git-commit-message

Git Commit + Message Skill

Create a well-structured commit message and, with user approval, run git commit using that message.

When to Activate This Skill

Trigger this skill for any request to write a commit message and/or commit code, including:

• "write well formatted git commit message"
• "commit with this message" / "commit using this message"
• "commit these changes" / "commit now" / "commit the staged files"
• "create a commit message" / "generate a commit message"
• "save to git" / "check in" / "git commit" / "commit and push"
• "review my commit message" / "is this a good commit message"

Commit Message Structure

A commit message has three parts: header (required), body (optional), and footer (optional).

Header (Subject Line)

1. Use imperative mood (e.g., "Add", "Fix", "Update", not "Added", "Fixed", "Updated")
2. Start with a capital letter
3. Do not end with a period
4. Limit to 50 characters maximum
5. Complete the sentence: "If applied, this commit will..."

Body

1. Separate from header with a blank line
2. Wrap lines at 72 characters
3. Explain what changed and why (not how)
4. Include relevant context, background, or reasoning

Footer

1. Reference issues: Closes #123, Fixes #456, See also: #789
2. Note breaking changes: BREAKING CHANGE: description
3. Add co-authors: Co-authored-by: name <email@example.com>

Steps to Create and Apply a Commit

Follow this workflow when asked to write a commit message and/or commit the changes:

1. Check staged changes

   • Run git diff --cached to see staged changes.
   • If empty: tell the user nothing is staged and suggest git add <files>.

2. Analyze the diff

   • Purpose: feature, fix, docs, refactor, etc.
   • Scope: module/area touched.
   • Impact: any breaking change?
   • Issues: any referenced tickets?

3. Pick the commit type (Conventional Commits)

   • feat, fix, refactor, docs, style, test, chore, perf, ci, revert

4. Draft the commit message

   • Header: <type>(<scope>): <description> (≤50 chars)
   • Body (optional): what + why, wrapped at 72 chars
   • Footer (optional): issue refs, breaking change notice, co-authors

5. Show the message to the user for approval

6. Commit when approved

   • Single-line: git commit -m "header" (and add -m "body" -m "footer" if present)
   • Or open editor: git commit

7. Confirm success

   • Show latest commit: git log -1 --pretty=format:"%h - %s"

Format and Examples

Message Structure

<type>(<scope>): <description>

[optional body explaining what and why, not how]

[optional footer with issue refs, breaking changes, or co-authors]

Key Rules:

• Imperative mood: Use "Add", "Fix", "Update" (not "Added", "Fixed", "Updated")
• Capital first letter: Start with uppercase
• No period: Don't end header with a period
• 50 char header max: Keep subject line concise
• 72 char body wrap: Wrap body text for terminal readability
• Blank line separation: Separate header from body and body from footer
• Explain why: Focus on motivation and implications, not code mechanics
• Be specific: Mention the component or module affected
• No vague messages: Avoid "Fix stuff", "Update", "Changes" without context
• No meta-commentary: Don't say "this commit" or "in this PR"
• No personal pronouns: Avoid "I fixed" – use imperative instead
• Ready to apply: Ensure the message is final before running git commit

Example Commits

Simple fix (feature or bug):

fix(auth): handle null pointer in user login flow

Feature with body:

feat(oauth): add OAuth 2.0 authentication support

Implement OAuth 2.0 login using the external provider library.
This introduces a new callback endpoint and updates the user
model with OAuth tokens for secure authentication.

Closes #42

Breaking change:

refactor(api)!: standardize response format

Standardize all API endpoints to return responses in a unified
JSON structure with status, data, and error fields.

BREAKING CHANGE: API responses now use a new envelope format.
Clients must update their parsing logic.

Closes #128

With co-author:

perf(cache): improve user profile API caching

Reduce database queries by implementing Redis caching for
frequently accessed user profile data. This improves response
times by approximately 40%.

Co-authored-by: Jane Doe <jane@users.noreply.github.com>

Documentation update:

docs(readme): update installation instructions

Add steps for Docker-based setup and troubleshooting section
for common installation issues on Windows.

Test addition:

test(api): add integration tests for auth endpoints

Cover happy path, invalid credentials, and rate limiting
scenarios for login and registration endpoints.

Quality Standards

Every commit message must follow these rules:

• One logical change per commit – keep commits focused and atomic
• Describe impact, not mechanics – explain what changed and why, not the code mechanics
• Complete the sentence – your header should complete: "If applied, this commit will..."
• Include scope when possible – fix(module) is clearer than just fix
• Reference related issues – use Closes #123, Fixes #456, Related to #789
• Flag breaking changes – use ! in header or BREAKING CHANGE: in footer
• Provide context – body text should explain the why and what, not the how
• Use past-tense body – describe what was done in past tense in the body
• No abbreviations – spell out terms clearly for future readers
• Keep it focused – if the message is hard to write concisely, the change may be too broad

Workflow and Common Scenarios

Scenario 1: "write well formatted git commit message"

1. Check git diff --cached.
2. Draft the message (type/scope/description, optional body/footer).
3. Show the message for approval.
4. On approval, run git commit -m ... and confirm.

Scenario 2: "commit with this message "

1. Validate the provided message against the format (type(scope): description).
2. Suggest any fixes (imperative, ≤50 chars header, etc.).
3. On approval, run git commit -m ... and confirm.

Scenario 3: "commit these changes" / "commit now"

1. Check staged changes. If none, ask user to stage.
2. Draft the message following the steps.
3. Show for approval, then commit and confirm.

Scenario 4: No staged changes

1. Run git status.
2. Inform: "No staged changes to commit."
3. Suggest: git add <files> then continue.

Scenario 5: Multiple unrelated changes

1. Note that changes span different areas.
2. Offer: split into separate commits (X, Y) with separate messages.
3. Proceed per user choice.