Changelog Generation

Changelog Generation Skill

Skill: changelog-generation Created: 2026-01-09 Agent: documenter Category: Documentation

Purpose

Generate CHANGELOG.md entries following the Keep a Changelog format. Creates clear, user-facing descriptions of changes organized by version and change type.

When to Activate

Trigger Conditions:

• After story completion and feature merge
• Before release/deployment
• When documenter agent needs to document changes
• After bug fixes or feature updates

Activation Pattern:

When: Story marked complete AND code merged
Then: Generate changelog entry for version

Core Capabilities

1. Change Classification

• Automatically categorize changes into:
  • Added - New features
  • Changed - Changes to existing functionality
  • Deprecated - Soon-to-be removed features
  • Removed - Removed features
  • Fixed - Bug fixes
  • Security - Security vulnerability fixes

2. Version Management

• Follow Semantic Versioning (MAJOR.MINOR.PATCH)
• Link versions to release dates
• Maintain chronological order (newest first)
• Support unreleased changes section

3. Entry Generation

• Convert technical commits to user-facing language
• Link to issue/PR numbers
• Highlight breaking changes
• Group related changes together

[TECH_STACK_SPECIFIC] Sections

Ruby on Rails Projects

## Integration Points
- Parse git commit history: `git log --pretty=format:"%s"`
- Extract version from: `config/version.rb` or Git tags
- Link to PRs via GitHub API
- Reference issues from commit messages

## Rails-Specific Categories
- **Migration** - Database schema changes
- **Dependency** - Gem updates
- **Performance** - Query optimizations, caching

Node.js Projects

## Integration Points
- Parse git commit history
- Extract version from: `package.json`
- Link to PRs via GitHub API
- Follow Conventional Commits format

## Node-Specific Categories
- **Dependency** - npm package updates
- **Build** - Build tool or pipeline changes
- **CI/CD** - Continuous integration updates

API Projects

## Integration Points
- Track API version changes
- Document endpoint modifications
- Note breaking API changes
- Reference API specification updates

## API-Specific Categories
- **Endpoint** - New or modified endpoints
- **Breaking** - Breaking API changes
- **Response** - Response format changes

Tools Required

Primary Tools

• nn__documentation-generator - Format changelog entries

MCP Servers

[MCP_TOOLS]

Quality Checklist

Before Generating:

• All changes since last version identified
• Git tags verified for version numbers
• PRs/issues linked correctly
• Breaking changes flagged

Entry Quality:

• User-facing language (no technical jargon)
• Changes categorized correctly
• Chronological order maintained
• Date format: YYYY-MM-DD
• Links functional (PRs, issues, commits)
• Breaking changes prominently noted

Format Compliance:

• Follows Keep a Changelog format
• Semantic versioning used
• Unreleased section present (if applicable)
• Comparison links included

Documentation Examples

Complete Changelog Structure

# 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/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [Unreleased]

### Added
- User profile avatar upload functionality
- Email notification preferences

### Changed
- Improved dashboard loading performance

## [1.2.0] - 2026-01-09

### Added
- OAuth2 authentication support (#123)
- Two-factor authentication via SMS (#145)
- Password strength indicator on signup

### Changed
- Updated user session timeout to 24 hours (#156)
- Improved error messages for login failures

### Fixed
- Fixed password reset email not sending (#178)
- Resolved session persistence issue on mobile browsers (#182)

### Security
- Patched XSS vulnerability in user comments (#190)

## [1.1.0] - 2025-12-15

### Added
- User dashboard with activity timeline
- Export user data to CSV

### Deprecated
- Legacy API v1 endpoints (will be removed in 2.0.0)

## [1.0.0] - 2025-11-01

### Added
- Initial release
- User registration and authentication
- Profile management
- Basic dashboard

[Unreleased]: https://github.com/user/repo/compare/v1.2.0...HEAD
[1.2.0]: https://github.com/user/repo/compare/v1.1.0...v1.2.0
[1.1.0]: https://github.com/user/repo/compare/v1.0.0...v1.1.0
[1.0.0]: https://github.com/user/repo/releases/tag/v1.0.0

Single Version Entry

## [2.0.0] - 2026-01-15

### Added
- **BREAKING**: New API v2 with GraphQL support (#200)
- Real-time notifications via WebSocket (#210)
- Multi-language support (EN, DE, FR, ES) (#215)

### Changed
- **BREAKING**: User authentication now requires email verification (#220)
- Redesigned dashboard UI with improved navigation (#225)
- Database query optimization reducing load times by 40% (#230)

