---
name: git-commit-writer
description: >-
  Write, review, or amend Git commit messages using Erning's conventions.
  Use for commit requests and message drafting or validation. Require English
  ASCII Conventional Commits with a scope and a useful body. History inspection
  and general Git questions alone do not trigger this skill.
---

# Git Commit Message Conventions

Apply this skill only to the commit message. Do not add repository inspection,
diff review, staging, permission, or commit-execution steps solely because
this skill is active; follow the surrounding task instructions for those
operations. A request to draft or review a message does not authorize creating
a commit.

Write commit messages in English ASCII. This requirement applies only to the
commit message, not to explanations or conversation with the user.

## Format and content

Use `type(scope): description`, for example:

```text
docs(readme): clarify installation steps

Separate local and global installation examples to make the target location
explicit.
```

- Use one of `build`, `chore`, `ci`, `docs`, `feat`, `fix`, `perf`,
  `refactor`, `revert`, `style`, or `test`.
- Require a non-empty scope starting with a lowercase ASCII letter or digit.
  Remaining characters may only be lowercase ASCII letters, digits, `.`, `_`,
  or `-`.
- Add `!` before `:` only for a breaking change.
- Write a concise imperative description starting with a lowercase ASCII
  letter and do not end the subject with a period.
- Separate the subject and body with exactly one blank line. Always include a
  useful body that explains the reason, effect, or important implementation
  detail without merely repeating the subject.
- Keep subject and body lines at 78 characters or fewer when possible and
  never exceed 80 characters. Do not leave trailing whitespace.
- Describe only facts supported by the changes. Do not invent issue numbers,
  context, or validation results.
- Do not add authorship, coauthor, AI-generation, tool, model, vendor, or
  equivalent attribution, such as `Co-authored-by:`, `Signed-off-by:`, or
  `Generated by ChatGPT.`. Tool and vendor names, models, and fields such as
  `generated-by` may appear when they describe the actual changes.

## Validation

Run the bundled `scripts/validate_commit_message.py` only when the user
explicitly asks to validate a proposed message. Do not run it for ordinary
commit requests. From this skill's directory, run
`python3 scripts/validate_commit_message.py <message-file>`, or use `-` as the
file argument to read from standard input.

The script checks ASCII, subject format, line length, blank-line separation,
body presence, and common attribution forms. Passing these mechanical checks
does not establish an imperative tone, factual accuracy, a useful body, or the
absence of other attribution wording; review those in context.