# inworld/inworld-1.5-max/text-to-speech

> Inworld 1.5 Max delivers premium text-to-speech synthesis with 56+ multilingual voices, adjustable speaking rate, and high-fidelity natural-sounding audio output. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing.

## Overview

- **Endpoint**: `https://api.wavespeed.ai/api/v3/inworld/inworld-1.5-max/text-to-speech`
- **Polling/result URL**: `https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result`
- **Model ID**: `inworld/inworld-1.5-max/text-to-speech`
- **Category**: text-to-speech

## API Information

This model can be used via our HTTP API or more conveniently via our client libraries.
The API is asynchronous: submit a prediction, then poll its result URL until it completes.

### Input Schema

The API accepts the following input parameters:

- **`text`** (`string`, _required_):
  Styling instructions on how to synthesize the content in the text field.

- **`voice_id`** (`string`, _optional_):
  The voice to use for speech generation.
  - Default: `"Alex"`
  - Options: "Alex", "Ashley", "Craig", "Deborah", "Dennis", "Edward", "Elizabeth", "Hades", "Julia", "Pixie", "Mark", "Olivia", "Priya", "Ronald", "Sarah", "Shaun", "Theodore", "Timothy", "Wendy", "Dominus", "Hana", "Clive", "Carter", "Blake", "Luna", "Yichen", "Xiaoyin", "Xinyi", "Jing", "Erik", "Katrien", "Lennart", "Lore", "Alain", "Hélène", "Mathieu", "Étienne", "Johanna", "Josef", "Gianni", "Orietta", "Asuka", "Satoshi", "Hyunwoo", "Minji", "Seojun", "Yoona", "Szymon", "Wojciech", "Heitor", "Maitê", "Diego", "Lupita", "Miguel", "Rafael", "Svetlana", "Elena", "Dmitry", "Nikolai", "Riya", "Manoj", "Yael", "Oren", "Nour", "Omar"

- **`speaking_rate`** (`number`, _optional_):
  The speed of speaking.
  - Default: `1`
  - Range: `0.5` to `1.5`

- **`temperature`** (`number`, _optional_):
  The temperature to use for the generation. A higher value means more randomness in the output.
  - Default: `1`
  - Range: `0.7` to `1.5`



**Required Parameters Example**:

```json
{
  "text": "A clear example input"
}
```

**Full Example**:

```json
{
  "text": "A clear example input",
  "voice_id": "Alex",
  "speaking_rate": 1,
  "temperature": 1
}
```

### Result Data Schema

The `data` object returned by the API has the following fields:

- **`created_at`** (`string (date-time)`, _optional_):
  ISO timestamp of when the request was created (e.g., "2023-04-01T12:34:56.789Z").

- **`id`** (`string`, _optional_):
  Unique identifier for the prediction, the ID of the prediction to get.

- **`model`** (`string`, _optional_):
  Model ID used for the prediction.

- **`outputs`** (`array of string | object`, _optional_):
  Array of generated outputs (empty when status is not completed). Items are usually URL strings, but may be text strings or structured result objects, depending on the model.

- **`status`** (`string`, _optional_):
  Status of the task: created, processing, completed, or failed.

- **`urls`** (`object`, _optional_):
  Object containing related API endpoints.



**Example `data` Object**:

```json
{
  "created_at": "example",
  "id": "example",
  "model": "example",
  "outputs": [],
  "status": "example",
  "urls": {}
}
```

## Usage Examples

The examples use `jq` to read JSON. Set your API key first:

```bash
set -euo pipefail
export WAVESPEED_API_KEY="your-api-key"
```

### 1. Submit a prediction

```bash
REQUEST_BODY=$(cat <<'JSON'
{
  "text": "A clear example input"
}
JSON
)

SUBMIT_RESPONSE=$(curl --silent --show-error --fail-with-body \
  --request POST \
  --url https://api.wavespeed.ai/api/v3/inworld/inworld-1.5-max/text-to-speech \
  --header "Authorization: Bearer ${WAVESPEED_API_KEY}" \
  --header "Content-Type: application/json" \
  --data "${REQUEST_BODY}")

printf '%s\n' "${SUBMIT_RESPONSE}" | jq .
```

The response contains the prediction ID in `data.id`.

### 2. Poll until complete and read `outputs`

```bash
PREDICTION_ID=$(printf '%s' "${SUBMIT_RESPONSE}" | jq -r '.data.id')
if [ -z "${PREDICTION_ID}" ] || [ "${PREDICTION_ID}" = "null" ]; then
  printf 'Submission response did not contain data.id\n' >&2
  exit 1
fi
RESULT_URL="https://api.wavespeed.ai/api/v3/predictions/${PREDICTION_ID}/result"

while true; do
  RESPONSE=$(curl --silent --show-error --fail-with-body \
    --request GET \
    --url "${RESULT_URL}" \
    --header "Authorization: Bearer ${WAVESPEED_API_KEY}")

  RESULT=$(printf '%s' "${RESPONSE}" | jq -e '.data')
  STATUS=$(printf '%s' "${RESULT}" | jq -er '.status')
  case "${STATUS}" in
    completed)
      # Generated files are returned in the outputs array.
      printf '%s\n' "${RESULT}" | jq '.outputs'
      break
      ;;
    failed|cancelled|timeout|deleted)
      printf '%s\n' "${RESULT}" | jq '{status, error, code}'
      exit 1
      ;;
    *)
      sleep 2
      ;;
  esac
done
```

## Additional Resources

### Documentation

- [Model Playground](https://wavespeed.ai/models/inworld/inworld-1.5-max/text-to-speech)
- [API Documentation](https://wavespeed.ai/docs/docs-api/inworld/inworld-inworld-1.5-max-text-to-speech)