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Overview

SarvamSTTService provides real-time speech recognition using Sarvam AI’s WebSocket API, supporting Indian language transcription with Voice Activity Detection (VAD) and multiple audio formats for high-accuracy speech recognition.

Sarvam STT API Reference

Pipecat’s API methods for Sarvam STT integration

Example Implementation

Complete example with interruption handling

Sarvam Documentation

Official Sarvam AI STT documentation and features

Sarvam AI Platform

Access API keys and speech models

Installation

To use Sarvam services, install the required dependency:

Prerequisites

Sarvam AI Account Setup

Before using Sarvam STT services, you need:
  1. Sarvam AI Account: Sign up at Sarvam AI
  2. API Key: Generate an API key from your account dashboard
  3. Model Access: Access to Saarika (STT) or Saaras (STT-Translate) models, including the saaras:v3 model with support for multiple modes (transcribe, translate, verbatim, translit, codemix)

Required Environment Variables

  • SARVAM_API_KEY: Your Sarvam AI API key for authentication

Configuration

SarvamSTTService

api_key
str
required
Sarvam API key for authentication.
model
str
default:"saaras:v3"
deprecated
Sarvam model to use. Allowed values: "saarika:v2.5" (standard STT), "saaras:v2.5" (STT-Translate, auto-detects language), "saaras:v3" (advanced, supports mode and fine-grained VAD). Deprecated in v0.0.105. Use settings=SarvamSTTService.Settings(...) instead.
sample_rate
int
default:"None"
Audio sample rate in Hz. Defaults to 16000 if not specified.
mode
Literal['transcribe', 'translate', 'verbatim', 'translit', 'codemix']
default:"None"
Mode of operation. Only applicable to models that support it (e.g., saaras:v3). Defaults to the model’s default mode.
input_audio_codec
str
default:"wav"
Audio codec/format of the input file.
params
SarvamSTTService.InputParams
default:"None"
deprecated
Configuration parameters for Sarvam STT service. Deprecated in v0.0.105. Use settings=SarvamSTTService.Settings(...) instead.
settings
SarvamSTTService.Settings
default:"None"
Runtime-configurable settings for the STT service. See Settings below.
keepalive_timeout
float
default:"None"
Seconds of no audio before sending silence to keep the connection alive. None disables keepalive.
ttfs_p99_latency
float
default:"SARVAM_TTFS_P99"
P99 latency from speech end to final transcript in seconds. Override for your deployment. See stt-benchmark.
keepalive_interval
float
default:"5.0"
Seconds between idle checks when keepalive is enabled.

Settings

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

Usage

Basic Setup

With Language and Model Configuration

With Server-Side VAD

Notes

  • Default model changed: As of this update, the default model is saaras:v3 (previously saarika:v2.5). Applications that relied on the previous default should set settings=SarvamSTTService.Settings(model="saarika:v2.5") explicitly.
  • Supported languages: Bengali (bn-IN), Gujarati (gu-IN), Hindi (hi-IN), Kannada (kn-IN), Malayalam (ml-IN), Marathi (mr-IN), Tamil (ta-IN), Telugu (te-IN), Punjabi (pa-IN), Odia (od-IN), English (en-IN), and Assamese (as-IN).
  • Model-specific parameter validation: The service validates that parameters are compatible with the selected model. For example, prompt is only supported with saaras:v2.5, language is not supported with saaras:v2.5 (which auto-detects language), and the fine-grained VAD parameters are only supported with saaras:v3.
  • Fine-grained VAD tuning (saaras:v3 only): The saaras:v3 model supports server-side VAD with 10 tuning parameters for speech detection thresholds, frame-count controls, pre-speech padding, interruption sensitivity, and initial-frame skipping. These parameters are only available with the saaras:v3 model.
  • VAD modes: When vad_signals=False (default), the service relies on Pipecat’s local VAD and flushes the server buffer on VADUserStoppedSpeakingFrame. When vad_signals=True, the service uses Sarvam’s server-side VAD and broadcasts speaking frames from the server.
The InputParams / params= pattern is deprecated as of v0.0.105. Use Settings / settings= instead. See the Service Settings guide for migration details.

Event Handlers

In addition to the standard service connection events (on_connected, on_disconnected, on_connection_error), Sarvam STT provides: