# Fastapi Templates

> Production-grade FastAPI project creation and setup guide. Includes async patterns, DI, and error handling. Triggers: "FastAPI", "Python API project", "FastAPI project creation", "FastAPI template", "FastAPI setup" Anti-triggers: "Django", "Flask", "Node.js API", "Express", "modifying existing FastAPI only"

- Skill: `jh941213/fastapi-templates-2` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jh941213/fastapi-templates-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jh941213/fastapi-templates-2/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: jh941213 (https://skillmd.com/u/jh941213)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/jh941213/fastapi-templates-2

---


# 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

## Implementation Patterns

### Pattern 1: Complete FastAPI Application

```python
# main.py
from fastapi import FastAPI, Depends
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager

@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan events."""
    # Startup
    await database.connect()
    yield
    # Shutdown
    await database.disconnect()

app = FastAPI(
    title="API Template",
    version="1.0.0",
    lifespan=lifespan
)

# CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
from app.api.v1.router import api_router
app.include_router(api_router, prefix="/api/v1")
```

## Resources

- **references/fastapi-architecture.md**: Detailed architecture guide
- **references/async-best-practices.md**: Async/await patterns
- **references/testing-strategies.md**: Comprehensive testing guide

## Best Practices

1. **Async All The Way**: Use async for database, external APIs
2. **Dependency Injection**: Leverage FastAPI's DI system
3. **Repository Pattern**: Separate data access from business logic
4. **Service Layer**: Keep business logic out of routes
5. **Pydantic Schemas**: Strong typing for request/response
6. **Error Handling**: Consistent error responses
7. **Testing**: Test all layers independently

## Common Pitfalls

- **Blocking Code in Async**: Using synchronous database drivers
- **No Service Layer**: Business logic in route handlers
- **Missing Type Hints**: Loses FastAPI's benefits
- **Ignoring Sessions**: Not properly managing database sessions
- **No Testing**: Skipping integration tests
- **Tight Coupling**: Direct database access in routes