# Server-Sent Events (SSE) { #server-sent-events-sse }

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.

///

# События, отправляемые сервером (SSE) { #server-sent-events-sse }

Вы можете передавать данные потоком клиенту, используя Server-Sent Events (SSE).

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.

///

{* ../../docs_src/stream_json_lines/tutorial001_py310.py ln[33:36] hl[34] *}

## Server-Sent Events (SSE) { #server-sent-events-sse }

    return v


class ServerSentEvent(BaseModel):
    """Represents a single Server-Sent Event.

    When `yield`ed from a *path operation function* that uses
    `response_class=EventSourceResponse`, each `ServerSentEvent` is encoded
    into the [SSE wire format](https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream)
    (`text/event-stream`).

    client.webSocket!!.finishReader()
    taskFaker.runTasks()
    assertThat(client.closed).isTrue()
    client.listener.assertFailure(
      ProtocolException::class.java,
      "Server-sent frames must not be masked.",
    )
    server.listener.assertClosing(1000, "Hello")
    server.listener.assertExhausted() // Client should not have sent second close.
  }

  @Test

     */
    int NTLMSSP_NEGOTIATE_ALWAYS_SIGN = 0x00008000;

    /**
     * Sent by the server in the Type 2 message to indicate that the
     * target authentication realm is a domain.
     */
    int NTLMSSP_TARGET_TYPE_DOMAIN = 0x00010000;

    /**
     * Sent by the server in the Type 2 message to indicate that the
     * target authentication realm is a server.
     */

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

OkHttp Server-Sent Events
=========================

Experimental support for server-sent events.
API is not considered stable and may change at any time.

### Download

```kotlin
testImplementation("com.squareup.okhttp3:okhttp-sse:5.3.0")

                """
                The function to call after the response is sent.

                It can be a regular `def` function or an `async def` function.
                """
            ),
        ],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> None:
        """
        Add a function to be called in the background after the response is sent.

        Read more about it in the

async def create_file(file: Annotated[bytes | None, File()] = None):
    if not file:
        return {"message": "No file sent"}
    else:
        return {"file_size": len(file)}


@app.post("/uploadfile/")
async def create_upload_file(file: UploadFile | None = None):
    if not file:
        return {"message": "No upload file sent"}
    else: