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.

NVIDIA Riva TTS API Reference

Pipecat’s API methods for NVIDIA Riva TTS integration

Example Implementation

Complete example with Riva NIM

NVIDIA Riva Documentation

Official NVIDIA Riva TTS documentation

NVIDIA Developer Portal

Access API keys and Riva services

Installation

To use NVIDIA Riva services, install the required dependencies:

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
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

api_key · str · required

NVIDIA API key for authentication.

server · str · default: "grpc.nvcf.nvidia.com:443"

gRPC server endpoint.

voice_id · str · default: "Magpie-Multilingual.EN-US.Aria" · deprecated

Voice model identifier.

Deprecated in v0.0.105. Use settings=NvidiaTTSService.Settings(...) instead.

sample_rate · int · default: "None"

Audio sample rate in Hz. When None, uses the pipeline’s configured sample rate.

model_function_map · dict

Dictionary containing function_id and model_name for the TTS model.

use_ssl · bool · default: "True"

Whether to use SSL for the NVIDIA Riva server connection.

params · InputParams · default: "None" · deprecated

Runtime-configurable synthesis settings. See InputParams below.

Deprecated in v0.0.105. Use settings=NvidiaTTSService.Settings(...) instead.

settings · NvidiaTTSService.Settings · default: "None"

Runtime-configurable settings. See Settings below.

Settings

Runtime-configurable settings passed via the settings constructor argument using NvidiaTTSService.Settings(...). These can be updated mid-conversation with TTSUpdateSettingsFrame. See 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

from pipecat.services.nvidia import NvidiaTTSService

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

With Custom Voice and Quality

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,
    ),
)

The InputParams / params= pattern is deprecated as of v0.0.105. Use Settings / settings= instead. See the Service Settings guide for migration details.

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.