from typing import Union

from fastapi import FastAPI
from fastapi.testclient import TestClient
from pydantic import BaseModel, ConfigDict


class FooBaseModel(BaseModel):
    model_config = ConfigDict(extra="forbid")


class Foo(FooBaseModel):
    pass


app = FastAPI()


@app.post("/")
async def post(
    foo: Union[Foo, None] = None,
):
    return foo


client = TestClient(app)

* [Forbid Extra Query Parameters](https://fastapi.tiangolo.com/tutorial/query-param-models/#forbid-extra-query-parameters)
* [Forbid Extra Headers](https://fastapi.tiangolo.com/tutorial/header-param-models/#forbid-extra-headers)
* [Forbid Extra Cookies](https://fastapi.tiangolo.com/tutorial/cookie-param-models/#forbid-extra-cookies)

### Features