FastAPI Best Practices

FastAPI Best Practices

FastAPI done right. Async/sync endpoint selection, Depends() for dependency injection, Pydantic v2 models, lifespan context managers, BackgroundTasks, APIRouter, Annotated types, and production project structure.

AI coding assistants make every endpoint async, use global variables instead of Depends(), generate Pydantic v1 decorators, and put all routes in a single file. This plugin enforces the patterns that make FastAPI production-ready.

Install

Cursor / Claude Code / Windsurf

npx skills add ofershap/fastapi-best-practices

Or copy skills/ into your .cursor/skills/ or .claude/skills/ directory.

What's Included

Type	Name	Description
Skill	fastapi-best-practices	10 rules for async patterns, Depends(), Pydantic v2, lifespan, APIRouter, and more
Rule	best-practices	Always-on behavioral rule that enforces current FastAPI patterns
Command	/audit	Scan your codebase for FastAPI anti-patterns

What Agents Get Wrong

What the agent writes	What FastAPI best practice is
async def for everything	async def for I/O, def for CPU-bound
Global db variable	Depends(get_db) dependency injection
@validator, class Config	field_validator, ConfigDict (Pydantic v2)
@app.on_event("startup")	lifespan context manager
All routes in main.py	APIRouter with organized modules
asyncio.create_task()	BackgroundTasks for fire-and-forget work
return {"error": "not found"}	response_model + status.HTTP_404_NOT_FOUND

Related Plugins

• python-best-practices - Python 3.12+ type hints, Pydantic v2, uv, pathlib
• vibe-guard - Security guardrails for API endpoints

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Author

License

MIT