But even if you **fill the data** and click "Execute", because the docs UI works with **JavaScript**, the cookies won't be sent, and you will see an **error** message as if you didn't write any values.

///

## Forbid Extra Cookies { #forbid-extra-cookies }

In some special use cases (probably not very common), you might want to **restrict** the cookies that you want to receive.

Puedes verificarlo en la interfaz de documentación en `/docs`:

<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Prohibir Campos de Formulario Extra { #forbid-extra-form-fields }

En algunos casos de uso especiales (probablemente no muy comunes), podrías querer **restringir** los campos de formulario a solo aquellos declarados en el modelo de Pydantic. Y **prohibir** cualquier campo **extra**.

<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Prohibir Parámetros Query Extras { #forbid-extra-query-parameters }

En algunos casos de uso especiales (probablemente no muy comunes), podrías querer **restringir** los parámetros query que deseas recibir.

Puedes usar la configuración del modelo de Pydantic para `forbid` cualquier campo `extra`:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

///

## Запрет дополнительных cookies { #forbid-extra-cookies }

В некоторых случаях (не особо часто встречающихся) вам может понадобиться **ограничить** cookies, которые вы хотите получать.

///

## Zusätzliche Cookies verbieten { #forbid-extra-cookies }

In einigen speziellen Anwendungsfällen (wahrscheinlich nicht sehr häufig) möchten Sie möglicherweise die Cookies, die Sie empfangen möchten, **einschränken**.

from fastapi import FastAPI, Form
from pydantic import BaseModel

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str
    model_config = {"extra": "forbid"}


@app.post("/login/")
async def login(data: FormData = Form()):

from typing import Union

from fastapi import Cookie, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Cookies(BaseModel):
    model_config = {"extra": "forbid"}

    session_id: str
    fatebook_tracker: Union[str, None] = None
    googall_tracker: Union[str, None] = None


@app.get("/items/")
async def read_items(cookies: Cookies = Cookie()):

from typing import Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    model_config = {"extra": "forbid"}

    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")

from typing import Annotated, Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    model_config = {"extra": "forbid"}

    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")

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)