Generate a Complete REST API with Gemini Code Assist

Design and implement a complete REST API for a [DOMAIN] application. Generate all the following components:

**1. Data Models** (define first):
- Entity definitions with field types, constraints, and relationships
- Database schema (SQL or ORM model definitions)
- Validation rules for each entity

**2. API Endpoints** (for each entity):
- GET /api/[resource] — List with pagination, filtering, sorting
- GET /api/[resource]/:id — Single item with related data
- POST /api/[resource] — Create with validation
- PUT /api/[resource]/:id — Full update
- PATCH /api/[resource]/:id — Partial update
- DELETE /api/[resource]/:id — Soft delete

**3. Middleware**:
- Authentication (JWT or API key)
- Rate limiting
- Request logging
- CORS configuration
- Error handling middleware

**4. Business Logic**:
- Service layer with business rules
- Input sanitization
- Pagination helpers
- Response formatting (consistent envelope)

**5. Documentation**:
- OpenAPI 3.1 spec for all endpoints
- Example requests and responses

Use [LANGUAGE/FRAMEWORK] and follow its idiomatic patterns.