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

# Kling Advanced Lip Sync

> Re-animate the facial movements of a source video to match text (TTS) or an existing audio file.

Advanced Lip Sync drives a person's lip movements in a video to match provided speech. It supports two input modes — synthesize speech from text, or supply your own audio file.

**This endpoint requires a `session_id`** obtained from the [Identify Face](/guides/model-api/kuaishou/kling-identify-face) step. Always call Identify Face first.

## Workflow overview

```
1. identify-face  →  session_id
2. advanced-lip-sync (session_id + speech input)  →  task_id
3. Poll GET /kling/v1/videos/advanced-lip-sync/{task_id}  →  video URL
```

## Input modes

### Text mode — built-in TTS

Provide `text`, `voice_id`, and `voice_language`. The platform synthesizes the audio using the specified voice and drives the lip movements.

<CodeGroup>
  ```bash cURL theme={null}
  curl https://www.anyfast.ai/kling/v1/videos/advanced-lip-sync \
    -H "Authorization: Bearer YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "input": {
        "session_id": "YOUR_SESSION_ID",
        "text": "Hello, welcome to my channel.",
        "voice_id": "girlfriend_1_cn",
        "voice_language": "en"
      }
    }'
  ```

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

  response = requests.post(
      "https://www.anyfast.ai/kling/v1/videos/advanced-lip-sync",
      headers={
          "Authorization": "Bearer YOUR_API_KEY",
          "Content-Type": "application/json"
      },
      json={
          "input": {
              "session_id": "YOUR_SESSION_ID",
              "text": "Hello, welcome to my channel.",
              "voice_id": "girlfriend_1_cn",
              "voice_language": "en"
          }
      }
  )
  task = response.json()
  print(f"Task ID: {task['task_id']}")
  ```
</CodeGroup>

### Audio mode — custom audio file

Provide `audio_url` to drive lip movements directly from an existing audio recording.

<CodeGroup>
  ```bash cURL theme={null}
  curl https://www.anyfast.ai/kling/v1/videos/advanced-lip-sync \
    -H "Authorization: Bearer YOUR_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{
      "input": {
        "session_id": "YOUR_SESSION_ID",
        "audio_url": "https://example.com/speech.mp3"
      }
    }'
  ```

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

  # Step 1: create task
  response = requests.post(
      "https://www.anyfast.ai/kling/v1/videos/advanced-lip-sync",
      headers={
          "Authorization": "Bearer YOUR_API_KEY",
          "Content-Type": "application/json"
      },
      json={
          "input": {
              "session_id": "YOUR_SESSION_ID",
              "audio_url": "https://example.com/speech.mp3"
          }
      }
  )
  task_id = response.json()["task_id"]

  # Step 2: poll for result
  while True:
      result = requests.get(
          f"https://www.anyfast.ai/kling/v1/videos/advanced-lip-sync/{task_id}",
          headers={"Authorization": "Bearer YOUR_API_KEY"}
      ).json()
      status = result["data"]["status"]
      print(f"Status: {status}")
      if status == "succeeded":
          print("Video URL:", result["data"]["data"]["task_result"]["videos"][0]["url"])
          break
      elif status == "failed":
          print("Failed:", result["data"].get("fail_reason"))
          break
      time.sleep(5)
  ```
</CodeGroup>

## Parameters

| Parameter              | Type   | Required   | Description                                                                                                                                                                         |
| ---------------------- | ------ | ---------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `input.session_id`     | string | Yes        | Session ID from the Identify Face step                                                                                                                                              |
| `input.face_image_url` | string | No         | Reference face image URL for identity consistency                                                                                                                                   |
| `input.text`           | string | Text mode  | Text for the character to speak                                                                                                                                                     |
| `input.voice_id`       | string | Text mode  | Voice ID for TTS synthesis. See the [Voice ID reference](https://docs.qingque.cn/s/home/eZQDvafJ4vXQkP8T9ZPvmye8S?identityId=2E1MlYrrPk4) for available voices with audio previews. |
| `input.voice_language` | string | Text mode  | Language code: `zh` or `en`                                                                                                                                                         |
| `input.audio_url`      | string | Audio mode | Public URL of an audio file                                                                                                                                                         |

## Polling

After the task is created, poll with `GET /kling/v1/videos/advanced-lip-sync/{task_id}` using the [Task Query](/guides/model-api/kuaishou/kling-task-query) endpoint. Status transitions: `queued` → `processing` → `succeeded` / `failed`.

On success, the video download URL is available in `data.data.task_result.videos[0].url`.

<Card title="Prerequisites: Identify Face" icon="user" href="/guides/model-api/kuaishou/kling-identify-face">
  You must call this first to obtain a session\_id.
</Card>

<Card title="Voice ID Reference" icon="volume" href="https://docs.qingque.cn/s/home/eZQDvafJ4vXQkP8T9ZPvmye8S?identityId=2E1MlYrrPk4">
  Browse all available voice IDs with audio previews to choose the right voice for your lip sync.
</Card>

<Card title="API Reference" icon="code" href="/api-reference/model-api/kuaishou/kling-lip-sync">
  View the interactive API playground for Kling Advanced Lip Sync.
</Card>

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