Speech

Speech is an experimental feature.

The AI SDK provides the generateSpeech function to generate speech from text using a speech model.

import { experimental_generateSpeech as generateSpeech } from 'ai';
import { openai } from '@ai-sdk/openai';

const audio = await generateSpeech({
  model: openai.speech('tts-1'),
  text: 'Hello, world!',
  voice: 'alloy',
});

Language Setting

You can specify the language for speech generation (provider support varies):

import { experimental_generateSpeech as generateSpeech } from 'ai';
import { lmnt } from '@ai-sdk/lmnt';

const audio = await generateSpeech({
  model: lmnt.speech('aurora'),
  text: 'Hola, mundo!',
  language: 'es', // Spanish
});

To access the generated audio:

const audio = audio.audioData; // audio data e.g. Uint8Array

Settings

Provider-Specific settings

You can set model-specific settings with the providerOptions parameter.

import { experimental_generateSpeech as generateSpeech } from 'ai';
import { openai } from '@ai-sdk/openai';

const audio = await generateSpeech({
  model: openai.speech('tts-1'),
  text: 'Hello, world!',
  providerOptions: {
    openai: {
      // ...
    },
  },
});

Abort Signals and Timeouts

generateSpeech accepts an optional abortSignal parameter of type AbortSignal that you can use to abort the speech generation process or set a timeout.

import { openai } from '@ai-sdk/openai';
import { experimental_generateSpeech as generateSpeech } from 'ai';

const audio = await generateSpeech({
  model: openai.speech('tts-1'),
  text: 'Hello, world!',
  abortSignal: AbortSignal.timeout(1000), // Abort after 1 second
});

Custom Headers

generateSpeech accepts an optional headers parameter of type Record<string, string> that you can use to add custom headers to the speech generation request.

import { openai } from '@ai-sdk/openai';
import { experimental_generateSpeech as generateSpeech } from 'ai';

const audio = await generateSpeech({
  model: openai.speech('tts-1'),
  text: 'Hello, world!',
  headers: { 'X-Custom-Header': 'custom-value' },
});

Warnings

Warnings (e.g. unsupported parameters) are available on the warnings property.

import { openai } from '@ai-sdk/openai';
import { experimental_generateSpeech as generateSpeech } from 'ai';

const audio = await generateSpeech({
  model: openai.speech('tts-1'),
  text: 'Hello, world!',
});

const warnings = audio.warnings;

Error Handling

When generateSpeech cannot generate a valid audio, it throws a AI_NoSpeechGeneratedError.

This error can arise for any the following reasons:

The model failed to generate a response
The model generated a response that could not be parsed

The error preserves the following information to help you log the issue:

responses: Metadata about the speech model responses, including timestamp, model, and headers.
cause: The cause of the error. You can use this for more detailed error handling.

import {
  experimental_generateSpeech as generateSpeech,
  NoSpeechGeneratedError,
} from 'ai';
import { openai } from '@ai-sdk/openai';

try {
  await generateSpeech({
    model: openai.speech('tts-1'),
    text: 'Hello, world!',
  });
} catch (error) {
  if (NoSpeechGeneratedError.isInstance(error)) {
    console.log('AI_NoSpeechGeneratedError');
    console.log('Cause:', error.cause);
    console.log('Responses:', error.responses);
  }
}

Speech Models

Provider	Model
OpenAI	`tts-1`
OpenAI	`tts-1-hd`
OpenAI	`gpt-4o-mini-tts`
ElevenLabs	`eleven_v3`
ElevenLabs	`eleven_multilingual_v2`
ElevenLabs	`eleven_flash_v2_5`
ElevenLabs	`eleven_flash_v2`
ElevenLabs	`eleven_turbo_v2_5`
ElevenLabs	`eleven_turbo_v2`
LMNT	`aurora`
LMNT	`blizzard`
Hume	`default`

Above are a small subset of the speech models supported by the AI SDK providers. For more, see the respective provider documentation.