# 서버 전송 이벤트(SSE) { #server-sent-events-sse }

브라우저 클라이언트로 데이터를 스트리밍하려면 **Server-Sent Events**(SSE)를 사용할 수 있습니다.

이는 [JSON Lines 스트리밍](stream-json-lines.md)과 비슷하지만, 브라우저가 기본적으로 [`EventSource` API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource)를 통해 지원하는 `text/event-stream` 형식을 사용합니다.

/// info | 정보

FastAPI 0.135.0에 추가되었습니다.

///

## Server-Sent Events란 { #what-are-server-sent-events }

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

**Server-Sent Events** (SSE) を使うと、クライアントへデータをストリーミングできます。

これは[JSON Lines のストリーミング](stream-json-lines.md)に似ていますが、`text/event-stream` フォーマットを使用します。これはブラウザがネイティブに [`EventSource` API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource) でサポートしています。

/// info | 情報

FastAPI 0.135.0 で追加されました。

///

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

Don't be all day about it!' and he went on in these words:

  `Yes, we went to school in the sea, though you mayn't believe
it--'

  `I never said I didn't!' interrupted Alice.

  `You did,' said the Mock Turtle.

  `Hold your tongue!' added the Gryphon, before Alice could speak
again.  The Mock Turtle went on.

  `We had the best of educations--in fact, we went to school

Don't be all day about it!' and he went on in these words:

  `Yes, we went to school in the sea, though you mayn't believe
it--'

  `I never said I didn't!' interrupted Alice.

  `You did,' said the Mock Turtle.

  `Hold your tongue!' added the Gryphon, before Alice could speak
again.  The Mock Turtle went on.

  `We had the best of educations--in fact, we went to school

{* ../../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`).

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")

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:

     *
     * @param primary true if primary
     */
    public void setPrimary(boolean primary) {
        this.isPrimary = primary;
    }

    /**
     * Get number of bytes sent
     *
     * @return bytes sent
     */
    public long getBytesSent() {
        return bytesSent.get();
    }

    /**
     * Get number of bytes received
     *
     * @return bytes received
     */

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

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