Git Commit Helper Skill

Generate conventional commit messages from your git diff.

When I Activate

✅ git commit without message
✅ User asks "what should my commit message be?"
✅ Staged changes exist
✅ User mentions commit or conventional commits
✅ Before creating commits

What I Generate

Conventional Commit Format

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

<body>

<footer>

Types:

feat: New feature
fix: Bug fix
docs: Documentation changes
style: Code style (formatting, no logic change)
refactor: Code refactoring
perf: Performance improvements
test: Test additions or fixes
build: Build system changes
ci: CI/CD changes
chore: Maintenance tasks

Examples

Feature Addition

# You staged:
git add auth.service.ts login.component.tsx

# I analyze diff and suggest:
feat(auth): add JWT-based user authentication

- Implement login/logout functionality
- Add token management service
- Include auth guards for protected routes
- Add unit tests for auth service

Closes #42

Bug Fix

# You staged:
git add UserList.tsx

# I suggest:
fix(components): resolve memory leak in UserList

Fixed subscription not being cleaned up in useEffect,
causing memory leak when component unmounts.

Closes #156

Breaking Change

# You staged:
git add api/users.ts

# I suggest:
feat(api): update user API response format

Changed response structure to include metadata
for better pagination and filtering support.

BREAKING CHANGE: User API now returns { data, metadata }
instead of direct array. Update client code accordingly.

Documentation Update

# You staged:
git add README.md docs/api.md

# I suggest:
docs: update API documentation with authentication examples

- Add authentication flow diagrams
- Include cURL examples for protected endpoints
- Document error responses

Analysis Process

Step 1: Check Staged Changes

git diff --staged --name-only
git diff --staged

Step 2: Categorize Changes

New files → feat
Modified files → fix, refactor, or feat
Deleted files → chore or refactor
Test files → test
Documentation → docs

Step 3: Analyze Content

What was changed?
Why was it changed?
What's the impact?
Are there breaking changes?

Step 4: Generate Message

Subject line:

Max 50 characters
Imperative mood ("add" not "added")
No period at end
Lowercase after type

Body:

Explain WHAT and WHY, not HOW
Wrap at 72 characters
Bullet points for multiple changes

Footer:

Breaking changes: BREAKING CHANGE: description
Issue references: Closes #123, Fixes #456

Message Components

Type Selection

feat: New functionality
  - New components, features, capabilities

fix: Bug fixes
  - Resolving issues, fixing bugs

refactor: Code improvements
  - No functional changes, better code structure

perf: Performance
  - Speed improvements, optimization

docs: Documentation
  - README, comments, guides

test: Testing
  - Adding or fixing tests

style: Formatting
  - Code style, linting, formatting

chore: Maintenance
  - Dependencies, build config, tooling

Scope Selection

Common scopes:

Component name: feat(UserCard): ...
Module: fix(auth): ...
Package: chore(api): ...
Area: docs(readme): ...

Subject Guidelines

✅ Good:

add user authentication
fix memory leak in component
update API documentation

❌ Bad:

added user authentication (past tense)
fixes bug (too vague)
Update API docs. (period at end)

Advanced Examples

Multiple Changes

# Multiple files in auth feature
feat(auth): implement complete authentication system

- Add JWT token generation and validation
- Implement password hashing with bcrypt
- Create login/logout API endpoints
- Add auth middleware for protected routes
- Include refresh token functionality

Closes #42, #43, #44

Refactoring

# Code restructuring
refactor(api): extract database logic into repository pattern

Moved database queries from controllers to repository classes
for better separation of concerns and testability.

No functional changes or API modifications.

Performance Improvement

# Optimization
perf(queries): optimize user data fetching

- Implement query batching to eliminate N+1 queries
- Add database indices on frequently queried columns
- Cache user profile data with 5-minute TTL

Performance improvement: 80ms → 12ms average response time

Git Integration

Pre-commit Hook

I work great with pre-commit hooks:

#!/bin/sh
# .git/hooks/prepare-commit-msg

# If no commit message provided, trigger skill
if [ -z "$2" ]; then
  # Skill suggests message based on staged changes
  echo "# Suggested commit message (edit as needed)" > "$1"
fi

Amending Commits

# Poor initial message
git commit -m "fix stuff"

# Amend with better message
# I suggest improved message based on changes
git commit --amend

Sandboxing Compatibility

Works without sandboxing: ✅ Yes Works with sandboxing: ✅ Yes

May need network access for:

Fetching issue details from GitHub API
Checking if issue numbers are valid

Sandbox config (optional):

{
  "network": {
    "allowedDomains": [
      "api.github.com"
    ]
  }
}

Customization

Custom Commit Types

Edit SKILL.md to add company-specific types:

deploy: Deployment
migrate: Database migrations
hotfix: Production hotfixes

Custom Scopes

Train the skill to recognize your project structure:

Common scopes: auth, api, ui, database, admin, mobile

Message Templates

Customize message format for your team:

# Standard format
feat(scope): subject

# Your custom format
[JIRA-123] feat(scope): subject

Tips for Best Messages

Be specific: "fix login button" not "fix bug"
Use imperative mood: "add" not "added" or "adds"
Include context: Why this change was needed
Reference issues: Always include issue numbers
Breaking changes: Always flag in footer

Common Patterns

Frontend Changes

feat(ui): add responsive navigation menu
fix(components): resolve prop validation warning
style(css): update button hover effects

Backend Changes

feat(api): add user pagination endpoint
fix(database): resolve connection pool exhaustion
perf(queries): add database indices for user lookups

Infrastructure Changes

ci: add automated deployment pipeline
build: update dependencies to latest versions
chore(docker): optimize container image size

Related Tools

code-reviewer skill: Reviews code before commit
@docs-writer sub-agent: Generates changelog from commits
/review command: Pre-commit code review

Integration

With code-reviewer

# 1. Write code
# 2. code-reviewer flags issues
# 3. Fix issues
# 4. Stage changes
# 5. I generate commit message
git commit  # Uses my suggested message

With /review Command

# 1. Make changes
/review --scope staged  # Review before commit
# 2. Address findings
# 3. Stage final changes
# 4. I generate commit message
git commit

git-commit-helper