Piper

Overview

PiperTTSService provides high-quality neural text-to-speech synthesis through a self-hosted HTTP server. The service offers complete privacy and control with no external API dependencies, making it ideal for on-premise deployments and applications requiring data sovereignty.

Piper TTS API Reference

Pipecat’s API methods for Piper TTS integration

Example Implementation

Browse examples using Piper TTS

Piper Documentation

Official Piper TTS documentation and setup

HTTP Server Setup

Configure Piper HTTP server for Pipecat

Installation

To use Piper services, no additional Pipecat dependencies are required:

uv add "pipecat-ai"  # Base installation is sufficient

Prerequisites

Piper Server Setup

Before using PiperTTSService, you need:

Piper TTS Server: Set up a running Piper TTS server following the HTTP server documentation
Voice Models: Download and configure voice models for your target languages
Server Configuration: Configure server endpoint and voice selection

Required Configuration

Server URL: Configure the Piper server endpoint in your service initialization
Voice Models: Ensure required voice models are available on the server

Piper runs entirely locally, providing complete privacy and eliminating API key requirements.

Configuration

Piper offers two service implementations: PiperTTSService for local inference and PiperHttpTTSService for HTTP server-based synthesis.

PiperTTSService

Runs Piper locally, automatically downloading voice models as needed.

str

required

deprecated

Piper voice model identifier (e.g. en_US-ryan-high). Deprecated in v0.0.105. Use settings=PiperTTSService.Settings(voice=...) instead.

PiperTTSService.Settings

default:"None"

Runtime-configurable settings. See PiperTTSService Settings below.

Path

default:"None"

Directory for storing voice model files. Defaults to the current working directory.

bool

default:"False"

Re-download the voice model even if it already exists locally.

bool

default:"False"

Use CUDA for GPU-accelerated inference.

PiperTTSService Settings

Runtime-configurable settings passed via the settings constructor argument using PiperTTSService.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.)

PiperHttpTTSService

Connects to a running Piper HTTP TTS server.

str

required

Base URL for the Piper TTS HTTP server.

aiohttp.ClientSession

required

An aiohttp session for HTTP requests.

str

default:"None"

deprecated

Piper voice model identifier (e.g. en_US-ryan-high). Deprecated in v0.0.105. Use settings=PiperHttpTTSService.Settings(voice=...) instead.

PiperHttpTTSService.Settings

default:"None"

Runtime-configurable settings. See PiperHttpTTSService Settings below.

PiperHttpTTSService Settings

Runtime-configurable settings passed via the settings constructor argument using PiperHttpTTSService.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.)

Usage

Local Inference

from pipecat.services.piper import PiperTTSService

tts = PiperTTSService(
    settings=PiperTTSService.Settings(
        voice="en_US-ryan-high",
    ),
)

HTTP Server

Start the Piper HTTP server first:

uv add "piper-tts[http]"
uv run python -m piper.http_server -m en_US-ryan-high

Then connect to it:

import aiohttp
from pipecat.services.piper import PiperHttpTTSService

async with aiohttp.ClientSession() as session:
    tts = PiperHttpTTSService(
        base_url="http://localhost:5000",
        aiohttp_session=session,
        settings=PiperHttpTTSService.Settings(
            voice="en_US-ryan-high",
        ),
    )

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

Notes

Local execution: PiperTTSService runs entirely locally with no network requests. Voice models are automatically downloaded on first use.
GPU acceleration: Set use_cuda=True for GPU-accelerated inference with PiperTTSService (requires CUDA-compatible hardware).
Audio resampling: Audio output is automatically resampled to match the pipeline’s configured sample rate.
No API key required: Piper is open-source and runs locally, so no API credentials are needed.
GPL-3.0 license: PiperTTSService runs Piper in-process via the piper-tts package (the piper extra), which is GPL-3.0 licensed. Distributing an application that includes it may subject the application to the GPL’s source-disclosure terms. To keep Piper out of your application’s license scope, use PiperHttpTTSService instead, which talks to a separately installed Piper HTTP server.

Pipecat Server

Client SDKs

Pipecat Flows

Pipecat Cloud

CLI

Pipecat Context Hub

Overview

Piper TTS API Reference

Example Implementation

Piper Documentation

HTTP Server Setup

Installation

Prerequisites

Piper Server Setup

Required Configuration

Configuration

PiperTTSService

PiperTTSService Settings

PiperHttpTTSService

PiperHttpTTSService Settings

Usage

Local Inference

HTTP Server

Notes

​Overview

Piper TTS API Reference

Example Implementation

Piper Documentation

HTTP Server Setup

​Installation

​Prerequisites

​Piper Server Setup

​Required Configuration

​Configuration

​PiperTTSService

​PiperTTSService Settings

​PiperHttpTTSService

​PiperHttpTTSService Settings

​Usage

​Local Inference

​HTTP Server

​Notes

Overview

Installation

Prerequisites

Piper Server Setup

Required Configuration

Configuration

PiperTTSService

PiperTTSService Settings

PiperHttpTTSService

PiperHttpTTSService Settings

Usage

Local Inference

HTTP Server

Notes