Commit Message Generator

Generate commit messages from staged changes following Conventional Commits.

Workflow

Get staged diff
- Run git diff --cached
- If output is empty, inform user there are no staged changes and exit
Generate commit message
- Analyze the diff content
- Apply the rules below to produce a commit message
Confirm and commit
- Display the generated commit message
- Ask user to confirm, edit, or cancel
- Only commit after user confirmation
- Run git commit -m "<message>"

Message Format

<type>(<scope>): <subject>

<body>

<footer>

Type Reference

Type	Use Case
`feat`	New feature
`fix`	Bug fix
`docs`	Documentation only
`style`	Code style (formatting, no logic change)
`refactor`	Code refactor (no feature/fix)
`perf`	Performance improvement
`test`	Add/modify tests
`ci`	CI/CD changes
`chore`	Build, deps, tooling

Rules

Subject

Max 50 characters, imperative mood, lowercase first letter, no period
Be specific: reference concrete identifiers from the diff (function names, file names, module names)
FORBIDDEN: vague subjects like "update code", "fix bug", "make changes", "minor updates"

Body

Default: NO body. Most commits need only a subject line.
Add body ONLY when:
- Multi-file changes need explanation of how they relate
- Breaking change requires migration notes
- The reason for the change is not obvious from the diff
Body explains WHY, never repeats WHAT the diff shows
Max 3 lines

Scope

Use the module or directory name as scope (e.g., auth, api, ui)
If changes span multiple modules, omit scope

Breaking Change

Add ! after type/scope: feat(api)!: restructure response format
Add BREAKING CHANGE: in footer with migration details

Examples

Subject only (most commits):

docs(guide): add Python async programming guide

With body (multi-file, needs context):

refactor(auth): extract token validation into middleware

Move validation logic from individual route handlers to shared
middleware. Reduces duplication across 5 endpoint files.

Breaking change:

feat(api)!: switch response envelope to JSON:API format

BREAKING CHANGE: response shape changed from {data, status} to {data, meta}.
Update all API clients to use new structure.