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Build interactive avatars that can listen, talk and respond directly inside your product or website using the LemonSlice API. ✓ Ultra-low latency
✓ 1000+ concurrency 
✓ Multi-hour long calls
✓ Instant avatar creation (1 photo) 
✓ 5-minute API setup 

Quickstart (5 min)

Build a production-ready avatar app with Next.js + LiveKit in 5 minutes

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The most advanced interactive avatar model

LemonSlice is an AI research lab that built the world’s first Character World Model: interactive characters that talk, listen, and react in real-time based on your conversations. Character World Models are more advanced than traditional real-time avatars, which are based on deepfake or older generative technology. Here are some of the capabilities of the LemonSlice model:
Create any character from a single image. No training or fine-tuning required. Go from image to live video call with that character instantly. 

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How it works

Every real-time conversation with a character goes through the following steps: 
  1. A speech-to-text (STT) and voice-activity detection (VAD) model listen to the user
  2. An LLM decides what to say back
  3. Text-to-speech (TTS) turns the reply into audio 
  4. LemonSlice turns the audio into a real-time video of the character speaking within a live video call
All of this runs within a harness that manages the orchestration and WebRTC connection. LemonSlice connects to all major WebRTC providers to make orchestration easy. Integration diagram The inputs to the LemonSlice API are: 
  1. Image - defines the appearance of your character.
  2. Audio - streaming audio from a TTS model like ElevenLabs or Cartesia. This audio is exactly what your character will say.
  3. (optional) Action Engine - determines what actions (waving, holding a phone, looking away) the character should take during the conversation. Currently Enterprise only.
The quality of your avatar is heavily determined by your image. See Avatar Image Tips for framing and posing tips.

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Integrate real-time avatars into your app

Add LemonSlice to the stack you already use. LemonSlice integrate with all major WebRTC providers like LiveKit, Daily/Pipecat, and Agora. These providers all have Conversational AI toolkits that make it simple to combine any LLM, TTS, and STT component with LemonSlice.
  1. Pick a framework — follow the LiveKit integration or Pipecat integration guide.
  2. Build your UI — run your own call lifecycle and frontend around the avatar session. See Production checklist for call lifecycle patterns.
You can think of LemonSlice like a graphics layer or “face layer” that’s added on top of your voice agent. It is compatible with any TTS and LLM model.
Or, use one of the low-code options below to get started with minimal engineering effort. 
The Widget is a no-code solution for adding an avatar to your website. It’s like embedding a YouTube video - just 2 lines of code. LemonSlice takes care of everything else.The Hosted Pipeline is a low-code solution. LemonSlice manages the entire avatar and agent infrastructure. You build the UI for the avatar call.Here’s a comparison of the options:
Self-managed pipelineHosted pipelineWidget
Complexity⚙️⚙️⚙️ Full code⚙️⚙️ Low code⚙️ No code
You controlSpeech, Intelligence, Call UICall UINothing
LemonSlice controlsAvatarSpeech, Intelligence, AvatarSpeech, Intelligence, Avatar, Call UI

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Try the live demo