# WebSockets

Sie können <a href="https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API" class="external-link" target="_blank">WebSockets</a> mit **FastAPI** verwenden.

## `WebSockets` installieren

Zuerst müssen Sie `WebSockets` installieren:

<div class="termy">

```console
$ pip install websockets

---> 100%
```

</div>

## WebSockets-Client

### In Produktion

```

::: fastapi.WebSocketDisconnect

## WebSockets - additional classes

Additional classes for handling WebSockets.

Provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi.websockets import WebSocketDisconnect, WebSocketState
```

::: fastapi.websockets.WebSocketDisconnect

# Testing WebSockets

You can use the same `TestClient` to test WebSockets.

For this, you use the `TestClient` in a `with` statement, connecting to the WebSocket:

```Python hl_lines="27-31"
{!../../../docs_src/app_testing/tutorial002.py!}
```

!!! note

          text: String,
        ) {
          webSocket.send(text)
        }

        override fun onClosing(
          webSocket: WebSocket,
          code: Int,
          reason: String,
        ) {
          webSocket.close(1000, null)
          latch.countDown()
        }

        override fun onFailure(
          webSocket: WebSocket,
          t: Throwable,
          response: Response?,

= vendor/github.com/tmc/grpc-websocket-proxy licensed under: =

Copyright (C) 2016 Travis Cline

import java.util.Date

/**
 * A received response or failure recorded by the response recorder.
 */
class RecordedResponse(
  @JvmField val request: Request,
  val response: Response?,
  val webSocket: WebSocket?,
  val body: String?,
  val failure: IOException?,
) {
  fun assertRequestUrl(url: HttpUrl) =
    apply {
      assertThat(request.url).isEqualTo(url)
    }

  fun assertRequestMethod(method: String) =

        minimumDeflateSize = 0L,
        webSocketCloseTimeout = RealWebSocket.CANCEL_AFTER_CLOSE_MILLIS,
      )
    val name = "MockWebServer WebSocket ${request.path!!}"
    webSocket.initReaderAndWriter(name, streams)
    try {
      webSocket.loopReader(fancyResponse)

      // Even if messages are no longer being read we need to wait for the connection close signal.
      connectionClose.await()

}

public abstract class okhttp3/WebSocketListener {
	public fun <init> ()V
	public fun onClosed (Lokhttp3/WebSocket;ILjava/lang/String;)V
	public fun onClosing (Lokhttp3/WebSocket;ILjava/lang/String;)V
	public fun onFailure (Lokhttp3/WebSocket;Ljava/lang/Throwable;Lokhttp3/Response;)V
	public fun onMessage (Lokhttp3/WebSocket;Ljava/lang/String;)V

import okhttp3.internal.ws.WebSocketProtocol.toggleMask
import okio.Buffer
import okio.BufferedSource
import okio.ByteString

/**
 * An [RFC 6455][rfc_6455]-compatible WebSocket frame reader.
 *
 * This class is not thread safe.
 *
 * [rfc_6455]: http://tools.ietf.org/html/rfc6455
 */
class WebSocketReader(
  private val isClient: Boolean,
  val source: BufferedSource,

## 0.24.0

* Add support for WebSockets with dependencies and parameters.
    * Support included for:
        * `Depends`
        * `Security`
        * `Cookie`
        * `Header`
        * `Path`
        * `Query`
        * ...as these are compatible with the WebSockets protocol (e.g. `Body` is not).
    * [Updated documentation for WebSockets](https://fastapi.tiangolo.com/advanced/websockets/).