git-commit-guardian - SKILL.md Agent Skill

name: git-commit-guardian description: Enforces Conventional Commits format, validates message quality (72 char subject, 80 char body), and BLOCKS AI attribution pollution. Use when committing changes, creating commit messages, or reviewing commit message quality. Make sure to use this skill whenever a git commit is being created — it prevents AI attribution trailers and enforces the project's strict Conventional Commits format. allowed-tools: Read, Bash, Grep, Glob

Git Commit Guardian

Enforces professional commit standards and prevents AI attribution pollution.

Instructions

1. Intercept Commit Intent

Detect: "commit", "git commit", "commit changes", "push this", "done, commit it". Activate immediately before any commit action.

2. Analyze Staged Changes

git diff --cached --name-only
git diff --cached

# Check for sensitive files (BLOCK if found)
git diff --cached --name-only | grep -E '\.(env|pem|key|credentials)$'

Determine commit type from changes:

feat — New feature files
fix — Bug fixes
docs — Only docs/comments
refactor — Restructure, same behavior
test — Test additions/fixes
build — Build system, dependencies
chore — Maintenance

Fakt-specific scopes: compiler, fir, ir, generation, analysis, dsl, gradle, annotations, samples

3. Validate Commit Message

Required format:

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

[optional body]

[optional footer]

Validation rules:

Valid type: feat|fix|docs|style|refactor|perf|test|build|ci|chore|revert
Subject ≤72 characters
No trailing period
Imperative mood ("add" not "added")
Blank line between subject and body
Body lines wrapped at 80 characters

4. BLOCK Forbidden Patterns (CRITICAL)

These MUST NEVER appear in commits:

FORBIDDEN — ALWAYS BLOCK:

1. "Generated with [Claude Code]" / "Generated with Claude Code" / "Generated by Claude"
2. "Co-Authored-By: Claude" / "Co-authored-by:.*Claude" / "Co-authored-by:.*Anthropic"
3. "Co-Authored-By:.*noreply@anthropic.com"
4. Robot emoji + "Generated"

If detected:

COMMIT BLOCKED — AI Attribution Detected

Found: "Co-Authored-By: Claude <noreply@anthropic.com>"
This project requires clean commits without AI attribution.
Remove the offending line and retry.

NON-NEGOTIABLE. Always strip before committing.

5. Execute Commit

Only after all validations pass:

git commit -m "$(cat <<'EOF'
<validated commit message>
EOF
)"

Verify:

git log -1 --format="%H %s"

6. Handle Edge Cases

Multiple logical changes — recommend splitting:

1. refactor(types): extract TypeResolver to separate file
2. feat(types): add variance handling
3. test(types): add unit tests for TypeResolver

Error Messages

Invalid Type:

COMMIT BLOCKED — Invalid Type
"update" is not valid. Use: feat, fix, docs, style, refactor, perf, test, build, ci, chore, revert

Subject Too Long:

COMMIT BLOCKED — Subject exceeds 72 characters (currently: {n})
Suggested: "{shortened version}"

Supporting Files

resources/conventional-commits-reference.md — Full spec
resources/commit-message-patterns.md — Project-specific examples

Related Skills

bdd-test-runner — Run tests before committing
compilation — Validate code compiles before committing