Voice Creation

Every text-to-speech provider ships a fixed catalog of voices. Your narrator, your character, or your brand can be absent from that catalog. generateVoice() makes a new voice instead of picking one.

There are two ways to create a voice:

• Design: you describe the voice in words. The provider invents it.
• Clone: you supply a clip of a real speaker, and the provider derives a voice from it.

Both give you a voice ID. Pass that ID to generateSpeech() as the voice option.

Design a voice from a description

Describe the voice you want. The provider returns candidate voices, each with a short preview you can listen to.

import { generateVoice } from '@tanstack/ai'
import { elevenlabsVoiceDesign } from '@tanstack/ai-elevenlabs'

const result = await generateVoice({
  adapter: elevenlabsVoiceDesign('eleven_ttv_v3'),
  prompt: 'A warm, gravelly narrator in his sixties with a slight Irish lilt',
})

for (const voice of result.voices) {
  console.log(voice.voiceId) // Pass this to generateSpeech()
  console.log(voice.audio) // Base64 preview audio
}

A longer, more specific description gives a better result. Name the age, the accent, the pace, and the mood.

Speak with the new voice

The voice ID goes straight into generateSpeech().

import { generateSpeech, generateVoice } from '@tanstack/ai'
import { elevenlabsSpeech, elevenlabsVoiceDesign } from '@tanstack/ai-elevenlabs'

const designed = await generateVoice({
  adapter: elevenlabsVoiceDesign('eleven_ttv_v3'),
  prompt: 'A warm, gravelly narrator in his sixties',
})

const [best] = designed.voices
if (!best) throw new Error('The provider returned no voices.')

const speech = await generateSpeech({
  adapter: elevenlabsSpeech('eleven_v4'),
  text: 'Once upon a time, in a village at the edge of the sea...',
  voice: best.voiceId,
})

console.log(speech.contentType) // 'audio/mpeg'

Keep a voice for later

A designed voice is a preview by default. Previews expire. To keep a voice in the provider's library, pass a name.

import { generateVoice } from '@tanstack/ai'
import { elevenlabsVoiceDesign } from '@tanstack/ai-elevenlabs'

const result = await generateVoice({
  adapter: elevenlabsVoiceDesign('eleven_ttv_v3'),
  prompt: 'A bright, upbeat product demo host',
  name: 'Demo Host',
  description: 'Bright, upbeat, mid-30s',
})

const [saved] = result.voices
if (!saved) throw new Error('The provider returned no voices.')

console.log(saved.saved) // true
console.log(saved.voiceId) // A permanent voice ID. Store it.

Store voiceId in your database. Every later generateSpeech() call reuses it, and you never design the same voice twice.

Providers differ on what name means. ElevenLabs keeps a voice only when you give a name. Read saved on each returned voice to see what happened.

Guide a design with reference audio

Some models take a clip of a real speaker as a reference. Pass the audio as referenceAudio.

ElevenLabs is a design-with-reference, not a straight copy: eleven_ttv_v3 still needs a prompt, and modelOptions.promptStrength sets how much of the result comes from the description rather than the clip. Pass 0 for a result that leans almost entirely on the reference.

import { readFile } from 'node:fs/promises'
import { generateVoice } from '@tanstack/ai'
import { elevenlabsVoiceDesign } from '@tanstack/ai-elevenlabs'

const clip = await readFile('./narrator.mp3')

const result = await generateVoice({
  adapter: elevenlabsVoiceDesign('eleven_ttv_v3'),
  prompt: 'The same speaker, but younger and more energetic',
  // `new Blob([clip])`, not `clip.buffer`: a Buffer can be a view into a
  // shared pool, so its `.buffer` is not necessarily just the file's bytes.
  referenceAudio: new Blob([clip]),
  name: 'Young Narrator',
})

referenceAudio accepts a base64 string, a base64 data URL, a Blob, a File, or an ArrayBuffer. A remote URL is refused: read the file yourself and pass the bytes.

CAUTION: Clone a voice only with the consent of the speaker. Most providers make this a condition of their terms.

Find a voice you made earlier

Store the voiceId and you never need this. If you lose it, listVoices() reads the account's catalog back.

import { listVoices } from '@tanstack/ai'
import { elevenlabsSpeech } from '@tanstack/ai-elevenlabs'

const { voices } = await listVoices({
  adapter: elevenlabsSpeech('eleven_v4'),
  origins: ['generated', 'cloned'],
})

for (const voice of voices) {
  console.log(voice.voiceId, voice.name)
}

Each voice carries voiceId, and name, origin, description, previewUrl and labels when the provider reports them. origin is one of:

• premade: the provider's stock catalog.
• generated: designed from a description.
• cloned: made from reference audio.
• professional: a curated or paid tier.

Leave origins off to get everything, including the stock voices.

Only providers with a per-account catalog implement this. Where the voice list is fixed, the provider package publishes it instead, which is better than a network call: use GeminiTTSVoices from @tanstack/ai-gemini, or the OpenAITTSVoice union from @tanstack/ai-openai. listVoices() throws on those adapters, and the message points at those exports.

Provider support

ElevenLabs is the only provider with a generateVoice() adapter today.

Providers such as OpenAI, Gemini, and Cloudflare have a fixed voice catalog. They have no generateVoice() adapter, and they will not get one.

xAI, BytePlus, and fal.ai each publish a voice-cloning API, so they are the candidates for the next adapter. None is implemented here yet, and this page will describe them once one is.

Options

You must give prompt, or referenceAudio, or both. ElevenLabs always needs prompt, because its design endpoint requires a description.

Each returned voice carries voiceId, saved, and status, plus audio, format, contentType, duration, and language when the provider reports them. status is 'ready' on every adapter today, because they all finish the voice before returning.

Next steps

• Text-to-Speech: speak with the voice you made.
• ElevenLabs adapter: model IDs and provider options.