### Deprecated
- REST API v1 endpoints (use GraphQL API v2)
- Legacy user session format

### Removed
- **BREAKING**: Removed deprecated `/api/v0` endpoints
- Legacy CSV export format

### Fixed
- Fixed memory leak in background job processor (#245)
- Resolved timezone display issue in activity logs (#250)
- Fixed duplicate notification bug (#255)

### Security
- Updated Rails to 8.0.1 for security patches
- Implemented rate limiting on API endpoints (#260)
- Enhanced password encryption algorithm (#265)

Migration Note Example

## [2.0.0] - 2026-01-15

### Migration Notes

**Breaking Changes:**
This release includes breaking changes. Please review before upgrading.

1. **API v2 Migration**: All API clients must migrate to GraphQL endpoints
   - Old: `GET /api/v1/users/:id`
   - New: GraphQL query `user(id: $id)`
   - See migration guide: docs/api-v2-migration.md

2. **Email Verification Required**: Existing users must verify emails
   - Run migration: `rails db:migrate`
   - Send verification emails: `rails users:send_verification`

3. **Session Format Change**: Users will be logged out on upgrade
   - No action required
   - Users must log in again after deployment

Format Guidelines

Keep a Changelog Standards

Version Headers:

## [VERSION] - YYYY-MM-DD

Category Order:

1. Added
2. Changed
3. Deprecated
4. Removed
5. Fixed
6. Security

Entry Format:

- Brief description of change (#PR-number)
- Another change with @username credit (#PR-number)

Breaking Changes:

- **BREAKING**: Description of breaking change (#PR-number)

Comparison Links:

[VERSION]: https://github.com/user/repo/compare/vPREV...vCURRENT

Writing Style

DO:

• Use present tense: "Add feature" not "Added feature"
• Start with verb: "Add", "Fix", "Update", "Remove"
• Be specific: "Fix login timeout issue" not "Fix bug"
• Include PR/issue numbers: (#123)
• Credit contributors when appropriate: @username
• Highlight breaking changes: BREAKING

DON'T:

• Use technical jargon: "Refactored UserService" → "Improved user management performance"
• Include commit hashes in entries (use PR numbers)
• Add developer-only changes (unless significant)
• Duplicate entries across categories

Version Numbering

Semantic Versioning:

• MAJOR (1.0.0 → 2.0.0): Breaking changes
• MINOR (1.0.0 → 1.1.0): New features, backwards compatible
• PATCH (1.0.0 → 1.0.1): Bug fixes, backwards compatible

Pre-release:

• Alpha: 1.0.0-alpha.1
• Beta: 1.0.0-beta.1
• RC: 1.0.0-rc.1

Integration Examples

From Git Commits

# Extract commits since last tag
git log v1.1.0..HEAD --pretty=format:"%s"

# Convert to changelog entries
feat: Add OAuth2 support (#123)        → Added - OAuth2 authentication support (#123)
fix: Resolve login timeout (#178)      → Fixed - Fixed login timeout issue (#178)
chore: Update dependencies             → [Skip - internal change]

From GitHub PRs

{
  "pr_number": 123,
  "title": "Add OAuth2 authentication support",
  "labels": ["feature", "authentication"],
  "merged_at": "2026-01-09"
}

Converts to:

### Added
- OAuth2 authentication support (#123)

From Jira Issues

PROJ-456: Implement two-factor authentication
Type: Story
Status: Done

Converts to:

### Added
- Two-factor authentication via SMS (PROJ-456)

Automation Workflow

1. Story Completed
   ↓
2. Extract Changes
   - Git commits since last release
   - Merged PRs
   - Closed issues
   ↓
3. Categorize Changes
   - Parse commit messages
   - Analyze PR labels
   - Group related changes
   ↓
4. Generate Entry
   - Format according to Keep a Changelog
   - Add to [Unreleased] section
   - Link PRs and issues
   ↓
5. Review & Update
   - Verify categorization
   - Improve descriptions
   - Flag breaking changes
   ↓
6. On Release
   - Move [Unreleased] to [VERSION]
   - Add release date
   - Create comparison link

Best Practices

1. Update Continuously: Add to [Unreleased] as changes merge
2. User Perspective: Write for end users, not developers
3. Be Specific: "Fix login timeout" not "Fix issue"
4. Link Everything: PRs, issues, commits, contributors
5. Flag Breaking Changes: Use BREAKING prefix prominently
6. Group Related: Combine related changes into single entry
7. Provide Context: Add migration notes for major changes
8. Maintain History: Never delete old entries, only add new ones

Remember: The changelog is for users to understand what changed and why it matters to them. Focus on impact, not implementation.