Commit Message Writer

Generate conventional, descriptive, and scoped commit messages from your git diffs — no more "fixed bug" or "updated files".

When to Use

✅ USE this skill when:

• "Write a commit message for my staged changes"
• "Generate a commit message from this diff"
• "Rewrite my last commit message to be conventional"
• "Generate changelog-style messages for commits abc..def"
• "Summarize what changed in this branch"
• "Generate messages for all unpushed commits"
• "Check if my commit message follows conventions"

❌ DON'T use this skill when:

• Need sweeping refactors explained → use a code review skill
• Need full changelog generation between releases → use a release tool
• Working on binary-only repos (no meaningful diff)

How It Works

1. Reads the git diff (staged, branch, or provided inline)
2. Analyzes what files changed, what functions/classes were affected, and the nature of each change
3. Constructs a Conventional Commits message:

   <type>(<scope>): <short summary>
   
   <body>
   
   <footer>
   

4. Explains the reasoning so you can review before committing

Available Actions

write:staged

Read git diff --staged and generate a commit message.

Write a commit message for my staged changes

→ Analyzes staged diff, outputs a formatted commit message with type, scope, description, and body.

write:diff

Read changes between the current branch and its base (main/master).

Summarize all changes in this branch as a commit message

write:range

Generate a changelog or multiple commit messages for a range of commits.

Generate conventional commit messages for commits HEAD~5..HEAD

write:provided

Given an inline diff or file list, generate a commit message.

Here's a diff: [...paste diff...]. Write a commit message.

rewrite:last

Improve the last commit message to follow conventions.

Rewrite my last commit message in conventional format

validate

Check whether a message follows Conventional Commits.

Validate this message: "fix(api): handle null pointer in user lookup"

→ Confirms it's valid, or explains what to fix.

Commit Type Reference

Example

User: "Write a commit message for my staged changes"

Assistant: (runs git diff --staged, analyzes changes)

feat(auth): add OAuth2 refresh token rotation

- Implement refresh token rotation on every token refresh
- Invalidate old refresh tokens immediately after use
- Add TTL config for refresh tokens (default 30 days)
- Update token endpoint to return rotated refresh token

Closes: #452

Notes

• Always shows you the proposed message before suggesting you run git commit.
• Respects .gitignore — won't try to diff ignored files.
• For large diffs (>500 lines), summarizes chunk-level changes rather than line-by-line.