# OpenAI Text to Speech

OpenAI Text to Speech

## Endpoint and authentication

`POST https://api.tu-zi.com/v1/audio/speech`

Transport: json

Use an inference API key. Examples contain placeholders; read credentials from environment variables.

```http
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
```

## Body parameters

| Field | Type | Required | Description / constraints |
| --- | --- | --- | --- |
| model | string | Yes | Model identifier. |
| input | string | Yes | Text to synthesize as speech. |
| voice | string | Yes | Voice identifier. Form initial value (not an upstream default): "alloy" Values: "alloy", "echo", "fable", "onyx", "nova", "shimmer" |
| response_format | string | No | Audio output format. Form initial value (not an upstream default): "mp3" Values: "mp3", "wav", "opus", "aac", "flac", "pcm" |
| speed | number | No | Speech speed multiplier. Range in this definition: 0.25 ~ 4 |

## Minimal request example

```json
{
  "model": "YOUR_MODEL",
  "input": "Hello",
  "voice": "YOUR_SUPPORTED_VOICE"
}
```

## Before running

Replace https://api.tu-zi.com with this site origin (do not append /v1 twice), and YOUR_MODEL with the exact marketplace model ID. Install requests for Python; use Node.js 20+ and save JavaScript as .mjs. WebSocket samples list their own dependencies.

Create an inference key on the site and set API_KEY in the environment; replace YOUR_API_KEY in cURL. Prepare local input.png/input.wav files for upload examples.

Start with a minimal request, then read the result using the response fields below. For async APIs, a returned task ID requires polling; acceptance does not mean generation has finished.

## Code examples

### curl

```bash
curl --request POST 'https://api.tu-zi.com/v1/audio/speech' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "model": "YOUR_MODEL",
  "input": "Hello",
  "voice": "YOUR_SUPPORTED_VOICE"
}' \
  --output 'output.audio'
```

### python

```python
import json
import os
import requests

url = "https://api.tu-zi.com/v1/audio/speech"
headers = json.loads("{\"Authorization\":\"Bearer YOUR_API_KEY\",\"Content-Type\":\"application/json\"}")
headers["Authorization"] = "Bearer " + os.environ["API_KEY"]
payload = json.loads("{\"model\":\"YOUR_MODEL\",\"input\":\"Hello\",\"voice\":\"YOUR_SUPPORTED_VOICE\"}")
response = requests.request("POST", url, headers=headers, json=payload, timeout=120)
response.raise_for_status()
if "json" in response.headers.get("Content-Type", "").lower():
    raise RuntimeError("Expected binary content, received JSON: " + response.text)
with open("output.audio", "wb") as output:
    output.write(response.content)
```

### javascript

```javascript
import { writeFile } from 'node:fs/promises';
// Node.js 20+
const url = "https://api.tu-zi.com/v1/audio/speech";
const headers = {
  "Authorization": "Bearer YOUR_API_KEY",
  "Content-Type": "application/json"
};
headers.Authorization = 'Bearer ' + process.env.API_KEY;
const response = await fetch(url, { method: "POST", headers, body: JSON.stringify({
  "model": "YOUR_MODEL",
  "input": "Hello",
  "voice": "YOUR_SUPPORTED_VOICE"
}) });
if (!response.ok) throw new Error(await response.text());
if ((response.headers.get("content-type") || "").toLowerCase().includes("json")) throw new Error("Expected binary content, received JSON: " + await response.text());
await writeFile("output.audio", Buffer.from(await response.arrayBuffer()));
```

## Response fields

| Field | Type | Description / constraints |
| --- | --- | --- |
| response body | binary | Usually audio bytes; save according to response Content-Type. |

## Errors and retries

Check HTTP status and protocol-specific errors; do not mix error formats across protocols. For 401/403 check credentials and permissions, for 429 back off, and for 5xx check gateway/upstream status. Error bodies may contain error/message/code depending on the protocol.

Use bounded exponential backoff for reads. Do not blindly retry task creation, generation, or key mutations, to avoid duplicate billing or execution.

## Constraints

This page describes the base protocol. Use the selected model quick start for supported fields, enums, limits and asynchronous behavior. Replace YOUR_MODEL. Form initial values are not upstream defaults.

## Documentation source

Definition version: 1

Reviewed: 2026-11-02

Source: https://api.tu-zi.com/en/docs/api/reference-relay-audio-speech

Related protocol guide: https://api.tu-zi.com/docs/api/audio-realtime

This export contains documentation and examples only, without real credentials, account data or user requests.