Changelog Format

Keep a Changelog Format

This skill provides guidelines for writing and formatting changelogs following the Keep a Changelog specification.

Core Principles

1. Changelogs are for humans - Write for users, not machines
2. Every version gets a section - Including [Unreleased] for upcoming changes
3. Changes are grouped by type - Consistent categorization
4. Versions are linkable - Each version header links to comparison
5. Latest version comes first - Reverse chronological order
6. Release dates are shown - ISO format: YYYY-MM-DD

Change Categories

Use these categories in this order:

Category Guidelines

Added

• New user-facing features
• New API endpoints
• New configuration options
• New integrations

Changed

• Performance improvements
• UX/UI changes
• Default value changes
• Behavior modifications

Deprecated

• Features planned for removal
• APIs being replaced
• Include migration path when possible

Removed

• Breaking changes (removed functionality)
• Deleted APIs or features
• Always note what replaced it (if applicable)

Fixed

• Bug corrections
• Error handling improvements
• Edge case fixes

Security

• Vulnerability patches
• Security-related fixes
• Always include CVE if available

Entry Writing Guidelines

Use Imperative Mood

Start entries with imperative verbs:

Focus on User Impact

Write from the user's perspective:

Be Specific and Concise

Include Context When Helpful

Use parenthetical context for clarity:

- Add OAuth2 support (Google, GitHub)
- Fix timezone handling (UTC offset calculation)
- Change rate limit (100 -> 500 requests/minute)

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/),
and this project adheres to [Semantic Versioning](https://semver.org/).

## [Unreleased]

### Added
- New entries go here

## [1.0.0] - 2024-01-15

### Added
- Initial public release
- Feature A with description
- Feature B with description

### Changed
- Improvement to existing feature

### Fixed
- Bug fix description

## [0.9.0] - 2024-01-01

### Added
- Beta release features

[Unreleased]: https://github.com/owner/repo/compare/v1.0.0...HEAD
[1.0.0]: https://github.com/owner/repo/compare/v0.9.0...v1.0.0
[0.9.0]: https://github.com/owner/repo/releases/tag/v0.9.0

Semantic Versioning Connection

Changelog categories map to version bumps:

What NOT to Include

• Internal refactoring (unless it affects users)
• Dependency updates (unless they affect functionality)
• Test changes
• CI/CD changes
• Documentation-only changes (unless user-facing docs)
• Code style/formatting changes

Changelog Entry Examples

This section provides examples of well-written and poorly-written changelog entries to guide entry creation.

Added Category

Good Examples

- Add user authentication with email/password and OAuth (Google, GitHub)
- Add bulk export of transactions to CSV and Excel formats
- Add keyboard shortcuts for common actions (Ctrl+S to save, Ctrl+Z to undo)
- Add dark mode with automatic system preference detection
- Add webhook support for order status changes
- Add rate limiting (100 requests/minute per API key)

Poor Examples (with corrections)

Changed Category

Good Examples

- Improve search performance (3x faster for large datasets)
- Change default session timeout from 30 minutes to 2 hours
- Update password requirements: minimum 12 characters, 1 number required
- Redesign settings page with tabbed navigation
- Move API documentation to /docs endpoint
- Increase file upload limit from 5MB to 25MB

Poor Examples (with corrections)

Fixed Category

Good Examples

- Fix crash when uploading files larger than 10MB
- Fix incorrect tax calculation for international orders
- Fix login button not responding on mobile Safari
- Fix timezone display showing UTC instead of local time
- Fix memory leak causing slowdown after extended use
- Fix email notifications not sending for new comments

Poor Examples (with corrections)

Removed Category

Good Examples

- Remove deprecated /api/v1 endpoints (use /api/v2 instead)
- Remove support for Internet Explorer 11
- Remove "Classic" theme (migrate to "Modern" theme in settings)
- Remove automatic social media sharing (use manual share buttons)
- Remove legacy import format (use CSV import instead)

Poor Examples (with corrections)

Deprecated Category

Good Examples

- Deprecate /api/v1/users endpoint (use /api/v2/users, removal in v3.0)
- Deprecate XML export format (use JSON export, removal in 6 months)
- Deprecate "Classic" theme (will be removed in next major version)
- Deprecate basicAuth parameter (use apiKey authentication instead)

Poor Examples (with corrections)

Security Category

Good Examples

- Fix XSS vulnerability in comment rendering (CVE-2024-1234)
- Fix SQL injection in search query parameter
- Add Content-Security-Policy headers
- Update authentication to prevent session fixation attacks
- Fix CSRF vulnerability in account settings form
- Upgrade TLS minimum version to 1.2

Poor Examples (with corrections)

Grouping Related Changes

When multiple related changes are made, group them thoughtfully:

Good Grouping

### Added
- Add user profile customization
  - Profile picture upload
  - Bio and social links
  - Custom theme colors
- Add team collaboration features
  - Shared workspaces
  - Real-time presence indicators
  - Comment threads on items

Alternative: Separate Entries

### Added
- Add profile picture upload with crop and resize
- Add customizable bio and social media links
- Add shared team workspaces
- Add real-time presence indicators for team members

Entries with Technical Context

When technical details help users, include them appropriately:

Good Examples

- Add GraphQL API alongside existing REST API
- Add WebSocket support for real-time updates (replaces polling)
- Fix N+1 query issue causing slow dashboard load
- Change database connection pooling (improves concurrent user handling)

Avoid Over-Technical Entries

Breaking Changes

Clearly indicate breaking changes:

### Removed
- **BREAKING**: Remove support for Node.js 14 (minimum now Node.js 18)
- **BREAKING**: Remove /api/v1 endpoints (migrate to /api/v2)

### Changed
- **BREAKING**: Change config file format from YAML to TOML
- **BREAKING**: Rename `user.name` field to `user.displayName` in API responses