Inworld AI: Realtime TTS-2

Name: Realtime TTS-2
Author: Inworld AI

inworld/inworld-tts-2

active tts 1 provider

Playground

Inworld's flagship text-to-speech model: 200+ languages and locales, natural-language steering with persistent bracketed instruction tags, word/character timestamps with phoneme and viseme detail, instant and professional voice cloning, and a reported 100 ms P90 server-side time to first audio byte.

AuthorInworld AI

Languages94 languages

VoicesLoading...

Statusactive

Quick start

Realtime TTS-2

Create an API key

Create API key

Make a request

Pick an SDK, request mode, and language. The model and provider route are already filled in.

ElevenLabs SDK streaming TTS

Routes the ElevenLabs SDK through allmodels and streams the audio response.

import { ElevenLabsClient } from "elevenlabs";

const client = new ElevenLabsClient({
  apiKey: process.env.ALLMODELS_API_KEY,
  baseUrl: "https://api.allmodels.io/el"
});

const stream = await client.textToSpeech.stream("voice_id", {
  text: "I'm sorry, Dave. I'm afraid I can't do that.",
  modelId: "inworld/inworld-tts-2",
  outputFormat: "mp3_44100_128"
}, {
  queryParams: {
    provider: {
      "only": [
        "inworld"
      ]
    }
  }
});

const reader = stream.getReader();
for (;;) {
  const { done, value } = await reader.read();
  if (done) break;
  // Write value to your response, file, or audio playback pipeline.
}

Pass provider parameters

Pass provider preferences through the compatible SDK request options when you want to pin a route to a provider.

{
  queryParams: {
    provider: {
      only: ["inworld"]
    }
  }
}

Providers

Different providers can host the same model. Choose one provider when you need a fixed backend, or let routing select among them.

ProviderSlugPer 1k charactersLatencyiModesUptime

Inworld AI 9 params

inworld

From $0.025

—

Synchronous · Streaming

Inworld AI

9 documented provider parameters for this route.

Pricing

ModeLanguagePer 1k characters

Realtime Any $0.025

Realtime Any $0.02

Realtime Any $0.0175

Realtime Any $0.015

Realtime Any $0.0125

Batch Any $0.02

Parameters

audioConfig.audioEncoding body · unknown · optional

Mapped from allmodels parameter "response_format".

audioConfig.bitRate body · unknown · optional

Mapped from allmodels parameter "bit_rate".

audioConfig.sampleRateHertz body · unknown · optional

Mapped from allmodels parameter "sample_rate".

audioConfig.speakingRate body · unknown · optional

Mapped from allmodels parameter "speed".

instruction body · unknown · optional

Mapped from allmodels parameter "instructions".

language body · unknown · optional

Mapped from allmodels parameter "language".

modelId body · unknown · optional

Mapped from allmodels parameter "model".

text body · unknown · optional

Mapped from allmodels parameter "input".

voiceId body · unknown · optional

Mapped from allmodels parameter "voice".

Supported languages

94 languages

Arabic ar

Chinese zh

Dutch nl

English en

French fr

German de

Hebrew he

Hindi hi

Italian it

Japanese ja

Korean ko

Polish pl

Portuguese pt

Russian ru

Spanish es

Afrikaans af

Albanian sq

Amharic am

Armenian hy

Assamese as

Azerbaijani az

Basque eu

Belarusian be

Bengali bn

Bulgarian bg

Burmese my

Cantonese yue

Catalan ca

Cebuano ceb

Croatian hr

Czech cs

Danish da

Eastern Yiddish yih

Egyptian Arabic arz

Estonian et

Filipino fil

Finnish fi

Galician gl

Garhwali gbm

Georgian ka

Greek el

Gujarati gu

Gulf Arabic afb

Haitian Creole ht

Hijazi Arabic acw

Hungarian hu

Icelandic is

Indonesian id

Javanese jv

Kannada kn

Kazakh kk

Konkani kok

Lao lo

Latvian lv

Libyan Arabic ayl

Lithuanian lt

Luxembourgish lb

Macedonian mk

Maithili mai

Malagasy mg

Malay ms

Malayalam ml

Marathi mr

Mongolian mn

Najdi Arabic ars

Nepali ne

Northern Uzbek uzn

Norwegian Bokmål nb

Norwegian Nynorsk nn

Odia or

Omani Arabic acx

Pashto ps

Persian fa

Piedmontese pms

Punjabi pa

Romanian ro

Serbian sr

Sindhi sd

Sinhala si

Slovak sk

Slovenian sl

Swahili sw

Swedish sv

Tamil ta

Telugu te

Thai th

Tunisian Arabic aeb

Turkish tr

Ukrainian uk

Urdu ur

Uzbek uz

Vietnamese vi

Võro vro

Welsh cy

Voices

Features

Text to speech

Generates spoken audio from text input.

text_to_speech

Streaming

HTTP chunked streaming (POST /tts/v1/voice:stream, newline-delimited JSON with base64 audio) and a bidirectional WebSocket API.

streaming

Async long-text synthesis

Async job API (POST /tts/v1/voice:synthesizeAsync) accepts up to 100,000 characters per job (On-Demand accounts capped at 10,000) and stitches the audio server-side; the sync and streaming APIs cap text at 2,000 characters.

async_long_text

Batch synthesis

Batch job API (POST /tts/v1/voice:synthesizeBatch, marked Preview) accepts up to 10,000 items of 100,000 characters each, capped at 10,000 characters per whole batch on On-Demand accounts, and is metered 20% below realtime synthesis on every plan.

batch

Word timestamps

timestampType=WORD returns timestampInfo.wordAlignment with per-token start and end times, and CHARACTER returns characterAlignment.

word_timestamps

Phoneme and viseme timing

WORD timestamps include phoneticDetails with IPA phone symbols, durations and viseme symbols for lip-sync.

visemes

Instant voice cloning

High-quality instant voice cloning (IVC) is supported.

instant_voice_cloning

Multilingual

200+ languages and locales, with cross-lingual synthesis and voice localization.

multilingual

Speaking rate control

audioConfig.speakingRate accepts 0.5-1.5 (1.0 = native speed).

speed_control

Non-verbal tags

Bracketed non-verbal sounds such as [laugh] and [sigh] work on both TTS-2 models.

non_verbal_tags

Synthesis context

synthesisContext.previousRequests supplies prior turns' text as context.

synthesis_context

Natural-language steering

Bracketed instruction tags and the request-level instruction field direct delivery, and a tag persists until changed or [reset].

instruction_steering

Delivery mode

deliveryMode (STABLE, BALANCED or CREATIVE) trades consistency against emotional range and defaults to BALANCED.

delivery_mode

Professional voice cloning

Professional Voice Cloning is documented as supported on inworld-tts-2 only.

professional_voice_cloning

Code

ElevenLabs SDK streaming TTS

Routes the ElevenLabs SDK through allmodels and streams the audio response.

import { ElevenLabsClient } from "elevenlabs";

const client = new ElevenLabsClient({
  apiKey: process.env.ALLMODELS_API_KEY,
  baseUrl: "https://api.allmodels.io/el"
});

const stream = await client.textToSpeech.stream("voice_id", {
  text: "I'm sorry, Dave. I'm afraid I can't do that.",
  modelId: "inworld/inworld-tts-2",
  outputFormat: "mp3_44100_128"
}, {
  queryParams: {
    provider: {
      "only": [
        "inworld"
      ]
    }
  }
});

const reader = stream.getReader();
for (;;) {
  const { done, value } = await reader.read();
  if (done) break;
  // Write value to your response, file, or audio playback pipeline.
}