Commit Message Generator
Generate conventional commit messages from staged git changes.
Overview
This skill automates commit message generation for development teams. It analyzes staged changes, detects the appropriate commit type (feat, fix, refactor, etc.), suggests a scope based on modified files, and generates a properly formatted message following the Conventional Commits specification.
What it automates:
- Analysis of staged git changes
- Commit type detection based on change patterns
- Scope suggestion from file paths
- Message formatting with subject/body/footer
Time saved: ~2-5 minutes per commit
Triggers
Run this skill when:
- You have staged changes ready to commit
- You want a well-formatted conventional commit
- You need to reference issues or breaking changes
Workflow
Step 1: Analyze Staged Changes
First, I'll examine what's staged:
git diff --cached --stat
git diff --cached --name-status
This shows:
- Files added (A), modified (M), deleted (D), renamed (R)
- Lines changed per file
- Overall change scope
Step 2: Detect Commit Type
Based on the changes, I'll determine the appropriate type:
| Pattern | Type | Description |
|---|---|---|
| New feature files | feat | New functionality |
| Bug fix in existing code | fix | Bug repair |
| Code restructuring | refactor | No behavior change |
| Performance improvements | perf | Faster/leaner code |
| Test additions/changes | test | Test updates |
| Documentation only | docs | Documentation |
| Formatting/style | style | No code change |
| Build/CI config | build/ci | Infrastructure |
| Maintenance | chore | Other changes |
Step 3: Suggest Scope
Extract scope from the primary changed directory:
src/api/*→ scope:apisrc/components/*→ scope:componentslib/utils/*→ scope:utils- Multiple areas → omit scope or use parent
Step 4: Generate Message
Format following Conventional Commits:
<type>(<scope>): <description>
<body - explains why, not how>
<footer - issues, breaking changes>
Subject line rules:
- Maximum 50 characters
- Imperative mood ("Add" not "Added")
- No period at end
- Capitalize first letter
Step 5: Review and Commit
Present the generated message for your approval, then execute:
git commit -m "<message>"
Verification
Success Indicators
- Commit type matches the nature of changes
- Subject line is under 50 characters
- Message uses imperative mood
- Breaking changes are properly noted
- Issue references are included when applicable
Message Validation
Before committing, I verify:
- Type is valid (feat, fix, docs, etc.)
- Subject line <= 50 characters
- Imperative mood used
- No trailing period
- Body wrapped at 72 characters (if present)
- Footer format correct (if present)
Examples
Example 1: Simple Feature
User: Generate a commit message for my staged changes
Assistant: Analyzing staged changes...
git diff --cached --name-status:
A src/components/Button.tsx
M src/components/index.ts
Detected: New component file added
Type: feat
Scope: components
Generated message:
feat(components): add Button component
Proceed with this commit? (y/n)
Example 2: Bug Fix with Issue Reference
User: /commit - this fixes issue #42
Assistant: Analyzing staged changes...
git diff --cached --name-status:
M src/utils/parser.ts
Detected: Modified existing utility code
Type: fix
Scope: utils
Generated message:
fix(utils): resolve array parsing edge case
Handle empty arrays correctly in parser to prevent
undefined errors when processing user input.
Closes #42
Proceed with this commit? (y/n)
Example 3: Breaking Change
User: Generate commit - this changes the API signature
Assistant: Analyzing staged changes...
git diff --cached --name-status:
M src/api/auth.ts
M src/types/auth.ts
Detected: API modification with signature change
Type: feat (with breaking change)
Scope: api
Generated message:
feat(api)!: update authentication flow
Migrate from session-based to JWT authentication.
This changes the login endpoint response format.
BREAKING CHANGE: login() now returns {token, refreshToken}
instead of {sessionId}. All clients must update their
authentication handling.
Proceed with this commit? (y/n)
Configuration
Commit Types Reference
| Type | When to Use | SemVer Impact |
|---|---|---|
feat | New feature | Minor bump |
fix | Bug fix | Patch bump |
docs | Documentation only | None |
style | Formatting, no code change | None |
refactor | Code restructure, no behavior change | None |
perf | Performance improvement | None |
test | Adding/updating tests | None |
build | Build system changes | None |
ci | CI configuration | None |
chore | Maintenance tasks | None |
Breaking Changes
Add ! after type/scope or include footer:
feat!: change APIfeat(api)!: update endpoint- Footer:
BREAKING CHANGE: description
Output Checklist
Before finalizing a commit message:
- Type accurately reflects the change
- Scope matches the affected area
- Subject is imperative mood
- Subject <= 50 characters
- Body explains why (if included)
- Body wrapped at 72 characters
- Breaking changes documented
- Issue references included