Building APIs with FastAPI and Python

Why FastAPI?

FastAPI is arguably the best way to build APIs in Python today. It leverages Python type hints to provide automatic data validation and generates interactive API documentation (Swagger UI) out of the box.

Hello World in FastAPI

python
from fastapi import FastAPI

app = FastAPI()

@app.get("/")
def read_root():
    return {"Hello": "World"}

Automatic Validation

By using Pydantic models, FastAPI ensures that any JSON payload sent to your API matches your expected schema perfectly, throwing helpful 422 errors if data is missing or incorrectly typed.