YepAPI
AI Models

Grok Voice TTS 1.0

xAI's speech model — five built-in voices across 20+ languages with automatic language detection.

POST/v1/media/queue
$0.0317/1K chars

Overview

Grok Voice TTS 1.0 is xAI's text-to-speech model. It converts text into spoken audio across more than 20 languages and detects the input language automatically, so a multilingual corpus needs no per-request language tagging. Five built-in voices are available: Eve, Ara, Rex, Sal, and Leo.

PropertyValue
Model IDx-ai/grok-voice-tts-1.0
Aliasgrok-voice
Upstream Modelx-ai/grok-voice-tts-1.0
CategoryText to Speech
Languages20+ languages with automatic language detection
Outputmp3 (default) or pcm
Pricing$0.0317 per 1,000 characters

Usage

All media models use the async job queue. Submit a job, then poll for the result.

Step 1: Submit Job

const res = await fetch('https://api.yepapi.com/v1/media/queue', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'x-ai/grok-voice-tts-1.0',
    prompt: 'Your text to speak goes here.',
    options: { voice: 'eve' },
  }),
});
const { data } = await res.json();
// data.jobId — use this to poll for results
curl -X POST https://api.yepapi.com/v1/media/queue \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "x-ai/grok-voice-tts-1.0", "prompt": "Your text to speak goes here."}'

Step 2: Poll for Result

const status = await fetch(`https://api.yepapi.com/v1/media/status/${data.jobId}`, {
  headers: { 'x-api-key': 'YOUR_API_KEY' },
});
const { data: job } = await status.json();
// job.status — "pending" | "processing" | "completed" | "failed"
// job.result.audio — { mimeType, base64 } when completed
curl https://api.yepapi.com/v1/media/status/JOB_ID \
  -H "x-api-key: YOUR_API_KEY"

Write the audio to a file:

import { writeFileSync } from 'node:fs';

writeFileSync('speech.mp3', Buffer.from(job.result.audio.base64, 'base64'));

Request Body

ParameterTypeRequiredDescriptionDefault
modelstringYesx-ai/grok-voice-tts-1.0
promptstringYesThe text to speak (max 50,000 bytes)
options.voicestringNoVoice identifiereve
options.outputFormatstringNomp3 (default) or pcmmp3
options.speednumberNoPlayback speed multiplier. Honoured only by models that support it1.0

Voices

eve is used when options.voice is omitted. 5 voices available:

  • eve
  • ara
  • rex
  • sal
  • leo

Features

  • 20+ languages with automatic language detection
  • Five built-in voices
  • No per-request language tagging needed
  • Consistent voice identity across languages

Billing

Speech is billed on the length of the input text, in UTF-8 bytes — for English text one byte is one character. The cost is known before synthesis starts, so the balance check at submit time quotes the exact final charge. Jobs have a $0.01 minimum.

Under the Hood

Powered by OpenRouter's unified speech API.

On this page