A small example of a fastAPI server with JWT token

fastapi_server.py

import jwt
from fastapi import FastAPI, Header
from pydantic import BaseModel
from typing import Optional

JWT_SECRET = "secret" # IRL we should NEVER hardcode the secret: it should be an evironment variable!!!
JWT_ALGORITHM = "HS256"

app = FastAPI()

class Person(BaseModel):
    name: str
    gender: Optional[str] = None
    age: float
    checked: Optional[bool] = None

@app.post("/")
async def root(person: Person, authorization: str = Header(None)):
    try:
        decoded = secure(authorization)
        # here we can add code to check the user (by email)
        # e.g. select the user from the DB and see its permissions
    except:
        return "Unauthorized Access!"
    # in this example we'll simply return the person entity from the request body
    # after adding a "checked"
    person.checked = True
    return person    

def secure(token):
    # if we want to sign/encrypt the JSON object: {"hello": "world"}, we can do it as follows
    # encoded = jwt.encode({"hello": "world"}, JWT_SECRET, algorithm=JWT_ALGORITHM)
    decoded_token = jwt.decode(token, JWT_SECRET, algorithms=JWT_ALGORITHM)
    # this is often used on the client side to encode the user's email address or other properties
    return decoded_token