FastAPI Basics: Building a Simple REST API

FastAPI is a modern, high-performance web framework for building APIs with Python 3.6+.

Installation

pip install fastapi uvicorn 

Basic Example

from fastapi import FastAPI app = FastAPI() @app.get("/") def read_root(): return {"Hello": "World"} @app.get("/items/{item_id}") def read_item(item_id: int, q: float = None): return {"item_id": item_id, "q": q} 

Run the server:

uvicorn main:app --reload 

Visit http://127.0.0.1:8000/docs for interactive Swagger UI.

Conclusion

FastAPI provides automatic documentation and high performance, making it ideal for building APIs quickly.