# Header Parameters { #header-parameters }

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

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

First import `Header`:

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

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

# Parâmetros de Cabeçalho { #header-parameters }

Você pode definir parâmetros de Cabeçalho da mesma maneira que define paramêtros com `Query`, `Path` e `Cookie`.

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

Primeiro importe `Header`:

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

## Declare parâmetros de `Header` { #declare-header-parameters }

func setEventStreamHeaders(w http.ResponseWriter) {
	w.Header().Set(xhttp.ContentType, "text/event-stream")
	w.Header().Set(xhttp.CacheControl, "no-cache") // nginx to turn off buffering
	w.Header().Set("X-Accel-Buffering", "no")      // nginx to turn off buffering
}

// Write http common headers
func setCommonHeaders(w http.ResponseWriter) {
	// Set the "Server" http header.
	w.Header().Set(xhttp.ServerInfo, MinioStoreName)

# Header-параметры { #header-parameters }

Вы можете определить параметры заголовка таким же образом, как вы определяете параметры `Query`, `Path` и `Cookie`.

## Импорт `Header` { #import-header }

Сперва импортируйте `Header`:

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

## Объявление параметров `Header` { #declare-header-parameters }

# Header Parameter Models { #header-parameter-models }

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

	AmzFwdHeaderChecksumSha1       = "x-amz-fwd-header-x-amz-checksum-sha1"
	AmzFwdHeaderChecksumSha256     = "x-amz-fwd-header-x-amz-checksum-sha256"
	AmzFwdHeaderDeleteMarker       = "x-amz-fwd-header-x-amz-delete-marker"
	AmzFwdHeaderETag               = "x-amz-fwd-header-ETag"
	AmzFwdHeaderExpires            = "x-amz-fwd-header-Expires"
	AmzFwdHeaderExpiration         = "x-amz-fwd-header-x-amz-expiration"

}

// readGNUSparsePAXHeaders checks the PAX headers for GNU sparse headers.
// If they are found, then this function reads the sparse map and returns it.
// This assumes that 0.0 headers have already been converted to 0.1 headers
// by the PAX header parsing logic.
func (tr *Reader) readGNUSparsePAXHeaders(hdr *Header) (sparseDatas, error) {
	// Identify the version of GNU headers.
	var is1x0 bool

您可以在文档 UI 的 `/docs` 中查看所需的 headers：

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

## 禁止额外的 Headers

在某些特殊使用情况下（可能并不常见），您可能希望**限制**您想要接收的 headers。

您可以使用 Pydantic 的模型配置来禁止（ `forbid` ）任何额外（ `extra` ）字段：

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

如果客户尝试发送一些**额外的 headers**，他们将收到**错误**响应。

Declara los **parámetros de header** que necesitas en un **modelo Pydantic**, y luego declara el parámetro como `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI** **extraerá** los datos para **cada campo** de los **headers** en el request y te dará el modelo Pydantic que definiste.

## Revisa la Documentación { #check-the-docs }

Você pode ver os headers necessários na interface gráfica da documentação em `/docs`:

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

## Proibindo Cabeçalhos adicionais { #forbid-extra-headers }

Em alguns casos de uso especiais (provavelmente não muito comuns), você pode querer **restringir** os cabeçalhos que você quer receber.