​
Overview

SarvamTTSService converts text to speech using Sarvam AI’s TTS API. It specializes in Indian languages and provides extensive voice customization options including pitch, pace, and loudness control.

​
Installation

To use SarvamTTSService, no additional dependencies are required.

You’ll also need to set up your Sarvam AI API key as an environment variable: SARVAM_API_KEY

​
Configuration

​
Constructor Parameters

​
api_key
str
required

Your Sarvam AI API subscription key

​
voice_id
str
default:"anushka"

Speaker voice identifier (e.g., “anushka”, “meera”, “abhilash”)

​
model
str
default:"bulbul:v2"

TTS model to use (“bulbul:v1” or “bulbul:v2”)

​
aiohttp_session
aiohttp.ClientSession
required

Shared aiohttp session for making HTTP requests

​
base_url
str
default:"https://api.sarvam.ai"

Sarvam AI API base URL

​
sample_rate
int
default:"None"

Audio sample rate in Hz (8000, 16000, 22050, 24000)

​
params
InputParams
default:"None"

Additional voice and preprocessing parameters

​
InputParams Configuration

​
language
Language
default:"Language.HI"

Target language for synthesis

​
pitch
float
default:"0.0"

Voice pitch adjustment (-0.75 to 0.75)

​
pace
float
default:"1.0"

Speech speed (0.3 to 3.0)

​
loudness
float
default:"1.0"

Audio volume (0.1 to 3.0)

​
enable_preprocessing
bool
default:"False"

Enable text normalization for mixed-language content

​
Input

The service accepts text input through its TTS pipeline with automatic WAV header stripping for clean PCM output.

​
Output Frames

​
TTSStartedFrame

Signals the start of audio generation.

​
TTSAudioRawFrame

Contains generated audio data:

​
audio
bytes

Raw PCM audio data (WAV header stripped)

​
sample_rate
int

Audio sample rate (22050Hz default)

​
num_channels
int

Number of audio channels (1 for mono)

​
TTSStoppedFrame

Signals the completion of audio generation.

​
Methods

See the TTS base class methods for additional functionality.

​
Language Support

Sarvam AI TTS supports the following Indian languages:

Language CodeDescriptionService Code
Language.BNBengalibn-IN
Language.ENEnglish (India)en-IN
Language.GUGujaratigu-IN
Language.HIHindihi-IN
Language.KNKannadakn-IN
Language.MLMalayalamml-IN
Language.MRMarathimr-IN
Language.OROdiaod-IN
Language.PAPunjabipa-IN
Language.TATamilta-IN
Language.TETelugute-IN

​
Voice Models

See the Sarvam docs for the latest information on available voices and models.

​
Usage Example

from pipecat.services.sarvam.tts import SarvamTTSService
from pipecat.transcriptions.language import Language
import aiohttp

# Configure service
async with aiohttp.ClientSession() as session:
    tts = SarvamTTSService(
        api_key="your-api-key",
        voice_id="anushka",
        model="bulbul:v2",
        aiohttp_session=session,
        params=SarvamTTSService.InputParams(
            language=Language.HI,
        )
    )

    # Use in pipeline
    pipeline = Pipeline([
        ...,
        llm,
        tts,
        transport.output(),
    ])

​
Frame Flow

​
Metrics Support

The service supports metrics collection:

  • Time to First Byte (TTFB)
  • TTS usage metrics
  • Processing duration

​
Audio Processing

  • Returns base64-encoded WAV audio from API
  • Supports multiple sample rates (8000, 16000, 22050, 24000 Hz)
  • Generates mono audio output
  • Handles HTTP-based synthesis

​
Notes

  • Requires valid Sarvam AI API subscription key
  • Specializes in Indian languages and voices
  • Uses HTTP POST requests for synthesis
  • Thread-safe HTTP session management required