fastapi-patternslisted
Install: claude install-skill TeiNam/my_harness_for_claude_code
# FastAPI Patterns
Production-oriented patterns for FastAPI services.
## When to Use
- Building or reviewing a FastAPI app.
- Splitting routers, schemas, dependencies, and database access.
- Writing async endpoints that call a database or external service.
- Adding authentication, authorization, OpenAPI docs, tests, or deployment settings.
- Checking a FastAPI PR for copy-pasteable examples and production risks.
## How It Works
Treat the FastAPI app as a thin HTTP layer over explicit dependencies and service code:
- `main.py` owns app construction, middleware, exception handlers, and router registration.
- `schemas/` owns Pydantic request and response models.
- `dependencies.py` owns database, auth, pagination, and request-scoped dependencies.
- `services/` or `crud/` owns business and persistence operations.
- `tests/` overrides dependencies instead of opening production resources.
Prefer small routers and explicit `response_model` declarations. Keep raw ORM objects, secrets, and framework globals out of response schemas.
## Project Layout
```text
app/
|-- main.py
|-- config.py
|-- dependencies.py
|-- exceptions.py
|-- api/
| `-- routes/
| |-- users.py
| `-- health.py
|-- core/
| |-- security.py
| `-- middleware.py
|-- db/
| |-- session.py
| `-- crud.py
|-- models/
|-- schemas/
`-- tests/
```
## Application Factory
Use a factory so tests and workers can build the app with controlled settings.
```python
from contextlib import asynccontextmana