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Overview

NVIDIA Riva provides two STT service implementations:
  • NvidiaSTTService — Real-time streaming transcription using Parakeet models with interim results and continuous audio processing.
  • NvidiaSegmentedSTTService — Segmented transcription using Canary models with advanced language support, word boosting, and enterprise-grade accuracy.

NVIDIA Riva STT API Reference

Pipecat’s API methods for NVIDIA Riva STT integration

Example Implementation

Complete example with NVIDIA services integration

NVIDIA Riva Documentation

Official NVIDIA Riva ASR documentation

NVIDIA Developer Portal

Access API keys and Riva services

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Installation

To use NVIDIA Riva services, install the required dependency:

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Prerequisites

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NVIDIA Riva Setup

Before using NVIDIA Riva STT 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. Model Selection: Choose between Parakeet (streaming) and Canary (segmented) models

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Required Environment Variables

  • NVIDIA_API_KEY: Your NVIDIA API key for authentication

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NvidiaSTTService

Real-time streaming transcription using NVIDIA Riva’s Parakeet models.
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str
required
NVIDIA API key for authentication.
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str
default:"grpc.nvcf.nvidia.com:443"
NVIDIA Riva server address.
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Mapping[str, str]
Mapping containing function_id and model_name for the ASR model.
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int
default:"None"
Audio sample rate in Hz. When None, uses the pipeline’s configured sample rate.
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NvidiaSTTService.InputParams
default:"None"
deprecated
Additional configuration parameters. Deprecated in v0.0.105. Use settings=NvidiaSTTService.Settings(...) instead.
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NvidiaSTTService.Settings
default:"None"
Runtime-configurable settings. See Settings below.
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bool
default:"True"
Whether to use SSL for the gRPC connection.
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float
default:"1.0"
P99 latency from speech end to final transcript in seconds. Override for your deployment. See stt-benchmark.

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Settings

Runtime-configurable settings passed via the settings constructor argument using NvidiaSTTService.Settings(...). These can be updated mid-conversation with STTUpdateSettingsFrame. See Service Settings for details.

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Usage

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Notes

  • Model cannot be changed after initialization: Use the model_function_map parameter in the constructor to specify the model and function ID.
  • Streaming: Provides real-time interim and final results through continuous audio streaming.

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NvidiaSegmentedSTTService

Batch/segmented transcription using NVIDIA Riva’s Canary models. Processes complete audio segments after VAD detects speech boundaries.
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str
required
NVIDIA API key for authentication.
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str
default:"grpc.nvcf.nvidia.com:443"
NVIDIA Riva server address.
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Mapping[str, str]
Mapping containing function_id and model_name for the ASR model.
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int
default:"None"
Audio sample rate in Hz. When None, uses the pipeline’s configured sample rate.
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NvidiaSegmentedSTTService.InputParams
default:"None"
deprecated
Additional configuration parameters. Deprecated in v0.0.105. Use settings=NvidiaSegmentedSTTService.Settings(...) instead.
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NvidiaSegmentedSTTService.Settings
default:"None"
Runtime-configurable settings. See Settings below.
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bool
default:"True"
Whether to use SSL for the gRPC connection.
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float
default:"1.0"
P99 latency from speech end to final transcript in seconds. Override for your deployment. See stt-benchmark.

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Settings

Runtime-configurable settings passed via the settings constructor argument using NvidiaSegmentedSTTService.Settings(...). These can be updated mid-conversation with STTUpdateSettingsFrame. See Service Settings for details.

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Usage

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Notes

  • Model cannot be changed after initialization: Use the model_function_map parameter in the constructor to specify the model and function ID.
  • Segmented processing: Processes complete audio segments for higher accuracy compared to streaming.
  • Language support: Supports Arabic, English (US/GB), French, German, Hindi, Italian, Japanese, Korean, Portuguese (BR), Russian, and Spanish (ES/US).
  • Word boosting: Use boosted_lm_words and boosted_lm_score to improve recognition of domain-specific terms.
The InputParams / params= pattern is deprecated as of v0.0.105. Use Settings / settings= instead. See the Service Settings guide for migration details.