fastapi-templates

# FastAPI Project Templates Production-ready FastAPI project structures with async patterns, dependency injection, middleware, and best practices for building high-performance APIs. ## When to Use This Skill - Starting new FastAPI projects from scratch - Implementing async REST APIs with Python - Building high-performance web services and microservices - Creating async applications with PostgreSQL, MongoDB - Setting up API projects with proper structure and testing ## Core Concepts ### 1. Project Structure **Recommended Layout:** ``` app/ ├── api/ # API routes │ ├── v1/ │ │ ├── endpoints/ │ │ │ ├── users.py │ │ │ ├── auth.py │ │ │ └── items.py │ │ └── router.py │ └── dependencies.py # Shared dependencies ├── core/ # Core configuration │ ├── config.py │ ├── security.py │ └── database.py ├── models/ # Database models │ ├── user.py │ └── item.py ├── schemas/ # Pydantic schemas │ ├── user.py │ └── item.py ├── services/ # Business logic │ ├── user_service.py │ └── auth_service.py ├── repositories/ # Data access │ ├── user_repository.py │ └── item_repository.py └── main.py # Application entry ``` ### 2. Dependency Injection FastAPI's built-in DI system using `Depends`: - Database session management - Authentication/authorization - Shared business logic - Configuration injection ### 3. Async Patterns Proper async/await usage: - Async route handlers - Async database operations - Async background tasks - Async middleware ### 4. Dependencies The packages the examples import: ```text # requirements.txt fastapi uvicorn[standard] pydantic-settings sqlalchemy[asyncio]>=2.0 # DeclarativeBase; [asyncio] installs greenlet for the async engine asyncpg # PostgreSQL driver: postgresql+asyncpg://... PyJWT pwdlib[argon2] python-multipart # only for a login route that uses OAuth2PasswordRequestForm # requirements-dev.txt pytest pytest-asyncio httpx aiosqlite # test database: sqlite+aiosqlite:///:memory: ``` ## Detailed worked examples and patterns Detailed sections (starting with `## Implementation Patterns`) live in `references/details.md`. Read that file when the navigation summary above is insufficient. ## Testing ```python # tests/conftest.py import pytest_asyncio from httpx import ASGITransport, AsyncClient from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession from sqlalchemy.orm import sessionmaker from app.main import app from app.core.database import get_db, Base TEST_DATABASE_URL = "sqlite+aiosqlite:///:memory:" # Async fixtures need pytest_asyncio.fixture in pytest-asyncio's default strict mode @pytest_asyncio.fixture async def db_session(): engine = create_async_engine(TEST_DATABASE_URL, echo=True) async with engine.begin() as conn: await conn.run_sync(Base.metadata.create_all) AsyncSessionLocal = sessionmaker( engine, class_=AsyncSession, expire_on_commit=False ) async with AsyncSessionLocal() as session: yield session await engine.dispose() @pytest_asyncio.fixture async def client(db_session): async def override_get_db(): yield db_session app.dependency_overrides[get_db] = override_get_db # httpx 0.28 removed AsyncClient(app=...); use an ASGI transport transport = ASGITransport(app=app) async with AsyncClient(transport=transport, base_url="http://test") as client: yield client app.dependency_overrides.clear() # tests/test_users.py import pytest @pytest.mark.asyncio async def test_create_user(client): response = await client.post( "/api/v1/users/", json={ "email": "test@example.com", "password": "testpass123", "name": "Test User" } ) assert response.status_code == 201 data = response.json() assert data["email"] == "test@example.com" assert "id" in data ```