**Example**

        ```python
        from fastapi import FastAPI, WebSocket

        app = FastAPI()

        @app.websocket("/ws")
        async def websocket_endpoint(websocket: WebSocket):
            await websocket.accept()
            while True:
                data = await websocket.receive_text()

It has an interesting, uncommon feature: using the same framework, it's possible to create APIs and also CLIs.

As it is based on the previous standard for synchronous Python web frameworks (WSGI), it can't handle Websockets and other things, although it still has high performance too.

/// info

* **GraphQL** integration with <a href="https://strawberry.rocks" class="external-link" target="_blank">Strawberry</a> and other libraries.
* Many extra features (thanks to Starlette) as:
    * **WebSockets**
    * extremely easy tests based on HTTPX and `pytest`
    * **CORS**
    * **Cookie Sessions**
    * ...and more.

## Performance

A pesar de que la especificación principal para Python web asíncrono (ASGI) se desarrolló en Django, para agregar soporte para WebSockets.

Ese tipo de asincronía es lo que hizo popular a NodeJS (aunque NodeJS no es paralelo) y esa es la fortaleza de Go como lenguaje de programación.

Y ese es el mismo nivel de rendimiento que obtienes con **FastAPI**.

  /** Uses [request] to connect a new web socket. */
  override fun newWebSocket(
    request: Request,
    listener: WebSocketListener,
  ): WebSocket {
    val webSocket =
      RealWebSocket(
        taskRunner = taskRunner,
        originalRequest = request,
        listener = listener,
        random = Random(),

- RemoteCommand feature gates for kubectl exec, cp, and attach over WebSockets are now enabled by default (Beta):
  - Server-side feature gate: `TranslateStreamCloseWebsocketRequests`
  - Client-side (kubectl) feature gate: `KUBECTL_REMOTE_COMMAND_WEBSOCKETS`

 *  Fix: The previous release introduced a performance regression on Android,
    caused by looking up CA certificates. This is now fixed.


## Version 3.1.0

_2016-02-06_

 *  New: WebSockets now defer some writes. This should improve performance for
    some applications.
 *  New: Override `equals()` and `hashCode()` in our new cookie class. This
    class now defines equality by value rather than by reference.

 * limitations under the License.
 */
package okhttp3

import okio.ByteString

/**
 * A non-blocking interface to a web socket. Use the [factory][WebSocket.Factory] to create
 * instances; usually this is [OkHttpClient].
 *
 * ## Web Socket Lifecycle
 *
 * Upon normal operation each web socket progresses through a sequence of states:
 *

- Enabled feature gates for PortForward (kubectl port-forward) over WebSockets by default (beta).
   - Server-side feature gate: PortForwardWebsocket
   - Client-side (kubectl) feature gate: PORT_FORWARD_WEBSOCKETS environment variable

// when using WebSockets.
// The `port` query parameter must specify the port or
// ports (comma separated) to forward over.
// Port forwarding over SPDY does not use these options. It requires the port
// to be passed in the `port` header as part of request.
message PodPortForwardOptions {
  // List of ports to forward
  // Required when using WebSockets
  // +optional
  repeated int32 ports = 1;