Smelter examples

A collection of self-contained example apps built with the Smelter TypeScript SDK. Smelter is a toolkit for real-time, low-latency, programmable video and audio composition, where scenes are described with React components.

Each example lives in its own directory and is independent — pick one, install its dependencies, and run it. Examples are grouped by the Smelter runtime package they use:

• @swmansion/smelter-node — run Smelter from a Node.js process.
• @swmansion/smelter-web-client — drive a remote Smelter server from the browser.
• @swmansion/smelter-web-wasm — run Smelter entirely in the browser via WebAssembly.

Prerequisites

• Node.js 24+ and pnpm.
• ffmpeg and ffplay on your PATH — only needed by the Node.js examples that preview their output locally.

Running an example

Every example follows the same flow:

cd <example-directory>
pnpm install
pnpm start   # or `pnpm dev` for the browser examples

The exact command per example is listed below.

@swmansion/smelter-node

Drive a locally-spawned Smelter binary from a Node.js process — the package downloads and manages the binary for you. Inputs and outputs are configured server-side.

Example	Command	What it shows
node-minimal	pnpm start	Real-time processing: compose a scene, stream it over RTMP, and preview the output with ffplay.
node-offline	pnpm start [files…]	Offline processing: stitch one or more MP4 files into a single output.mp4.
node-yolo-whisper	see its README	A full app: React frontend, Node.js backend, and a Python sidecar running YOLO object detection and Whisper transcription over Smelter's side channel.

@swmansion/smelter-web-client

Control a separate, already-running Smelter server from the browser. React code runs in the browser and sends scene-update requests to the server.

Example	Command	What it shows
web-client-vite	pnpm dev	A Vite + React UI that connects to a Smelter server and updates the composition live.

Requires a running Smelter server. See the Smelter documentation for how to start one.

@swmansion/smelter-web-wasm

Run Smelter inside the browser via WebAssembly. These examples are fully self-contained and need no server or extra infrastructure (Chromium-based browsers only).

Example	Command	What it shows
web-wasm-vite	pnpm dev	A Vite + React app that renders a composition to a <canvas>.
web-wasm-react-router	pnpm dev	A React Router app with two pages: canvas rendering, and WebRTC (WHIP) output with a <video> preview. Both let you add camera and screen share to the scene.
web-wasm-nextjs	pnpm dev	A Next.js app (pinned to 14.2.24 for compatibility with the React version Smelter uses).

Learn more

• Documentation
• Guides
• Smelter on GitHub
• Discord

Smelter is created by Software Mansion

Since 2012, Software Mansion is a software agency with experience in building web and mobile apps as well as complex multimedia solutions. We are Core React Native Contributors and experts in live streaming and broadcasting technologies. We can help you build your next dream product – Hire us.