commit-msg

name	commit-msg
description	Analyze git commits and generate better commit messages based on actual changes. Use when amending commit messages, reviewing commit quality, or writing commits. Triggers on terms like "commit message", "amend commit", "fix commits", "reword commits".
user-invocable	true

Commit Message Skill

Generates and improves commit messages following conventional commits format.

Conventional Commits Format

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

[optional body]

[optional footer]

Types

Type	Use For
feat	New feature
fix	Bug fix
docs	Documentation only
style	Formatting, no code change
refactor	Code change that neither fixes a bug nor adds feature
perf	Performance improvement
test	Adding or updating tests
chore	Maintenance tasks
ci	CI/CD changes
build	Build system changes

Scopes for This Project

Scope	Description
bits	BitVec, rank/select, popcount
bp	Balanced parentheses
json	JSON semi-indexing
jq	jq query language
simd	SIMD implementations
cli	CLI tool
bench	Benchmarks
docs	Documentation

Examples

Feature Addition

feat(json): add PFSM table-driven parser

Implements parallel finite state machine approach from hw-json-simd.
Achieves 880 MiB/s throughput on x86_64 (AMD Zen 4), 40-77% faster than scalar.

Bug Fix

fix(bp): correct find_close for edge case at word boundary

Fixes #42

Performance Improvement

perf(popcount): add AVX-512 VPOPCNTDQ implementation

5.2x faster than scalar for large bitvectors.
Requires Intel Ice Lake+ or AMD Zen 4+.

Refactoring

refactor(jq): replace deprecated last() with next_back()

Removes dead code and simplifies iterator handling.

Instructions

1. Read the staged changes with git diff --cached
2. Understand what changed and why
3. Choose appropriate type and scope
4. Write a concise subject line (50 chars ideal, 72 max)
5. Add body if changes need explanation
6. Include footer for breaking changes or issue references

Commit Message Rules

1. Subject line: Imperative mood ("add" not "added")
2. No period at end of subject line
3. Blank line between subject and body
4. Body: Explain what and why, not how
5. Footer: Reference issues, note breaking changes