LemonSlice Avatar Plugin for Vision Agents

Add real-time interactive avatar video to your AI agents using LemonSlice's self-managed API.

Features

• Real-time avatar video synchronized with TTS audio
• Works with any TTS provider (Cartesia, ElevenLabs, etc.)
• Supports both standard and Realtime LLMs
• Customizable avatar expressions via agent prompts

Installation

uv add "vision-agents[lemonslice]"
# or directly
uv add vision-agents-plugins-lemonslice

Quick Start

import asyncio
from uuid import uuid4
from dotenv import load_dotenv

from vision_agents.core import User, Agent
from vision_agents.plugins import cartesia, deepgram, getstream, gemini, lemonslice

load_dotenv()


async def start_avatar_agent():
    agent = Agent(
        edge=getstream.Edge(),
        agent_user=User(name="AI Assistant with Avatar", id="agent"),
        instructions="You're a friendly AI assistant.",

        llm=gemini.LLM(),
        tts=cartesia.TTS(),
        stt=deepgram.STT(),

        avatar=lemonslice.Avatar(agent_id="your-avatar-id"),
    )

    call = await agent.create_call("default", str(uuid4()))

    async with agent.join(call):
        await agent.simple_response("Hello! I'm your AI assistant with an avatar.")
        await agent.finish()


if __name__ == "__main__":
    asyncio.run(start_avatar_agent())

Configuration

Environment Variables

LEMONSLICE_API_KEY=your_lemonslice_api_key
LEMONSLICE_AGENT_ID=your_agent_id
# Or, instead of LEMONSLICE_AGENT_ID:
# LEMONSLICE_AGENT_IMAGE_URL=https://example.com/avatar.png

# LemonSlice uses LiveKit as a transport for audio and video
LIVEKIT_URL=wss://your-livekit-server.com
LIVEKIT_API_KEY=your_livekit_api_key
LIVEKIT_API_SECRET=your_livekit_api_secret

Avatar Options

lemonslice.Avatar(
    agent_id="your-avatar-id",  # LemonSlice agent ID (or set LEMONSLICE_AGENT_ID env var)
    agent_image_url=None,  # Custom image URL, 368x560px (or set LEMONSLICE_AGENT_IMAGE_URL env var)
    agent_prompt=None,  # Prompt to influence avatar expressions/movements
    api_key=None,  # Optional: override LEMONSLICE_API_KEY env var
    idle_timeout=None,  # Session timeout in seconds
    livekit_url=None,  # Optional: override LIVEKIT_URL env var
    livekit_api_key=None,  # Optional: override LIVEKIT_API_KEY env var
    livekit_api_secret=None,  # Optional: override LIVEKIT_API_SECRET env var
    width=1920,  # Output video width in pixels
    height=1080,  # Output video height in pixels
)

How It Works

1. LemonSlice Session: Creates a session via LemonSlice API, and joins the LiveKit room as a participant
2. Audio Forwarding: TTS audio is captured and sent to LemonSlice via the room
3. Avatar Generation: LemonSlice generates synchronized avatar video and audio
4. Video Streaming: Avatar video is streamed to call participants via GetStream Edge

Requirements

• Python 3.10+
• LemonSlice API key (get one at lemonslice.com)
• LiveKit server (cloud or self-hosted)
• GetStream account for video calls
• TTS provider (Cartesia, ElevenLabs, etc.) or Realtime LLM

License

MIT

Links

• Documentation
• GitHub
• LemonSlice Docs