The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

Added

New user profile customization options
Dark mode support

Changed

Improved performance of search feature

Fixed

Bug in password reset email

1.2.0 - 2025-01-15

Added

Two-factor authentication (2FA)
Export user data feature (GDPR compliance)
API rate limiting
Webhook support for order events

Changed

Updated UI design for dashboard
Improved email templates
Database query optimization (40% faster)

Deprecated

GET /api/v1/users/list (use GET /api/v2/users instead)

Removed

Legacy authentication method (Basic Auth)

Fixed

Memory leak in background job processor
CORS issue with Safari browser
Timezone bug in date picker

Security

Updated dependencies (fixes CVE-2024-12345)
Implemented CSRF protection
Added helmet.js security headers

1.1.2 - 2025-01-08

Fixed

Critical bug in payment processing
Session timeout issue

1.1.0 - 2024-12-20

Added

User profile pictures
Email notifications
Search functionality

Changed

Redesigned login page
Improved mobile responsiveness

1.0.0 - 2024-12-01

Initial release

Added

User registration and authentication
Basic profile management
Product catalog
Shopping cart
Order management


### Step 2: Semantic Versioning

**Version number**: `MAJOR.MINOR.PATCH`

Given a version number MAJOR.MINOR.PATCH, increment:

MAJOR (1.0.0 → 2.0.0): Breaking changes

API changes break existing code
Example: adding required parameters, changing response structure

MINOR (1.1.0 → 1.2.0): Backward-compatible features

Add new features
Existing functionality continues to work
Example: new API endpoints, optional parameters

PATCH (1.1.1 → 1.1.2): Backward-compatible bug fixes

Bug fixes
Security patches
Example: fixing memory leaks, fixing typos


**Examples**:
- `1.0.0` → `1.0.1`: bug fix
- `1.0.1` → `1.1.0`: new feature
- `1.1.0` → `2.0.0`: Breaking change

### Step 3: Release Notes (user-friendly)

```markdown
# Release Notes v1.2.0
**Released**: January 15, 2025

## 🎉 What's New

### Two-Factor Authentication
You can now enable 2FA for enhanced security. Go to Settings > Security to set it up.

![2FA Setup](https://example.com/images/2fa.png)

### Export Your Data
We've added the ability to export all your data in JSON format. Perfect for backing up or migrating your account.

## ✨ Improvements

- **Faster Search**: Search is now 40% faster thanks to database optimizations
- **Better Emails**: Redesigned email templates for a cleaner look
- **Dashboard Refresh**: Updated UI with modern design

## 🐛 Bug Fixes

- Fixed a bug where password reset emails weren't being sent
- Resolved timezone issues in the date picker
- Fixed memory leak in background jobs

## ⚠️ Breaking Changes

If you're using our API:

- **Removed**: Basic Authentication is no longer supported
  - **Migration**: Use JWT tokens instead (see [Auth Guide](docs/auth.md))

- **Deprecated**: `GET /api/v1/users/list`
  - **Migration**: Use `GET /api/v2/users` with pagination

## 🔒 Security

- Updated all dependencies to latest versions
- Added CSRF protection to all forms
- Implemented security headers with helmet.js

## 📝 Full Changelog

See [CHANGELOG.md](CHANGELOG.md) for complete details.

---

**Upgrade Instructions**: [docs/upgrade-to-v1.2.md](docs/upgrade-to-v1.2.md)

Step 4: Breaking Changes migration guide

# Migration Guide: v1.x to v2.0

## Breaking Changes

### 1. Authentication Method Changed

**Before** (v1.x):
\`\`\`javascript
fetch('/api/users', {
  headers: {
    'Authorization': 'Basic ' + btoa(username + ':' + password)
  }
});
\`\`\`

**After** (v2.0):
\`\`\`javascript
// 1. Get JWT token
const { accessToken } = await fetch('/api/auth/login', {
  method: 'POST',
  body: JSON.stringify({ email, password })
}).then(r => r.json());

// 2. Use token
fetch('/api/users', {
  headers: {
    'Authorization': 'Bearer ' + accessToken
  }
});
\`\`\`

### 2. User List API Response Format

**Before** (v1.x):
\`\`\`json
{
  "users": [...]
}
\`\`\`

**After** (v2.0):
\`\`\`json
{
  "data": [...],
  "pagination": {
    "page": 1,
    "limit": 20,
    "total": 100
  }
}
\`\`\`

**Migration**:
\`\`\`javascript
// v1.x
const users = response.users;

// v2.0
const users = response.data;
\`\`\`

## Deprecation Timeline

- v2.0 (Jan 2025): Basic Auth marked as deprecated
- v2.1 (Feb 2025): Warning logs for Basic Auth usage
- v2.2 (Mar 2025): Basic Auth removed

Output format

CHANGELOG.md             # Developer-facing detailed log
RELEASES.md              # User-facing release notes
docs/migration/
  ├── v1-to-v2.md        # Migration guide
  └── v2-to-v3.md

Unreleased

Added

Changed

Fixed

1.2.0 - 2025-01-15

Added

Changed

Deprecated

Removed

Fixed

Security

1.1.2 - 2025-01-08

Fixed

1.1.0 - 2024-12-20

Added

Changed

1.0.0 - 2024-12-01

Added

Step 4: Breaking Changes migration guide

Output format

Constraints

Required rules (MUST)

Prohibited items (MUST NOT)

Best practices

References

Metadata

Version

Tags

Examples

Example 1: Basic usage

Example 2: Advanced usage

changelog-maintenance

Changelog Maintenance

When to use this skill

Instructions

Step 1: Keep a Changelog format