```
### Maintain a Migration Guide
For each major version, provide:
1. **What changed** - Breaking changes summary
2. **Why it changed** - Context for the decisions
3. **How to migrate** - Step-by-step instructions
4. **Timeline** - When old versions will be deprecated
```markdown
## Migrating from v2 to v3
### Breaking Changes
| v2 | v3 | Migration |
|----|----| --------|
| `api_key` header | `Authorization: Bearer` | Update all API calls |
| `/users/list` | `/users` | Update endpoint URLs |
| Sync responses | Async with webhooks | Implement webhook handler |
### Step-by-Step Migration
1. Generate a new v3 API token in your dashboard
2. Update your SDK to version 3.x
3. Replace authentication headers...
```
### Deprecation Timeline
Communicate clearly when versions will be sunset:
```markdown
## Version Support Policy
| Version | Status | End of Life |
|---------|--------|-------------|
| v3 | Current | - |
| v2 | Maintenance | December 2025 |
| v1 | Deprecated | March 2025 |
**Maintenance mode**: Security fixes only, no new features.
**Deprecated**: No updates, removal scheduled.
```
## SEO Considerations
### Canonical URLs
Point all version URLs to the latest as canonical (unless targeting specific version keywords):
```html