fastapi-templates

Source Statement: The content of this skill is derived from wshobson/agents (MIT License, Copyright (c) 2024 Seth Hobson; the full license text is available in the same directory LICENSE.txt). Use, modification, and redistribution must comply with the terms of this MIT License and retain the copyright notice.

Chinese Description

This skill provides guidance on best practices and patterns related to full-stack development.

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name: fastapi-templates description: Create production-ready FastAPI projects with async patterns, dependency injection, and comprehensive error handling. Use when building new FastAPI applications or setting up backend API projects.

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

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

# tests/conftest.py
import pytest
import asyncio
from httpx import 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:"

@pytest.fixture(scope="session")
def event_loop():
    loop = asyncio.get_event_loop_policy().new_event_loop()
    yield loop
    loop.close()

@pytest.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

@pytest.fixture
async def client(db_session):
    async def override_get_db():
        yield db_session

    app.dependency_overrides[get_db] = override_get_db

    async with AsyncClient(app=app, base_url="http://test") as client:
        yield client

# 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

Capability Boundaries

✅ Good at handling

• Best practices related to full-stack development
• Code architecture design guidance
• Performance optimization suggestions

⚠️ Requires input

• Specific project context
• Technology stack information

❌ Out of scope

• Business decisions in non-technical domains
• Specific code implementation (guidance only)

Workflow

Step 1: Requirements Analysis

Understand project requirements and technical constraints

Step 2: Architecture Design

Design system architecture and component division

Step 3: Implementation Guidance

Provide specific implementation suggestions and code patterns

Step 4: Code Review

Review code quality and adherence to best practices

Step 5: Optimization Suggestions

Provide performance optimization and improvement suggestions

Gotchas

1. Overengineering

Avoid using complex design patterns in simple scenarios

2. Ignoring Performance

Do not ignore performance optimization, especially in production environments

3. Security Considerations

Always consider security and data protection

4. Test Coverage

Ensure sufficient test coverage, especially edge cases

5. Documentation Maintenance

Keep documentation updated in sync with the code