* ## Web Socket Lifecycle
 *
 * Upon normal operation each web socket progresses through a sequence of states:
 *
 *  * **Connecting:** the initial state of each web socket. Messages may be enqueued but they won't
 *    be transmitted until the web socket is open.
 *
 *  * **Open:** the web socket has been accepted by the remote peer and is fully operational.
 *    Messages in either direction are enqueued for immediate transmission.
 *

6. Here we are returning a dictionary that contains `items` which is a list of dataclasses.

    FastAPI is still capable of <dfn title="converting the data to a format that can be transmitted">serializing</dfn> the data to JSON.

7. Here the `response_model` is using a type annotation of a list of `Author` dataclasses.

    Again, you can combine `dataclasses` with standard type annotations.

        }
        return CacheStrategy(null, builder.build())
      }

      // Find a condition to add to the request. If the condition is satisfied, the response body
      // will not be transmitted.
      val conditionName: String
      val conditionValue: String?
      when {
        etag != null -> {
          conditionName = "If-None-Match"
          conditionValue = etag
        }

    This should make it easier to use OkHttp in Gradle plugins.

 *  Fix: Don't start the clock on response timeouts until the request body is fully transmitted.
    This is only relevant for duplex request bodies, because they are written concurrently when
    reading the response body.

    )
    val read = response1.body.source().read(ByteArray(8192))
    assertThat(read).isEqualTo(8192)

    // Make a second call that should transmit the response headers. The response body won't be
    // transmitted until the flow-control window is updated from the first request.
    val call2 = client.newCall(Request(server.url("/")))
    val response2 = call2.execute()
    assertThat(response2.code).isEqualTo(200)

  fun flushAfterStreamTransmittedWithNoLengthHeaders() {
    testFlushAfterStreamTransmitted(TransferKind.END_OF_STREAM)
  }

  /**
   * We explicitly permit apps to close the upload stream even after it has been transmitted.  We
   * also permit flush so that buffered streams can do a no-op flush when they are closed.
   * http://b/3038470
   */
  private fun testFlushAfterStreamTransmitted(transferKind: TransferKind) {

## Casos de uso { #use-cases }

Podrías usar esto si quieres transmitir strings puros, por ejemplo directamente de la salida de un servicio de AI LLM.

También podrías usarlo para transmitir archivos binarios grandes, donde transmites cada bloque de datos a medida que lo lees, sin tener que leerlo todo en memoria de una sola vez.

También podrías transmitir video o audio de esta manera; incluso podría generarse mientras lo procesas y lo envías.

{* ../../docs_src/custom_response/tutorial006c_py310.py hl[2,7,9] *}

### `StreamingResponse` { #streamingresponse }

Toma un generador `async` o un generador/iterador normal (una función con `yield`) y transmite el cuerpo del response.

{* ../../docs_src/custom_response/tutorial007_py310.py hl[3,16] *}

/// note | Nota Técnica

Vous pourriez ensuite mettre à jour `test_main.py` avec les tests étendus :

{* ../../docs_src/app_testing/app_b_an_py310/test_main.py *}


Chaque fois que vous avez besoin que le client transmette des informations dans la requête et que vous ne savez pas comment faire, vous pouvez chercher (Google) comment le faire avec `httpx`, ou même comment le faire avec `requests`, puisque la conception de HTTPX est basée sur celle de Requests.

Por exemplo, se você tivesse uma sessão de banco de dados em uma dependência com `yield`, o `StreamingResponse` não conseguiria usar essa sessão enquanto transmite dados, porque a sessão já teria sido fechada no código de saída após o `yield`.

Esse comportamento foi revertido na versão 0.118.0, para que o código de saída após o `yield` seja executado depois que a resposta for enviada.