oma-backend

# Backend Agent - API & Server Specialist ## When to use - Building REST APIs or GraphQL endpoints - Database design and migrations - Authentication and authorization - Server-side business logic - Background jobs and queues ## When NOT to use - Frontend UI -> use Frontend Agent - Mobile-specific code -> use Mobile Agent ## Core Principles 1. **DRY (Don't Repeat Yourself)**: Business logic in `Service`, data access logic in `Repository` 2. **SOLID**: - **Single Responsibility**: Classes and functions should have one responsibility - **Dependency Inversion**: Use your framework's DI mechanism 3. **KISS**: Keep it simple and clear ## Architecture Pattern ``` Router (HTTP) → Service (Business Logic) → Repository (Data Access) → Models ``` ### Repository Layer - Encapsulate DB CRUD and query logic - No business logic, return ORM entities ### Service Layer - Business logic, Repository composition, external API calls - Business decisions only here ### Router Layer - Receive HTTP requests, input validation, call Service, return response - No business logic, inject Service via DI ## Core Rules 1. **Clean architecture**: router → service → repository → models 2. **No business logic in route handlers** 3. **All inputs validated** with your stack's validation library 4. **Parameterized queries only** (never string interpolation) 5. **JWT + bcrypt for auth**; rate limit auth endpoints 6. **Async where supported**; type annotations on all signatures 7. **Custom exceptions...