Vartaloop Text-to-Speech

Community-maintained integration. This service is built and maintained by Vartaloop. Pipecat does not test or officially support it. Please report issues and request changes on the source repository. Learn more about community integrations.

Overview

VartaloopTTSService generates Hinglish and Indian-language speech from Vartaloop over one WebSocket per session, sending each sentence as its own utterance as soon as it is aggregated. VartaloopHttpTTSService does the same with one HTTP request per sentence.

Source Repository

Source code, tests, and issues for the Vartaloop integration

Example

A Hinglish voice agent using VartaloopTTSService

Vartaloop Docs

Voices, text normalisation, and the API reference

Installation

This is a community-maintained package distributed separately from pipecat-ai:

uv add "pipecat-vartaloop @ git+https://github.com/vartalaap-si/pipecat-vartaloop.git@v0.1.0"

Prerequisites

Vartaloop account: sign up at tts.vartaloop.ai.
API key: create one in the portal.

Required Environment Variables

VARTALOOP_API_KEY: your Vartaloop API key

Configuration

VartaloopTTSService

str | None

default:"None"

Vartaloop API key. When None, it is read from VARTALOOP_API_KEY. Raises ValueError when neither is set.

str

default:"wss://api.vartaloop.ai/v1/tts/stream"

WebSocket endpoint.

int | None

default:"None"

Output sample rate in Hz. When None, the pipeline’s rate is used. The API produces 24 kHz audio, which is resampled when the rates differ.

VartaloopTTSService.Settings | None

default:"None"

Runtime-configurable settings. See Settings.

VartaloopHttpTTSService

Takes api_key, sample_rate, and settings as above, plus:

aiohttp.ClientSession | None

default:"None"

HTTP session to reuse. When None, the service creates one.

str

default:"https://api.vartaloop.ai"

API base URL.

Settings

Both services take VartaloopTTSService.Settings. Every field can be changed with TTSUpdateSettingsFrame and applies from the next sentence, without reconnecting.

Field	Type	Default	Description
`voice`	`str`	`"saanvi"`	Voice id. The voice sets the language. See the Vartaloop docs for the voice list.
`expression`	`str`	`"neutral"`	Delivery: `"neutral"`, `"excited"`, `"sad"`, or `"whisper"`. A voice without the expression plays neutral. Alias: `style`.
`digits`	`str`	`"auto"`	How digits are read in Hinglish text: `"auto"`, `"hi"` (Hindi number words), `"mixed"` (codes in English, amounts in Hindi), or `"en"`.
`speed`	`float \| None`	`None`	Speaking pace from 0.5 to 2.0, pitch preserved. `None` keeps the voice’s own pace. Alias: `pace`.
`temperature`	`float \| None`	`None`	Sampling temperature from 0 to 2. `None` uses the server default.
`seed`	`int \| None`	`None`	Fixed sampling seed for reproducible audio.
`postfx`	`bool \| None`	`None`	Server-side loudness normalisation, high-pass, and limiter. `None` uses the server default.
`profile`	`str \| None`	`None`	`"default"` or `"telephony"`, which shapes audio for 8 kHz phone calls.
`raw`	`bool`	`False`	Skip the server’s text normaliser, for text that is already normalised.

Usage

Speak in a Voice Agent

Add the service to a pipeline after the LLM:

import os

from pipecat.pipeline.pipeline import Pipeline
from pipecat_vartaloop import VartaloopTTSService

tts = VartaloopTTSService(
    api_key=os.getenv("VARTALOOP_API_KEY"),
    settings=VartaloopTTSService.Settings(voice="saanvi", digits="mixed"),
)

pipeline = Pipeline(
    [
        transport.input(),
        stt,
        user_aggregator,
        llm,
        tts,
        transport.output(),
        assistant_aggregator,
    ]
)

Change the Expression Mid-Call

Push a TTSUpdateSettingsFrame:

from pipecat.frames.frames import TTSUpdateSettingsFrame

await task.queue_frame(
    TTSUpdateSettingsFrame(
        delta=VartaloopTTSService.Settings(expression="excited")
    )
)

Notes

Interruptions: VartaloopTTSService drops the interrupted turn’s audio and reopens its WebSocket, so the server stops synthesising it. Use it for conversational agents, and VartaloopHttpTTSService for pipelines without interruptions.
Compatibility: tested with Pipecat 1.15.

Get Started

Standards

Pipecat Server

Client SDKs

Pipecat Flows

Pipecat Cloud

CLI

Pipecat Context Hub

Vartaloop Text-to-Speech

Overview

Source Repository

Example

Vartaloop Docs

Installation

Prerequisites

Required Environment Variables

Configuration

VartaloopTTSService

VartaloopHttpTTSService

Settings

Usage

Speak in a Voice Agent

Change the Expression Mid-Call

Notes

​Overview

Source Repository

Example

Vartaloop Docs

​Installation

​Prerequisites

​Required Environment Variables

​Configuration

​VartaloopTTSService

​VartaloopHttpTTSService

​Settings

​Usage

​Speak in a Voice Agent

​Change the Expression Mid-Call

​Notes

Overview

Installation

Prerequisites

Required Environment Variables

Configuration

VartaloopTTSService

VartaloopHttpTTSService

Settings

Usage

Speak in a Voice Agent

Change the Expression Mid-Call

Notes