fastapi-pro · diff
git:20260926.941aa31 to git:20261014.522e28a
1 added, 1 removed. Audit A to A.
---
name: fastapi-pro
- description: Guides development of high-performance asynchronous FastAPI applications with Pydantic v2 schemas, dependency injection, structured error handling, background tasks, and production OpenAPI documentation.
+ description: "Builds async FastAPI apps: Pydantic v2 schemas, dependency injection, structured errors, background tasks, OpenAPI docs. Use for 'build a FastAPI endpoint' or 'structure this FastAPI app'."
---
# FastAPI Pro (Production-Ready Async Python)
## Overview
FastAPI is the standard for high-performance Python backends and AI microservices. `fastapi-pro` enforces modern asynchronous best practices, clean layered architecture, and robust type safety with Pydantic v2.
## Architectural Best Practices
### 1. Clean Layered Architecture
```text
app/
├── api/
│ ├── v1/
│ │ ├── endpoints/ # Route handlers (thin controllers)
│ │ └── router.py # Centralized APIRouter aggregation
│ └── deps.py # Reusable Depends() providers (Auth, DB session, Client)
├── core/
│ ├── config.py # Pydantic BaseSettings with .env validation
│ ├── errors.py # Global exception handlers
│ └── security.py # JWT, hashing, API key verification
├── models/ # SQLAlchemy / SQLModel database entities
├── schemas/ # Pydantic v2 request / response models
├── services/ # Pure business logic and LLM orchestration
└── db/ # Engine, sessionmaker, migrations (Alembic)
```
### 2. Modern Pydantic v2 Patterns
- Always use `model_config = ConfigDict(from_attributes=True, populate_by_name=True)`.
- Explicit request/response typing on all endpoints: `response_model=CustomResponseSchema`.
### 3. Asynchronous Best Practices
- Never use blocking synchronous I/O inside `async def` route handlers (e.g. `requests.get()`, `time.sleep()`).
- Use `httpx.AsyncClient` or `aiohttp` for non-blocking HTTP requests.
- For heavy CPU-bound tasks, offload to `asyncio.to_thread` or background task queues (Celery/ARQ/BullMQ).