İstemciye veri akışını **Server-Sent Events** (SSE) ile sağlayabilirsiniz.

Bu, [JSON Lines Akışı](stream-json-lines.md) ile benzerdir ancak tarayıcılar tarafından yerel olarak desteklenen [`EventSource` API'si](https://developer.mozilla.org/en-US/docs/Web/API/EventSource) ile `text/event-stream` formatını kullanır.

/// info | Bilgi

FastAPI 0.135.0'da eklendi.

///

## Server-Sent Events Nedir? { #what-are-server-sent-events }

Это похоже на [Стриминг JSON Lines](stream-json-lines.md), но использует формат `text/event-stream`, который нативно поддерживается браузерами через [`EventSource` API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource).

/// info | Информация

Добавлено в FastAPI 0.135.0.

///

## Что такое Server-Sent Events? { #what-are-server-sent-events }

{* ../../docs_src/middleware/tutorial001_py310.py hl[8:9,11,14] *}

/// tip | Consejo

Ten en cuenta que los custom proprietary headers se pueden añadir [usando el prefijo `X-`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers).

また、`Response` はヘッダーや Cookie を設定するのによく使われるため、**FastAPI** は `fastapi.Response` でも提供しています。

///

## カスタムヘッダー { #custom-headers }

独自のカスタムヘッダーは、[`X-` プレフィックスを使って](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers)追加できることに注意してください。

/// note | Technische Details

Die Proxy-Header sind:

* [X-Forwarded-For](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For)
* [X-Forwarded-Proto](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Proto)
* [X-Forwarded-Host](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Host)

///

/// note | Détails techniques

Les en-têtes du proxy sont :

* [X-Forwarded-For](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For)
* [X-Forwarded-Proto](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Proto)
* [X-Forwarded-Host](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Host)

///

   * they can return ASCII characters that match real hostnames.
   */
  private fun String.asciiToLowercase(): String =
    when {
      isAscii() -> lowercase(Locale.US)

      // This is an ASCII string.
      else -> this
    }

  /** Returns true if the [String] is ASCII encoded (0-127). */
  private fun String.isAscii() = length == utf8Size().toInt()

  /**

      }
      result.add(Header(TARGET_SCHEME, request.url.scheme))

      for (i in 0 until headers.size) {
        // header names must be lowercase.
        val name = headers.name(i).lowercase(Locale.US)
        if (name !in HTTP_2_SKIPPED_REQUEST_HEADERS ||
          name == TE &&
          headers.value(i) == "trailers"
        ) {
          result.add(Header(name, headers.value(i)))
        }
      }

# WebSockets { #websockets }

Puedes usar [WebSockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API) con **FastAPI**.

## Instalar `websockets` { #install-websockets }

Asegúrate de crear un [entorno virtual](../virtual-environments.md), activarlo e instalar `websockets` (un paquete de Python que facilita usar el protocolo "WebSocket"):

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

        assertFalse(result.isPresent());
    }

    @Test
    public void test_determineAlias_multipleLocales() {
        // Test with various locale configurations
        Locale[] testLocales = { Locale.US, Locale.UK, Locale.CANADA, Locale.FRANCE, Locale.CHINA, Locale.KOREA, new Locale("es", "ES"),
                new Locale("pt", "BR") };

        for (Locale locale : testLocales) {