> ## Documentation Index
> Fetch the complete documentation index at: https://gccai.heqingsong.uk/llms.txt
> Use this file to discover all available pages before exploring further.

# 音乐延伸

> Flow Music 对已生成的音频续写。从指定时间点开始，按编辑指令延伸音乐

<RequestExample>
  ```bash cURL theme={null}
  curl --request POST \
    --url https://gccai.heqingsong.uk/v1/music/generations/extendFlowMusic \
    --header 'Authorization: Bearer <token>' \
    --header 'Content-Type: application/json' \
    --data '{
      "model": "flowmusic",
      "clip_id": "abc123-def456",
      "extend_from_s": 30,
      "extend_s": 60,
      "instruction": "延续主歌旋律，加入弦乐"
    }'
  ```

  ```python Python theme={null}
  import requests

  url = "https://gccai.heqingsong.uk/v1/music/generations/extendFlowMusic"

  payload = {
      "model": "flowmusic",
      "clip_id": "abc123-def456",
      "extend_from_s": 30,
      "extend_s": 60,
      "instruction": "延续主歌旋律，加入弦乐"
  }

  headers = {
      "Authorization": "Bearer <token>",
      "Content-Type": "application/json"
  }

  response = requests.post(url, json=payload, headers=headers)

  print(response.json())
  ```

  ```javascript JavaScript theme={null}
  const url = "https://gccai.heqingsong.uk/v1/music/generations/extendFlowMusic";

  const payload = {
    model: "flowmusic",
    clip_id: "abc123-def456",
    extend_from_s: 30,
    extend_s: 60,
    instruction: "延续主歌旋律，加入弦乐"
  };

  const headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
  };

  fetch(url, {
    method: "POST",
    headers: headers,
    body: JSON.stringify(payload)
  })
    .then(response => response.json())
    .then(data => console.log(data))
    .catch(error => console.error('Error:', error));
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={null}
  {
    "code": 200,
    "data": [
      {
        "status": "submitted",
        "task_id": "task_01KWXVCYB70YJ1WY9X22RVYRNP"
      }
    ]
  }
  ```

  ```json 400 theme={null}
  {
    "error": {
      "message": "clip_id is required",
      "type": "invalid_request",
      "param": "",
      "code": "invalid_request"
    }
  }
  ```

  ```json 403 theme={null}
  {
    "error": {
      "message": "余额不足",
      "type": "invalid_request",
      "param": "",
      "code": "quota_not_enough"
    }
  }
  ```

  ```json 429 theme={null}
  {
    "error": {
      "message": "当前分组容量饱和，请稍后重试",
      "type": "rate_limit_error",
      "param": "",
      "code": "rate_limit_error"
    }
  }
  ```
</ResponseExample>

## 认证

<ParamField header="Authorization" type="string" required>
  所有接口均需要使用 Bearer Token 进行认证

  获取 API Key：

  访问 [API Key 管理页面](https://gccai.heqingsong.uk/keys) 获取您的 API Key

  使用时在请求头中添加：

  ```
  Authorization: Bearer YOUR_API_KEY
  ```
</ParamField>

## 请求参数

<ParamField body="model" type="string" required>
  模型名称，**固定传 `"flowmusic"`**（大小写不敏感）
</ParamField>

<ParamField body="clip_id" type="string" required>
  源音乐 clip\_id，来自已成功任务的 `result.music[].clip_id`

  <Note>
    源任务必须已成功。外部音频可先通过[上传音频](./upload-audio)导入换取 clip\_id。
  </Note>
</ParamField>

<ParamField body="extend_from_s" type="number" required>
  开始续写的时间点（秒）

  不能超过源 clip 时长
</ParamField>

<ParamField body="extend_s" type="number" required>
  续写时长（秒）

  最大值：`164` 秒
</ParamField>

<ParamField body="instruction" type="string" required>
  续写音乐的编辑指令

  示例：`"延续主歌旋律，加入弦乐"`
</ParamField>

<ParamField body="title" type="string">
  续写后音乐标题
</ParamField>

<ParamField body="seed" type="string">
  随机种子，用于复现结果
</ParamField>

## 响应

<ResponseField name="code" type="integer">
  响应状态码，成功时为 200
</ResponseField>

<ResponseField name="data" type="array">
  返回数据数组

  <Expandable title="数组元素">
    <ResponseField name="status" type="string">
      任务状态，初始提交时为 `submitted`
    </ResponseField>

    <ResponseField name="task_id" type="string">
      任务唯一标识符，用于查询任务状态和结果
    </ResponseField>
  </Expandable>
</ResponseField>

## 使用场景

### 场景 1：从副歌处续写 60 秒

```json theme={null}
{
  "model": "flowmusic",
  "clip_id": "abc123-def456",
  "extend_from_s": 30,
  "extend_s": 60,
  "instruction": "延续主歌旋律，加入弦乐"
}
```

<Note>
  **查询任务结果**

  音乐延伸为异步任务，提交后会返回 `task_id`。使用 [获取任务状态](./query) 接口查询生成进度和结果。延伸产物是**新的** `clip_id`，后续操作请使用新 clip\_id。
</Note>

## 任务完成结果示例

**查询返回示例**（`GET /v1/music/tasks/{task_id}`）：

```json theme={null}
{
  "code": 200,
  "data": {
    "id": "task_01KWXVCYB70YJ1WY9X22RVYRNP",
    "status": "completed",
    "progress": 100,
    "created": 1783413242,
    "completed": 1783413292,
    "actual_time": 50,
    "cost": 0.048,
    "credits_cost": 0.48,
    "result": {
      "music": [
        {
          "clip_id": "d2f589ea-5390-4e83-8e2f-4517420408fa",
          "title": "Untitled (Extended)",
          "duration_seconds": "39.95733333",
          "create_time": "2026-07-07T08:34:33.240020Z",
          "lyrics": "waking up to the morning light,\n...",
          "lyrics_id": "0452451b-9e54-5d9f-8437-8bff97c7bbc8",
          "lyrics_timing_markers": [[0, 12], [129, 20]],
          "audio_url": "https://gccai.heqingsong.uk/_gccai/cdn/audio/flowmusic_d2f589ea.m4a",
          "wav_url": "https://gccai.heqingsong.uk/_gccai/cdn/audio/flowmusic_d2f589ea.wav",
          "image_url": "https://gccai.heqingsong.uk/_gccai/cdn/image/flowmusic_d2f589ea_cover.jpg"
        }
      ]
    }
  }
}
```