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

Reads the git diff (staged, branch, or provided inline)
Analyzes what files changed, what functions/classes were affected, and the nature of each change

Constructs a Conventional Commits message:

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

<body>

<footer>

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

Type	Usage
`feat`	A new feature
`fix`	A bug fix
`docs`	Documentation only changes
`style`	Formatting, missing semicolons, etc. (no logic)
`refactor`	Code change that neither fixes a bug nor adds a feature
`perf`	Code change that improves performance
`test`	Adding or correcting tests
`chore`	Build, CI, dependencies, tooling
`ci`	CI/CD configuration changes

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.