edit-commit-message

name	edit-commit-message
description	Run `git commit` (or `--amend`) with the message editor opened in a new tmux pane so the user can hand-edit interactively. Uses git's own editor flow, so `commit.verbose=true` shows the diff as usual. Waits for the editor to close, then continues. Use when the user wants to write or tweak a commit message in vim/nvim. Requires the agent to be running inside a tmux session.

Edit Commit Message Skill

Hand commit-message editing off to nvim in a new tmux pane, then resume once the user saves and quits.

The key idea: don't reinvent git's editor flow. Just point GIT_EDITOR at a tiny wrapper script (shipped alongside this skill) that opens its file argument in a tmux pane and blocks until the pane closes. Git takes care of including the diff, stripping comments, and aborting on empty messages.

When to use

• User asks to edit a proposed commit message themselves.
• User wants to see the diff in the editor (their commit.verbose=true setting just works through this skill).
• Reword / amend flows: git commit --amend, fixing the last message.

For trivial subjects ("typo: fix x") just commit directly via the commit skill — don't bother with this.

Prerequisites

• The agent must inherit $TMUX from the user's session. Without it, the wrapper script bails with a clear error. If $TMUX is empty, ask the user to either run the agent from inside tmux or approve the message in chat.
• The wrapper uses the user's default tmux server (no -L agent) — the pane has to be visible to the user.

How to invoke

GIT_EDITOR="$AGENT_STUFF/skills/edit-commit-message/git-editor.sh" \
  git commit

For amend:

GIT_EDITOR="$AGENT_STUFF/skills/edit-commit-message/git-editor.sh" \
  git commit --amend

Resolve the absolute path to git-editor.sh from this skill's directory — don't hardcode ~/.agent-stuff/... paths into the command, derive them from where SKILL.md lives.

If the user does not have commit.verbose=true in their gitconfig and wants the diff this one time, add -v:

GIT_EDITOR=".../git-editor.sh" git commit -v

What the wrapper does

git-editor.sh is what git invokes in place of vim. It:

1. Refuses to run if $TMUX is unset.
2. Resolves an editor: nvim if available, else vim. (Shell aliases don't apply because tmux runs commands via /bin/sh -c.)
3. tmux split-window runs the editor on the file git passed in, with ; touch <sentinel>; tmux kill-pane appended so the pane closes even when the user has remain-on-exit on.
4. Polls for the sentinel file (normal exit) or pane disappearance (external kill).
5. Returns to git, which then commits / aborts as usual.

Read the script if you need to tweak the split direction or polling: skills/edit-commit-message/git-editor.sh.

Variations

Use a horizontal split or a new window

Edit git-editor.sh and change split-window -v to split-window -h or new-window. The capture / poll logic is the same regardless.

Use with interactive rebase

GIT_EDITOR is also what git uses for the rebase todo list and for reword stops, so this works transparently:

GIT_EDITOR=".../git-editor.sh" git rebase -i HEAD~3

Each editor invocation opens its own pane in turn.

Use as the default editor everywhere

If the user wants this behavior outside the agent too, they can put the script on their GIT_EDITOR permanently in their shell profile. That's their call, not the agent's.

Pitfalls

• No $TMUX. The wrapper exits 1 with a clear message. Don't swallow that — surface it to the user and fall back to approving the message in chat.
• Don't write the message and pass -F -. That was the previous version of this skill, and it bypasses commit.verbose, comment stripping, and the user's normal git hooks. Always go through git commit so git stays in charge.
• Shell aliases don't apply inside the pane. tmux runs commands with /bin/sh -c. The wrapper resolves nvim/vim directly. If nvim plugins still error, check that nvim is on $PATH in the non-interactive shell — set it in .zprofile/.zshenv, not just .zshrc.
• remain-on-exit on would otherwise strand the pane after the editor exits. The wrapper appends tmux kill-pane to defeat this.
• Empty / aborted message. Git itself aborts the commit when the message is empty (or unchanged from the template). The wrapper doesn't need to do anything special.