Headers, Cookies, and Custom Responses
Read request headers and cookies, set them on responses, and return custom response types like plain text, HTML, redirects, and streaming in FastAPI.
Beyond the JSON Body
Request and response handling involves more than the JSON body. Headers and cookies carry metadata like auth tokens, content negotiation, and sessions. FastAPI gives you typed access to both.
Reading a Header
Declare a parameter with Header to read an incoming header. FastAPI auto-converts user_agent to the User-Agent header name.
from fastapi import FastAPI, Header
app = FastAPI()
@app.get('/info')
async def info(user_agent: str = Header(default=None)):
return {'ua': user_agent}All lessons in this course
- Pydantic Models for Request Body
- Response Models & Status Codes
- Form Data & File Uploads
- Headers, Cookies, and Custom Responses