Speech Synthesis API

Updated: 2026-07-14

Overview

• Call speech synthesis with an API Key to convert text into audio.
• This endpoint creates and processes the task synchronously. On success, it returns taskId, targetAudioUrl, and audio-related information.
• The user identity is resolved from the API Key. Do not pass user ID, channel, or source fields.

Base URL

The examples in this document use:

https://video-translation.viitor.com

Authentication

All OpenAPI requests must include the API Key in the request header:

Authorization: Bearer vt_live_xxx

Notes:

• API Keys can be created in the console.
• The account must have an active plan that includes API access when creating and calling an API Key.
• The account must remain in VIP status when calling the API, otherwise the API returns a permission error.
• The full API Key is displayed only once after creation. Store it securely.

Common Response Structure

1. Text to Speech

Endpoint

• Request URL: https://video-translation.viitor.com/openapi/v1/speech-synthesis/textToSpeech
• Method: POST
• Content-Type: application/json
• Response structure: {code, message, data}

HTTP Headers

Request Body

emotion Enum

Parameter Rules

1. sourceText is required.
2. voiceName is required. You can get it from the OpenAPI timbre list endpoint.
3. The OpenAPI speech synthesis endpoint does not support translation synthesis. Do not pass targetLanguage.
4. format only supports wav, mp3, and pcm. It defaults to wav if omitted or invalid.
5. speed must be between 0.5 and 2.0. Default: 1.0.
6. loudnessLufs must be between -30 and -6.
7. emotion supports 0, 2, 3, 4, 5, and 6. Default: 0.

Successful data Fields

Request Example

curl -X POST "https://video-translation.viitor.com/openapi/v1/speech-synthesis/textToSpeech" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json;charset=UTF-8" \
  -H "Authorization: Bearer vt_live_xxx" \
  -d '{
    "sourceText": "Welcome to ViiTor AI.",
    "voiceName": "alloy",
    "emotion": 0,
    "speed": 1.0,
    "loudnessLufs": -18,
    "format": "mp3"
  }'

Successful Response Example

{
  "code": 0,
  "message": "OK",
  "data": {
    "userId": 123456,
    "taskId": "ViiTor_AI_50C7A13A74DC46D8B31EAEF3382895BA",
    "targetAudioUrl": "https://cdn.example.com/audio/result.mp3",
    "fileFormat": "mp3"
  }
}

Common Error Codes