> ## Documentation Index
> Fetch the complete documentation index at: https://daily-mb-reorg-api-reference-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# NVIDIA Riva

> Text-to-speech service implementation using NVIDIA Riva

## Overview

`NvidiaTTSService` provides high-quality text-to-speech synthesis through NVIDIA Riva's cloud-based AI models accessible via gRPC API. The service offers multilingual support, configurable quality settings, and streaming audio generation optimized for real-time applications.

<CardGroup cols={2}>
  <Card title="NVIDIA Riva TTS API Reference" icon="code" href="https://reference-server.pipecat.ai/en/latest/api/pipecat.services.riva.tts.html">
    Pipecat's API methods for NVIDIA Riva TTS integration
  </Card>

  <Card title="Example Implementation" icon="play" href="https://github.com/pipecat-ai/pipecat/blob/main/examples/voice/voice-nvidia.py">
    Complete example with Riva NIM
  </Card>

  <Card title="NVIDIA Riva Documentation" icon="book" href="https://docs.nvidia.com/deeplearning/riva/user-guide/docs/tts/tts-overview.html">
    Official NVIDIA Riva TTS documentation
  </Card>

  <Card title="NVIDIA Developer Portal" icon="microphone" href="https://developer.nvidia.com/">
    Access API keys and Riva services
  </Card>
</CardGroup>

## Installation

To use NVIDIA Riva services, install the required dependencies:

```bash theme={null}
pip install "pipecat-ai[nvidia]"
```

## Prerequisites

### NVIDIA Riva Setup

Before using Riva TTS services, you need:

1. **NVIDIA Developer Account**: Sign up at [NVIDIA Developer Portal](https://developer.nvidia.com/)
2. **API Key**: Generate an NVIDIA API key for Riva services
3. **Riva Access**: Ensure access to NVIDIA Riva TTS services

### Required Environment Variables

* `NVIDIA_API_KEY`: Your NVIDIA API key for authentication

## Configuration

### NvidiaTTSService

<ParamField path="api_key" type="str" required>
  NVIDIA API key for authentication.
</ParamField>

<ParamField path="server" type="str" default="grpc.nvcf.nvidia.com:443">
  gRPC server endpoint.
</ParamField>

<ParamField path="voice_id" type="str" default="Magpie-Multilingual.EN-US.Aria" deprecated>
  Voice model identifier.

  *Deprecated in v0.0.105. Use `settings=NvidiaTTSService.Settings(...)` instead.*
</ParamField>

<ParamField path="sample_rate" type="int" default="None">
  Audio sample rate in Hz. When `None`, uses the pipeline's configured sample
  rate.
</ParamField>

<ParamField path="model_function_map" type="dict" default="{&#x22;function_id&#x22;: &#x22;877104f7-e885-42b9-8de8-f6e4c6303969&#x22;, &#x22;model_name&#x22;: &#x22;magpie-tts-multilingual&#x22;}">
  Dictionary containing `function_id` and `model_name` for the TTS model.
</ParamField>

<ParamField path="use_ssl" type="bool" default="True">
  Whether to use SSL for the NVIDIA Riva server connection.
</ParamField>

<ParamField path="params" type="InputParams" default="None" deprecated>
  Runtime-configurable synthesis settings. See [InputParams](#inputparams)
  below.

  *Deprecated in v0.0.105. Use `settings=NvidiaTTSService.Settings(...)` instead.*
</ParamField>

<ParamField path="settings" type="NvidiaTTSService.Settings" default="None">
  Runtime-configurable settings. See [Settings](#settings) below.
</ParamField>

### Settings

Runtime-configurable settings passed via the `settings` constructor argument using `NvidiaTTSService.Settings(...)`. These can be updated mid-conversation with `TTSUpdateSettingsFrame`. See [Service Settings](/pipecat/fundamentals/service-settings) for details.

| Parameter  | Type              | Default     | Description                            |
| ---------- | ----------------- | ----------- | -------------------------------------- |
| `model`    | `str`             | `None`      | Model identifier. *(Inherited.)*       |
| `voice`    | `str`             | `None`      | Voice identifier. *(Inherited.)*       |
| `language` | `Language \| str` | `None`      | Language for synthesis. *(Inherited.)* |
| `quality`  | `int`             | `NOT_GIVEN` | Audio quality setting.                 |

## Usage

### Basic Setup

```python theme={null}
from pipecat.services.nvidia import NvidiaTTSService

tts = NvidiaTTSService(
    api_key=os.getenv("NVIDIA_API_KEY"),
)
```

### With Custom Voice and Quality

```python theme={null}
from pipecat.services.nvidia import NvidiaTTSService
from pipecat.transcriptions.language import Language

tts = NvidiaTTSService(
    api_key=os.getenv("NVIDIA_API_KEY"),
    model_function_map={
        "function_id": "877104f7-e885-42b9-8de8-f6e4c6303969",
        "model_name": "magpie-tts-multilingual",
    },
    settings=NvidiaTTSService.Settings(
        voice="Magpie-Multilingual.EN-US.Aria",
        language=Language.EN_US,
        quality=40,
    ),
)
```

<Tip>
  The `InputParams` / `params=` pattern is deprecated as of v0.0.105. Use
  `Settings` / `settings=` instead. See the [Service Settings
  guide](/pipecat/fundamentals/service-settings) for migration details.
</Tip>

## Notes

* **gRPC-based**: NVIDIA Riva uses gRPC (not HTTP or WebSocket) for communication with the TTS service.
* **Model cannot be changed after initialization**: The model and function ID must be set during construction via `model_function_map`. Calling `set_model()` after initialization will log a warning and have no effect.
* **SSL enabled by default**: The service connects to NVIDIA's cloud endpoint with SSL. Set `use_ssl=False` only for local or custom Riva deployments.
* **Blocking gRPC calls**: Audio generation uses `asyncio.to_thread` to avoid blocking the event loop, since the underlying Riva client uses synchronous gRPC calls.