LiveKit

LiveKit Agents is a framework for realtime voice AI over WebRTC, SIP, and streaming media. The Gradium plugin lets a LiveKit agent use Gradium for speech-to-text, text-to-speech, or both inside the same AgentSession.

Gradium TTS plugin

LiveKit’s guide to Gradium text-to-speech.

Gradium STT plugin

LiveKit’s guide to Gradium speech-to-text.

Plugin reference

Python API reference for livekit.plugins.gradium.

Gradium guide

End-to-end Gradium and LiveKit voice agent walkthrough.

Install

Install LiveKit Agents with the Gradium plugin extra:

pip install "livekit-agents[gradium]~=1.5"

Set the required credentials in your environment:

export LIVEKIT_URL=wss://your-project.livekit.cloud
export LIVEKIT_API_KEY=your-livekit-api-key
export LIVEKIT_API_SECRET=your-livekit-api-secret
export GRADIUM_API_KEY=gd_your_api_key_here

Basic agent session

Use gradium.STT() to transcribe user audio and gradium.TTS() to synthesize agent replies.

from livekit.agents import AgentSession
from livekit.plugins import gradium

session = AgentSession(
    stt=gradium.STT(),
    tts=gradium.TTS(
        voice_id="YTpq7expH9539ERJ",
    ),
    # ... llm, vad, tools, and other session options
)

You can also use only one side of Gradium. For example, keep an existing STT provider and use Gradium just for speech output:

session = AgentSession(
    tts=gradium.TTS(),
    # ... llm, stt, etc.
)

Configuration

Common Gradium options in LiveKit Agents:

Setting	Applies to	Description
`api_key`	STT, TTS	Gradium API key. Defaults to `GRADIUM_API_KEY`.
`model_endpoint`	STT, TTS	Gradium WebSocket endpoint. Defaults to `api.gradium.ai`; requests are automatically routed to the nearest regional cluster.
`model_name`	STT, TTS	Gradium model name. Defaults to `default`.
`voice_id`	TTS	Gradium voice ID for synthesized replies. Defaults to Emma.
`pronunciation_id`	TTS	Optional Gradium pronunciation dictionary ID.
`json_config`	TTS	Advanced TTS settings such as speed and rewrite rules.
`vad_threshold`	STT	Semantic VAD threshold for detecting when the user has finished speaking.
`vad_bucket`	STT	Semantic VAD timing bucket.

Custom pronunciation

Pass a Gradium pronunciation dictionary ID into the TTS plugin when an agent needs brand names, product names, or domain-specific terms spoken consistently.

tts = gradium.TTS(
    voice_id="YTpq7expH9539ERJ",
    pronunciation_id="pronunciation_dictionary_id",
)

For lower-level pronunciation and rewrite behavior, see Pronunciation Dictionaries and Voice Settings.

When to use LiveKit with Gradium

Realtime voice agents: run a complete STT, LLM, and TTS loop in AgentSession.
WebRTC applications: connect browser and mobile users to Gradium-powered speech through LiveKit rooms.
Telephony agents: use LiveKit SIP while keeping Gradium as the speech model layer.
Production deployments: deploy LiveKit agents with managed rooms, credentials, and worker processes.

Introduction

Agent Frameworks

Tools

Gradium TTS plugin

Gradium STT plugin

Plugin reference

Gradium guide

Install

Basic agent session

Configuration

Custom pronunciation

When to use LiveKit with Gradium

Gradium TTS plugin

Gradium STT plugin

Plugin reference

Gradium guide

​Install

​Basic agent session

​Configuration

​Custom pronunciation

​When to use LiveKit with Gradium

Install

Basic agent session

Configuration

Custom pronunciation

When to use LiveKit with Gradium