# Volcengine Video-to-Video Lip Sync API

> Volcengine Video-to-Video Lip Sync — high-quality AI video generation.

- **Provider**: ByteDance
- **Model id**: `volcengine-video-to-video-lip-sync`
- **Modality**: video
- **Price**: 8.14 credits /sec

## Overview

Volcengine Video-to-Video Lip Sync is called in two steps: create a generation task, then poll the task until the result is ready.

## Authentication

All requests require a Bearer Token in the request header:

```
Authorization: Bearer YOUR_API_KEY
```

## Create Task

`POST https://you.bot/api/v1/generate`

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| modelId | string | Yes | Model id: `volcengine-video-to-video-lip-sync` |
| input | object | Yes | Input parameters object (see below) |
| callbackUrl | string | No | https URL we POST the finished task to. Signed with `X-Webhook-Signature` once you create a webhook signing key in Dashboard → Settings |

### input object parameters

| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| video_url | string | Yes | Video asset URL (image URL) |
| audio_url | string | Yes | Target pure vocal audio URL; used to drive video lip movements. (image URL) |
| mode | string | Yes | Service identifier (options: lite \| basic) (default: lite) |
| separate_vocal | boolean | No | Enable vocal separation to suppress background noise. (true/false) (default: false) |
| open_scenedet | boolean | No | Whether to enable scene segmentation and speaker identification. Supported only in Basic mode. (true/false) (default: false) |
| align_audio | boolean | No | Supported in lite mode. Whether to loop the video when the audio is longer than the video. (true/false) (default: true) |
| align_audio_reverse | boolean | No | Supported in lite mode. Loop the video in reverse. Requires Align Audio to be on — the call is refused otherwise. (true/false) (default: false) |
| templ_start_seconds | number | No | Supported in lite mode. Start time of the template video, in seconds. (default: 0) |

### Request example

```json
{
  "modelId": "volcengine-video-to-video-lip-sync",
  "input": {
    "video_url": "https://you.bot/examples/gemini-omni.mp4",
    "audio_url": "https://you.bot/examples/suno-v4-5.mp3",
    "mode": "lite",
    "separate_vocal": false,
    "open_scenedet": false,
    "align_audio": true,
    "align_audio_reverse": false,
    "templ_start_seconds": 0
  }
}
```

### Response example

```json
{
  "taskId": "281e5b0…f39b9",
  "creditsCharged": 40.7
}
```

## Query Task

`GET https://you.bot/api/v1/task/{taskId}?model=volcengine-video-to-video-lip-sync`

When `state` is `success`, the output is in `resultUrls`: `{ "state": "success", "resultUrls": [ ... ] }`. (Text models return inline in the create response.)

## Error Codes

| Code | Description |
|------|-------------|
| 200 | Request successful |
| 400 | Invalid request parameters |
| 401 | Authentication failed — check API Key |
| 402 | Insufficient account balance |
| 403 | IP not allowed for this key, or the key is restricted to other models |
| 404 | Task not found, or it has expired |
| 409 | Duplicate request — an identical submit arrived moments ago. Nothing was charged; retry is safe |
| 413 | Payload too large — see the character and file-size limits for this model |
| 429 | Rate limit exceeded — retry after the Retry-After header |
| 500 | Internal server error |
| 504 | Upstream timed out — nothing was delivered; retry is safe |