FastAPI Development

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• Best Practices

Overview

Create fast, modern Python APIs using FastAPI with async/await support, automatic API documentation, type validation using Pydantic, dependency injection, JWT authentication, and SQLAlchemy ORM integration.

When to Use

• Building high-performance Python REST APIs
• Creating async API endpoints
• Implementing automatic OpenAPI/Swagger documentation
• Leveraging Python type hints for validation
• Building microservices with async support
• Integrating Pydantic for data validation

Quick Start

Minimal working example:

# main.py
from fastapi import FastAPI, HTTPException, status
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager
import logging

# Setup logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Create FastAPI instance
app = FastAPI(
    title="API Service",
    description="A modern FastAPI application",
    version="1.0.0",
    docs_url="/api/docs",
    openapi_url="/api/openapi.json"
)

# Add CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:3000"],
    allow_credentials=True,
    allow_methods=["*"],
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

| Guide | Contents | |---|---| | FastAPI Application Setup | FastAPI Application Setup | | Pydantic Models for Validation | Pydantic Models for Validation | | Async Database Models and Queries | Async Database Models and Queries | | Security and JWT Authentication | Security and JWT Authentication | | Service Layer for Business Logic | Service Layer for Business Logic | | API Routes with Async Endpoints | API Routes with Async Endpoints |

Best Practices

✅ DO

• Use async/await for I/O operations
• Leverage Pydantic for validation
• Use dependency injection for services
• Implement proper error handling with HTTPException
• Use type hints for automatic OpenAPI documentation
• Create service layers for business logic
• Implement authentication on protected routes
• Use environment variables for configuration
• Return appropriate HTTP status codes
• Document endpoints with docstrings and tags

❌ DON'T

• Use synchronous database operations
• Trust user input without validation
• Store secrets in code
• Ignore type hints
• Return database models in responses
• Implement authentication in route handlers
• Use mutable default arguments
• Forget to validate query parameters
• Expose stack traces in production