SLNG TTS plugin guide | LiveKit Documentation

Available inPython

Overview

SLNG is a third-party gateway that proxies TTS requests to underlying providers (such as Deepgram and Rime) through a unified API. The plugin streams synthesized audio over WebSocket and routes requests across regions using a single API key.

Installation

Install the plugin:

uv add "livekit-agents[slng]~=1.5"

Authentication

The SLNG plugin requires a SLNG API key. Sign up at slng.ai to get one.

Set SLNG_API_KEY in your .env file.

Usage

Use SLNG TTS in an AgentSession or as a standalone speech generator. For example, you can use this TTS in the Voice AI quickstart.

from livekit.plugins import slng

session = AgentSession(
   tts=slng.TTS(
      model="deepgram/aura:2",
      voice="aura-2-thalia-en",
   ),
   # ... llm, stt, etc.
)

Parameters

This section describes some of the available parameters. See the plugin reference for a complete list of all available parameters.

api_keystringEnv: SLNG_API_KEY

SLNG API key. Required if the environment variable isn't set.

modelstringDefault: deepgram/aura:2

The SLNG model identifier in <provider>/<model>[:variant] format. For a list of supported provider and model identifiers, see the SLNG documentation .

voicestring

The voice identifier to synthesize with. Valid values depend on the selected model and provider. For supported voices, see the SLNG documentation . When omitted, the gateway selects a provider-appropriate default.

slng_base_urlstringDefault: api.slng.ai

The SLNG gateway host. Override this only if you need to use a custom deployment.

region_overridestring | list[str]

Pin requests to one or more SLNG regions, as a single region code or a priority-ordered list. Sent to the gateway as the X-Region-Override header. For the supported region codes, see the SLNG documentation .

languagestringDefault: en

Language code for the input text. Supported values depend on the selected model.

speedfloatDefault: 1.0

Speed multiplier for the generated audio.

Additional resources

The following resources provide more information about using SLNG with LiveKit Agents.

Python package

The livekit-plugins-slng package on PyPI.

Plugin reference

Reference for the SLNG plugin.

GitHub repo

View the source or contribute to the LiveKit SLNG plugin.

SLNG docs

SLNG's full docs site.

Voice AI quickstart

Get started with LiveKit Agents and SLNG.

SLNG STT

Guide to the SLNG STT plugin with LiveKit Agents.