Create or add a version to a voice design

Creates a new voice design (version 1) when voice_design_id is omitted. When voice_design_id is provided, adds a new version to the existing design instead. A design can have at most 50 versions.

POST /voice_designs

JavaScript

JavaScript

import Telnyx from 'telnyx';

const client = new Telnyx({
  apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
});

const voiceDesign = await client.voiceDesigns.create({
  prompt: 'Speak in a warm, friendly tone',
  text: 'Hello, welcome to our service.',
});

console.log(voiceDesign.data);

201

{
  "data": {
    "record_type": "voice_design",
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "name": "friendly-narrator",
    "version": 1,
    "text": "Hello, welcome.",
    "prompt": "Speak in a warm tone",
    "voice_sample_size": 48000,
    "version_created_at": "2024-01-01T00:00:00Z",
    "created_at": "2024-01-01T00:00:00Z",
    "updated_at": "2024-01-01T00:00:00Z",
    "provider": "Telnyx",
    "provider_supported_models": [
      "Qwen3TTS"
    ],
    "provider_voice_id": "550e8400-e29b-41d4-a716-446655440000"
  }
}

Body

application/json

Request body for creating a new voice design or adding a version to an existing one. Omit voice_design_id to create a new design; include it to add a new version.

text · string · required

Sample text to synthesize for this voice design.

prompt · string · required

Natural language description of the voice style, e.g. 'Speak in a warm, friendly tone with a slight British accent'.

name · string

Name for the voice design. Required when creating a new design (voice_design_id is not provided); ignored when adding a version. Cannot be a UUID.

Required string length: 1 - 255

voice_design_id · string<uuid>

ID of an existing voice design to add a new version to. When provided, a new version is created instead of a new design.

language · string · default: Auto

Language for synthesis. Supported values: Auto, Chinese, English, Japanese, Korean, German, French, Russian, Portuguese, Spanish, Italian. Defaults to Auto.

temperature · number<float>

Sampling temperature controlling randomness. Higher values produce more varied output. Default: 0.9.

Required range: 0 <= x <= 2

top_k · integer

Top-k sampling parameter — limits the token vocabulary considered at each step. Default: 50.

Required range: 1 <= x <= 1000

top_p · number<float>

Top-p (nucleus) sampling parameter — cumulative probability cutoff for token selection. Default: 1.0.

Required range: 0 <= x <= 1

repetition_penalty · number<float>

Repetition penalty to reduce repeated patterns in generated audio. Default: 1.05.

Required range: 1 <= x <= 2

max_new_tokens · integer

Maximum number of tokens to generate. Default: 2048.

Required range: 100 <= x <= 4096

provider · enum<string> · default: telnyx

Voice synthesis provider. telnyx uses the Qwen3TTS model; minimax uses the Minimax speech models. Case-insensitive. Defaults to telnyx.

Available options: telnyx, minimax, Telnyx, Minimax

Response

201

application/json

Voice design created or new version added successfully.

Response envelope for a single voice design with full version detail.

data · object

A voice design object with full version detail.

Show child attributes