> ## Documentation Index
> Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Inworld TTS provider

> Configure Inworld as a text-to-speech provider on Telnyx with Mini low-latency, Max high-quality, and TTS-2 latest-generation models, voice format strings, and language support.

**Voice format:** `inworld.<Model>.<VoiceId>`

**Models:**

* `inworld-tts-1.5-mini` (alias `Mini`) — faster, lower latency.
* `inworld-tts-1.5-max` (alias `Max`) — higher quality.
* `inworld-tts-2` (alias `TTS2`) — latest generation; supports the `delivery_mode` parameter.

Defaults to `inworld-tts-1.5-mini` if model omitted.

## Voice Samples

| Voice                  | Model | Gender | Sample                                                               |
| ---------------------- | ----- | ------ | -------------------------------------------------------------------- |
| `Inworld.Max.Hank`     | Max   | Male   | <audio controls src="/audio/tts-samples/inworld-max-hank.mp3" />     |
| `Inworld.Mini.Loretta` | Mini  | Female | <audio controls src="/audio/tts-samples/inworld-mini-loretta.mp3" /> |

***

## WebSocket

### Query Parameters

| Parameter      | Type    | Default | Description                              |
| -------------- | ------- | ------- | ---------------------------------------- |
| `audio_format` | string  | `mp3`   | `mp3`, `linear16`.                       |
| `sample_rate`  | integer | `24000` | 8000, 16000, 22050, 24000, 44100, 48000. |
| `language`     | string  | —       | BCP-47 language code.                    |

### Voice Settings

| Field           | Type    | Default | Description                                                             |
| --------------- | ------- | ------- | ----------------------------------------------------------------------- |
| `encoding`      | string  | `MP3`   | `MP3` or `LINEAR16`.                                                    |
| `sample_rate`   | integer | `24000` | Output sample rate in Hz.                                               |
| `language_code` | string  | —       | BCP-47. Overrides `language` query param.                               |
| `delivery_mode` | string  | —       | `STABLE`, `BALANCED`, or `CREATIVE`. Only supported by `inworld-tts-2`. |

```json theme={null}
{
  "text": " ",
  "voice_settings": {
    "encoding": "LINEAR16",
    "sample_rate": 16000
  }
}
```

## REST API

### Fields

| Field           | Type    | Default         | Description                                                             |
| --------------- | ------- | --------------- | ----------------------------------------------------------------------- |
| `encoding`      | string  | `MP3`           | `MP3` or `LINEAR16`.                                                    |
| `sample_rate`   | integer | `24000`         | Output sample rate in Hz.                                               |
| `language_code` | string  | —               | BCP-47 language code.                                                   |
| `delivery_mode` | string  | —               | `STABLE`, `BALANCED`, or `CREATIVE`. Only supported by `inworld-tts-2`. |
| `output_type`   | string  | `binary_output` | `binary_output`, `base64_output`, or `audio_id`.                        |

### Response

Default (`binary_output`): chunked audio bytes.

With `output_type: "base64_output"`: JSON with base64-encoded audio.

With `output_type: "audio_id"`: JSON with an `audio_url` for deferred retrieval.