# LemonSlice

> 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. Use the LemonSlice API to embed lip-synced avatar video in your product or website over WebRTC.
> Try it out at [lemonslice.com](https://lemonslice.com). Get your API key from the [LemonSlice web app](https://lemonslice.com/sign-in) to start building.

Character World Models go beyond traditional real-time avatars based on deepfake or older generative tech. Create any character from a single image (no training or fine-tuning) and go from image to live video call instantly.

Highlights:
- Ultra-low latency ([benchmarks](https://lemonslice.com/blog/lemonslice-flash)), 1000+ concurrency, multi-hour calls
- Instant avatar creation from 1 photo; 5-minute API setup
- Model capabilities: hand gestures, emotions, holding objects, clothing swaps, physics/spatial modeling, full-body movement, photorealism, and non-human/cartoon characters
- In-call control: update appearance, emotions, and actions during a live session

How a call works: STT/VAD listens → LLM decides the reply → TTS produces audio → LemonSlice turns that audio into real-time character video in a live WebRTC call. LemonSlice is the graphics / “face” layer on top of any TTS and LLM; latency depends heavily on your upstream STT/LLM/TTS.

API inputs: (1) image for appearance, (2) streaming TTS audio for speech, (3) optional Action Engine for gestures/actions (Enterprise).

Primary path: self-managed via LiveKit, Daily/Pipecat, or Agora — you keep STT/LLM/TTS and call UI; LemonSlice adds avatar video. Also available: no-code [Widget](https://lemonslice.com/docs/widget/overview.md) and low-code [Hosted Pipeline](https://lemonslice.com/docs/hosted/overview.md) (LemonSlice manages speech/intelligence).

## Reference

- [Overview](https://lemonslice.com/docs/introduction/index.md): Product + Character World Model overview, capabilities, how it works, and integration options
- [Quickstart (5 min)](https://lemonslice.com/docs/introduction/quickstart.md): Clone a production-ready Next.js + LiveKit agent locally — the recommended starting point
- [Production checklist](https://lemonslice.com/docs/reference/production-checklist.md): Call lifecycle, latency, interruption handling, and production deployment tips
- [LiveKit Integration](https://lemonslice.com/docs/livekit/index.md): Add LemonSlice avatars to a LiveKit Agents pipeline
- [Pipecat Integration](https://lemonslice.com/docs/pipecat/index.md): Add LemonSlice avatars to a Pipecat agent
- [Agora Integration](https://lemonslice.com/docs/agora/index.md): Add LemonSlice avatars to Agora Conversational AI Engine
- [Avatar Image Tips](https://lemonslice.com/docs/prompting-guide/avatar-image-tips.md): Reference image guidance for avatar quality
- [Authentication](https://lemonslice.com/docs/reference/authentication.md): API key setup for self-managed sessions
- [Create session](https://lemonslice.com/docs/api-reference/create-session.md): Start a LiveKit or Pipecat session that takes avatar audio and returns synced video/audio (called by SDK, not directly)
- [Control session](https://lemonslice.com/docs/api-reference/control-session.md): Send control events (emotions, actions) to an active session
- [Create Agora session](https://lemonslice.com/docs/api-reference/create-agora-session.md): Agora Conversational AI Engine session start (called by Agora, not your app)
- [Stop Agora session](https://lemonslice.com/docs/api-reference/stop-agora-session.md): Agora Conversational AI Engine session stop (called by Agora, not your app)
- [Get session](https://lemonslice.com/docs/api-reference/get-session.md): Retrieve status of a session
- [List sessions](https://lemonslice.com/docs/api-reference/list-sessions.md): List session history for your account, including credits used
- [How to Use LemonSlice Actions](https://lemonslice.com/docs/reference/actions.md): Trigger gestures and expressions via the API
- [Green Screen (Chroma Key) Compositing](https://lemonslice.com/docs/reference/green-screen.md): Client-side chroma key for landscape layouts, floating avatars, and custom backgrounds
- [Real-time Updates](https://lemonslice.com/docs/reference/realtime-updates.md): Change the avatar base image mid-call via update-image (<1s)
- [Zoom & meeting platforms](https://lemonslice.com/docs/reference/zoom-meetings.md): Send a LemonSlice avatar into Zoom, Google Meet, Teams, or Webex via LiveKit Agents
- [LemonSlice Lite](https://lemonslice.com/docs/reference/lite-model.md): Lower-cost model ideal for high-volume consumer use cases
- [LemonSlice Flash](https://lemonslice.com/docs/reference/flash-model.md): Fastest model for latency-sensitive applications (~200ms+ faster time-to-first-byte)
- [OpenAPI spec](https://lemonslice.com/docs/openapi.json)

## Examples

- [Examples overview](https://lemonslice.com/docs/examples/index.md)
- [LiveKit app (Python)](https://lemonslice.com/docs/examples/livekit-app-python.md)
- [Multiple Avatars + Chrome Extension](https://lemonslice.com/docs/examples/multiple-avatars-chrome-extension.md)
- [Avatars + Tool Calling](https://lemonslice.com/docs/examples/avatars-tool-calling.md)
- [LiveKit app (Node.js)](https://lemonslice.com/docs/examples/livekit-app-nodejs.md)
- [LiveKit playground demo](https://lemonslice.com/docs/examples/livekit-playground-demo.md)
- [Hosted Daily app](https://lemonslice.com/docs/examples/hosted-daily-app.md)
- [Pipecat app](https://lemonslice.com/docs/examples/pipecat-app.md)
- [LemonSlice + Video Meeting Platforms](https://lemonslice.com/docs/examples/livekit-zoom.md)
- [Green Screen (chroma key) + Landscape demo](https://lemonslice.com/docs/examples/greenscreen-landscape-demo.md)
- [Realtime Image Change demo](https://lemonslice.com/docs/examples/realtime-image-change.md)

## Widget & Hosted

- [Widget Overview](https://lemonslice.com/docs/widget/overview.md): No-backend embeddable web component; paste one line of HTML (good for demos and evaluation)
- [Widget Customization](https://lemonslice.com/docs/widget/customization.md)
- [Widget Controls](https://lemonslice.com/docs/widget/control.md)
- [Widget call metadata](https://lemonslice.com/docs/widget/call-metadata.md)
- [Prompt Engineering Tips](https://lemonslice.com/docs/widget/prompt-engineering.md)
- [Widget embed: Squarespace](https://lemonslice.com/docs/widget/embed-guides/squarespace.md)
- [Widget embed: Shopify](https://lemonslice.com/docs/widget/embed-guides/shopify.md)
- [Widget embed: Wix](https://lemonslice.com/docs/widget/embed-guides/wix.md)
- [Widget embed: Next.js](https://lemonslice.com/docs/widget/embed-guides/nextjs.md)
- [Hosted Pipeline Overview](https://lemonslice.com/docs/hosted/overview.md): LemonSlice manages STT/LLM/TTS; you bring the frontend via Daily rooms
- [Hosted Capabilities](https://lemonslice.com/docs/hosted/capabilities.md)
- [Hosted Daily Integration](https://lemonslice.com/docs/hosted/integrations/daily-room-integration.md)
- [Hosted Authentication](https://lemonslice.com/docs/hosted/endpoint/authentication.md)
- [Create hosted room](https://lemonslice.com/docs/api-reference/create-hosted-session.md): Create a Daily room with a LemonSlice-managed agent
- [Get hosted room](https://lemonslice.com/docs/api-reference/get-hosted-session.md)
- [List hosted rooms](https://lemonslice.com/docs/api-reference/list-hosted-sessions.md)