# TradeSense AI — API Versioning & Contract Policy (Milestone 17)

**Document Version**: `1.7.0-API-POLICY`  

---

## 1. Versioning Standards

- **Canonical Path**: All endpoints reside under `/api/v1/`.
- **Breaking Change Policy**: Breaking changes require a new path prefix (`/api/v2/`) with a 12-month deprecation window for `/api/v1/`.
- **Standard Error Contract**:
```json
{
  "error": {
    "code": "HTTP_404",
    "message": "Resource not found",
    "request_id": "req_a1b2c3d4"
  }
}
```