOF)" heredoc agents like to use, -F file, and -F - fed by a heredoc. The new message goes back in as plain single-quoted -m arguments; everything else in the command (git add -A && ... && git push) is left exactly as it was.

It leaves a commit entirely alone while a merge is in progress (MERGE_HEAD exists), for --amend without a new message, -C/-c/--fixup/--squash, and when the shell builds the message at run time ("$MSG", "$(git log ...)"). Subjects starting with Merge , Revert ", fixup! or squash! are never rewritten.

Install

claude --plugin-dir ./commit-coach

or add this repo as a marketplace and install it with /plugin.

Options

| option | default | what it does | | --- | --- | --- | | stripAttribution | true | Remove Co-Authored-By: and "Generated with" lines, and empty the commit attribution text Claude is given. Note: this strips every Co-Authored-By: trailer, a human pair's included. | | rewriteSubjects | true | Rewrite lazy subjects from the diff. | | model | haiku | The model that writes the new subject: an alias or a full model id. |

How it works

A tool.call hook on Bash lexes the command (keeping each token's position), reads the commit message, and when it needs a new subject runs git diff --cached (or git diff HEAD after -a or a git add in the same command) and asks $.model.complete; it then calls next({ ...e, command }) with the rewritten command, and adds a note to the result so Claude knows the new message is intended and doesn't amend it back. An attribution.text hook for commit answers an empty string.

Only the first git commit in a command is coached.