commit

name	commit
description	Git commit message conventions and pre-commit guidance. Use when committing code.

Commit

This skill covers commit message conventions and pre-commit checks. A diff shows what changed, but only the commit message can explain why. Well-crafted commit messages communicate context to fellow developers and your future self.

Before committing

Branch sanity check

Before staging, verify the current branch is appropriate for this change:

1. Run git status and git log --oneline -5.
2. If the branch tracks a remote and is up-to-date (i.e., "up to date with 'origin/...'"), prior work has been pushed. Ask the user whether this is a continuation or whether a new branch is needed.
3. If the branch name doesn't relate to the commit subject, flag the mismatch. Example: branch fix-auth-flow, commit about adding a new feature.
4. If on main/master and the change is non-trivial, suggest creating a feature branch first.

If any check flags, present the concern and offer to create a new branch. Do not refuse to commit — the user may have a valid reason to stay on the current branch.

Review

For non-trivial changes (multiple files, new features, refactors), run the review skill first. For small, obvious changes (typos, single-line fixes), use your judgment — a full review pass may be overkill.

When to Use

Use this skill when:

• Committing code changes
• Writing commit messages
• Reviewing commits for style compliance

Style

We follow the Imperative Commit Style inspired by Git/Linux kernels, NOT standard Conventional Commits.

Granularity & Atomicity

• Keep commits brief and atomic (e.g., don't mix refactors with new features)
• Commit early and often. Multiple smaller commits help with reviews and rebasing
• Don't split a single logical change into several commits (e.g., feature implementation and tests should be in the same commit)

Commit Message Format

Subject Line

• Capitalize the subject line
• Start with an active verb in the imperative present tense (e.g., Add, Change, Fix, Remove)
• Do not use type prefixes (e.g., feat:, fix:, chore:)
• Do not end the subject line with punctuation
• Keep lines under 50 characters, if possible

Body

• Adding further description is encouraged, but should be avoided when trivial
• Use the body to explain what and why, not how
  • Focus on the reasons for the change
  • Explain the problem being solved
  • Note any side effects or unintuitive consequences
  • The code itself explains how

Examples

Good:

Add user authentication to the portal

This implements JWT-based authentication with refresh tokens.
The session timeout is set to 24 hours.

Good (simple change):

Fix typo in login error message

Bad (uses type prefix):

feat: add user authentication

Bad (not imperative):

Added user authentication

Quality Standards

• Each commit merged to master/main must pass the testing suite
• Never push dead code. If you need it later, you can use git to bring it back.

Squashing & Fixups

If a commit is going to be squashed to another commit, use the --squash and --fixup flags respectively to make the intention clear.