# Parámetros de Header { #header-parameters }

Puedes definir los parámetros de Header de la misma manera que defines los parámetros de `Query`, `Path` y `Cookie`.

## Importar `Header` { #import-header }

Primero importa `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declarar parámetros de `Header` { #declare-header-parameters }

```

Read the new docs: [Query Parameter Models](https://fastapi.tiangolo.com/tutorial/query-param-models/).

#### `Header` Parameter Models

Use Pydantic models for `Header` parameters:

```python
from typing import Annotated

from fastapi import FastAPI, Header
from pydantic import BaseModel

app = FastAPI()


class CommonHeaders(BaseModel):
    host: str

Sehen wir uns zunächst an, wie Editor, mypy und andere Tools dies sehen würden.

`BaseUser` verfügt über die Basis-Felder. Dann erbt `UserIn` von `BaseUser` und fügt das Feld `password` hinzu, sodass es nun alle Felder beider Modelle hat.

Wir annotieren den Funktionsrückgabetyp als `BaseUser`, geben aber tatsächlich eine `UserIn`-Instanz zurück.

Возможно, вы захотите попробовать их сервисы и воспользоваться их руководствами:

* <a href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" class="external-link" target="_blank">Render</a>

  - svixhq
  - Alek99
  - codacy
  - zanfaruqui
  - scalar
  - bump-sh
  - andrew-propelauth
  - svix
  - zuplo-oss
  - zuplo
  - Kong
  - speakeasy-api
  - jess-render
  - blockbee-io
  - liblaber
  - render-sponsorships
  - renderinc
  - stainless-api
  - snapit-cypher
  - coderabbitai
  - permitio
  - LambdaTest-Inc
  - dribia
  - madisonredtfeldt
  - railwayapp
  - subtotal

También podrías considerarlos para seguir sus guías y probar sus servicios:

* <a href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" class="external-link" target="_blank">Render</a>

Você também pode considerá-los para seguir seus tutoriais e experimentar seus serviços:

* <a href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" class="external-link" target="_blank">Render</a>

* Import `Jinja2Templates`.
* Create a `templates` object that you can reuse later.
* Declare a `Request` parameter in the *path operation* that will return a template.
* Use the `templates` you created to render and return a `TemplateResponse`, pass the name of the template, the request object, and a "context" dictionary with key-value pairs to be used inside of the Jinja2 template.

    <div class="item">
      <a title="Deploy & scale any full-stack web app on Render. Focus on building apps, not infra." style="display: block; position: relative;" href="https://docs.render.com/deploy-fastapi?utm_source=deploydoc&utm_medium=referral&utm_campaign=fastapi" target="_blank">
        <span class="sponsor-badge">sponsor</span>
        <img class="sponsor-image" src="/img/sponsors/render-banner.svg" />
      </a>
    </div>
    <div class="item">

from typing import Any

import orjson
from fastapi import FastAPI, Response

app = FastAPI()


class CustomORJSONResponse(Response):
    media_type = "application/json"

    def render(self, content: Any) -> bytes:
        assert orjson is not None, "orjson must be installed"
        return orjson.dumps(content, option=orjson.OPT_INDENT_2)


@app.get("/", response_class=CustomORJSONResponse)
async def main():