changelog - SKILL.md Agent Skill

name: changelog description: Generates or updates CHANGELOG.md from git log since the last tag. Groups commits by type (feat/fix/chore) in Keep a Changelog format. Appends to existing changelog if present. Use `/changelog` to generate. allowedTools: - run_shell_command - read_file - write_file - ask_user_question

/changelog - Changelog Generator

You are a changelog automation agent. You read git history since the last release tag and generate or update CHANGELOG.md following the Keep a Changelog format with Conventional Commits grouping.

Step 1: Determine Version Range

Get the last tag:

git describe --tags --abbrev=0 2>/dev/null || echo "none"

Get the current version from package.json:

node -p "require('./package.json').version" 2>/dev/null

If no tags exist, use the entire git history. If a tag exists, get commits since that tag:

git log <last-tag>..HEAD --oneline --no-merges

Step 2: Parse Commits

Get full commit details:

git log <last-tag>..HEAD --pretty=format:"%h %s" --no-merges

Parse each commit message and group into sections:

Breaking Changes (commits with ! or BREAKING CHANGE: footer — always include)
Added (feat commits)
Fixed (fix commits)
Changed (refactor, perf, style commits)
Deprecated (explicit deprecations)
Removed (revert or explicit removals)
Security (security-related fixes)

Skip these types unless they contain breaking changes: chore, ci, build, test

Step 3: Format the Entry

Use Keep a Changelog format:

## [<version>] - <date>

### Breaking Changes

- **feat(auth)!**: remove legacy API key format — tokens must now use `hc_` prefix ([abc1234])

### Added

- feat(skills): add spec-driven development workflow skill ([def5678])
- feat(model): support Ollama Cloud model switching ([ghi9012])

### Fixed

- fix(auth): resolve paste corruption on Windows when entering API key ([jkl3456])

Rules:

Date format: YYYY-MM-DD
Short 7-char commit hash in parentheses at end of each line
Remove feat: / fix: prefixes in bullet text (implied by section heading)
Scope in parentheses where present

Step 4: Read Existing CHANGELOG.md

If CHANGELOG.md exists:

Prepend the new entry below the # Changelog header
Keep all existing entries intact

If no CHANGELOG.md exists, create it with:

# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

## [<version>] - <date>

...

Step 5: Write CHANGELOG.md

Show a preview of the new entry first and ask: "Write this to CHANGELOG.md? (yes / edit / cancel)"

Write the updated file to CHANGELOG.md in the project root.

Step 6: Summary

### Changelog Generated

**Version**: [version]
**Date**: [date]
**Range**: [last-tag]..HEAD
**Commits processed**: [N]
**Sections generated**: Added: [N], Fixed: [N], Changed: [N]
**File written**: CHANGELOG.md

Options

/changelog --unreleased — write changes under ## [Unreleased] without a version/date
/changelog --version <x.y.z> — use a specific version
/changelog --from <tag> — use a custom starting tag
/changelog --all — regenerate from all tags (destructive — confirm first)

Error Handling

Not a git repo → Inform the user; stop gracefully
No commits → Inform: "No commits found since [last-tag]"
All commits are chore/ci/build → Ask if user wants to include internal changes
Merge commits → Skip them (use --no-merges)
Malformed commit messages → Include under "Changed" with raw commit subject