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

# TTS

> Text-to-speech endpoints

## Overview

Text-to-speech endpoints

### Available Operations

* [create\_speech](#create_speech) - Create speech

## create\_speech

Synthesizes audio from the input text. Returns a raw audio bytestream in the requested format (e.g. mp3, pcm, wav).

### Example Usage

```python theme={null}
from openrouter import OpenRouter
import os


with OpenRouter(
    http_referer="<value>",
    x_open_router_title="<value>",
    x_open_router_categories="<value>",
    api_key=os.getenv("OPENROUTER_API_KEY", ""),
) as open_router:

    res = open_router.tts.create_speech(input="Hello world", model="mistralai/voxtral-mini-tts-2603", response_format="pcm", speed=1, voice="en_paul_neutral")

    # Handle response
    print(res)

```

### Parameters

| Parameter | Type | Required | Description | Example |
| - | - | - | - | - |
| `input` | *str* | :heavy\_check\_mark: | Text to synthesize | Hello world |
| `model` | *str* | :heavy\_check\_mark: | TTS model identifier | mistralai/voxtral-mini-tts-2603 |
| `http_referer` | *Optional\[str]* | :heavy\_minus\_sign: | The app identifier should be your app's URL and is used as the primary identifier for rankings.<br />This is used to track API usage per application.<br /> | |
| `x_open_router_title` | *Optional\[str]* | :heavy\_minus\_sign: | The app display name allows you to customize how your app appears in OpenRouter's dashboard.<br /> | |
| `x_open_router_categories` | *Optional\[str]* | :heavy\_minus\_sign: | Comma-separated list of app categories (e.g. "cli-agent,cloud-agent"). Used for marketplace rankings.<br /> | |
| `input_references` | List\[[components.SpeechInputReference](../../components/speechinputreference.mdx)] | :heavy\_minus\_sign: | Reference content for stateless voice cloning or voice design. Audio mode: one to three `input_audio` parts, each optionally paired with a `text` part carrying its transcript (a single clip accepts its transcript before or after it; with multiple clips each transcript immediately follows its clip); only routed to endpoints that support voice cloning (and multiple references when more than one part is sent). Image mode: exactly one `image_url` part; only routed to endpoints that support image references. The two modes cannot be mixed. An empty array is treated as no reference. | \[<br />\{<br />"input\_audio": \{<br />"data": "data:audio/wav;base64,UklGRuQXDABXQVZF..."<br />},<br />"type": "input\_audio"<br />},<br />\{<br />"text": "I used to rule the world.",<br />"type": "text"<br />}<br />] |
| `provider` | [Optional\[components.SpeechRequestProvider\]](../../components/speechrequestprovider.mdx) | :heavy\_minus\_sign: | Provider-specific passthrough configuration | |
| `response_format` | [Optional\[components.SpeechRequestResponseFormat\]](../../components/speechrequestresponseformat.mdx) | :heavy\_minus\_sign: | Audio output format | pcm |
| `session_id` | *Optional\[str]* | :heavy\_minus\_sign: | A unique identifier for grouping related requests (e.g., a conversation or agent workflow). Used for observability grouping in Broadcast and private logging; never sent to the provider. If provided in both the request body and the x-session-id header, the body value takes precedence. Maximum of 256 characters. | session-1234 |
| `speed` | *Optional\[float]* | :heavy\_minus\_sign: | Playback speed multiplier. Only used by models that support it (e.g. OpenAI TTS). Ignored by other providers. | 1 |
| `trace` | [Optional\[components.TraceConfig\]](../../components/traceconfig.mdx) | :heavy\_minus\_sign: | Metadata for observability and tracing. Known keys (trace\_id, trace\_name, span\_name, generation\_name, parent\_span\_id) have special handling. Additional keys are passed through as custom metadata to configured broadcast destinations. | \{<br />"trace\_id": "trace-abc123",<br />"trace\_name": "my-app-trace"<br />} |
| `user` | *Optional\[str]* | :heavy\_minus\_sign: | A unique identifier representing your end-user. Forwarded to Broadcast and private logging as the end-user id; never sent to the provider. | user-1234 |
| `voice` | *Optional\[str]* | :heavy\_minus\_sign: | Voice identifier (provider-specific). | en\_paul\_neutral |
| `retries` | [Optional\[utils.RetryConfig\]](../../models/utils/retryconfig.mdx) | :heavy\_minus\_sign: | Configuration to override the default retry behavior of the client. | |

### Response

**[httpx.Response](../../models/.mdx)**

### Errors

| Error Type | Status Code | Content Type |
| - | - | - |
| errors.BadRequestResponseError | 400 | application/json |
| errors.UnauthorizedResponseError | 401 | application/json |
| errors.PaymentRequiredResponseError | 402 | application/json |
| errors.ForbiddenResponseError | 403 | application/json |
| errors.NotFoundResponseError | 404 | application/json |
| errors.PayloadTooLargeResponseError | 413 | application/json |
| errors.TooManyRequestsResponseError | 429 | application/json |
| errors.InternalServerResponseError | 500 | application/json |
| errors.BadGatewayResponseError | 502 | application/json |
| errors.ServiceUnavailableResponseError | 503 | application/json |
| errors.EdgeNetworkTimeoutResponseError | 524 | application/json |
| errors.ProviderOverloadedResponseError | 529 | application/json |
| errors.OpenRouterDefaultError | 4XX, 5XX | \*/\* |