AmzMetaUnencryptedContentLength = "X-Amz-Meta-X-Amz-Unencrypted-Content-Length"
	AmzMetaUnencryptedContentMD5    = "X-Amz-Meta-X-Amz-Unencrypted-Content-Md5"

	// AWS server-side encryption headers for SSE-S3, SSE-KMS and SSE-C.
	AmzServerSideEncryption                      = "X-Amz-Server-Side-Encryption"
	AmzServerSideEncryptionKmsID                 = AmzServerSideEncryption + "-Aws-Kms-Key-Id"

And as the `Response` can be used frequently to set headers and cookies, **FastAPI** also provides it at `fastapi.Response`.

///

## Custom Headers

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

Y como la `Response` puede ser usada frecuentemente para configurar headers y cookies, **FastAPI** también la provee en `fastapi.Response`.

///

## Headers Personalizados

Ten en cuenta que se pueden añadir headers propietarios personalizados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando el prefijo 'X-'</a>.

///

## Cabeçalhos personalizados

Tenha em mente que cabeçalhos personalizados proprietários podem ser adicionados <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">usando o prefixo 'X-'</a>.

///

## Benutzerdefinierte Header

Beachten Sie, dass benutzerdefinierte proprietäre Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

 & `Response` 💪 ⚙️ 🛎 ⚒ 🎚 & 🍪, **FastAPI** 🚚 ⚫️ `fastapi.Response`.

///

## 🛃 🎚

✔️ 🤯 👈 🛃 © 🎚 💪 🚮 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">⚙️ '✖-' 🔡</a>.

Sebastián Ramírez <******@****.***> 1728247014 +0200

  /** The HTTP {@code Accept-Language} header field name. */
  public static final String ACCEPT_LANGUAGE = "Accept-Language";
  /** The HTTP {@code Access-Control-Request-Headers} header field name. */
  public static final String ACCESS_CONTROL_REQUEST_HEADERS = "Access-Control-Request-Headers";
  /** The HTTP {@code Access-Control-Request-Method} header field name. */
  public static final String ACCESS_CONTROL_REQUEST_METHOD = "Access-Control-Request-Method";

```

////

/// warning

Before setting `convert_underscores` to `False`, bear in mind that some HTTP proxies and servers disallow the usage of headers with underscores.

///

## Duplicate headers

It is possible to receive duplicate headers. That means, the same header with multiple values.

You can define those cases using a list in the type declaration.

```

////

**FastAPI** will **extract** the data for **each field** from the **headers** in the request and give you the Pydantic model you defined.

## Check the Docs

You can see the required headers in the docs UI at `/docs`:

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

## Forbid Extra Headers