Chord

The audio engine for everything. Describe sound, get sound.

For Developers

npm install @chord/web

import { Chord } from '@chord/web';

// Create an engine, add nodes, connect them, press play.
const engine = new Chord();
const osc = engine.addNode('oscillator');
const filter = engine.addNode('filter');
const reverb = engine.addNode('reverb');
engine.connect(osc, 'out', filter, 'in');
engine.connect(filter, 'out', reverb, 'in');
engine.setParameter(osc, 'frequency', 261.63);
engine.setParameter(filter, 'cutoff', 2000);
await engine.start();

What Chord Does

Chord is a real-time audio synthesis engine. It runs in any browser via Web Audio API with zero dependencies. No audio files. No samples. Every sound is synthesized from mathematical models — oscillators, filters, effects, sequencers, physical models.

You build a node graph. Chord plays it.

// DSL — write patches as code
import { patch, osc, filter, delay, reverb, output, lfo, euclidean } from '@chord/web';

export default patch('ambient-garden', { tempo: 85, key: 'C', scale: 'minor' }, (p) => {
  const rhythm = euclidean({ steps: 16, pulses: 7 });
  const synth = osc({ waveform: 'saw', detune: 12 });
  const filt = filter({ type: 'lowpass', cutoff: 2000, resonance: 0.3 });
  const space = reverb({ decay: 3.5, mix: 0.25, damping: 0.6 });
  const mod = lfo({ rate: 0.15, depth: 1200 });

  mod.connect(filt, 'cutoff');
  rhythm.connect(synth).connect(filt).connect(space).connect(output());

  p.expose('brightness', filt, 'cutoff', { min: 200, max: 8000 });
});

The Engine

Under the hood, Chord runs a full synthesis engine:

• 47 node types — oscillators, filters, effects, sequencers, physical models, drums, granular, waveshapers
• 6 sequencer types — step, Euclidean, Markov, gravity, cellular automata, polyrhythm
• 18 visualizers — waveform, spectrum, particles, piano roll, spectrogram, terrain, network, and more
• Real-time diagnostics — auto-prevents clipping, clicks, DC offset, NaN
• Professional mixing — master limiter, auto gain staging, bus compression
• DSL — write patches as TypeScript code with full type safety
• MCP integration — every feature programmable by AI assistants via Model Context Protocol

All of this is accessible through a clean API. Built in Rust (desktop/WASM), runs on Web Audio (browser).

Architecture

┌────────────────────────────────────────────────────────────┐
│                    Tauri Desktop App                        │
│  ┌──────────────────────────────┐ ┌─────────────────────┐  │
│  │       React Frontend         │ │   Rust Backend       │  │
│  │  Canvas · Timeline · Piano   │ │  Audio Graph         │  │
│  │  Inspector · Mixer · Browser │ │  DSP Runtime         │  │
│  │                              │ │  Audio I/O           │  │
│  │  Yjs CRDT Document Model     │ │  Plugin Host         │  │
│  └──────────────────────────────┘ │  Node Library        │  │
│                                   │  MIDI Engine         │  │
│  Tauri IPC + Shared Memory       │  Diagnostics          │  │
│                                   └─────────────────────┘  │
└────────────────────────────────────────────────────────────┘
         │                                     │
         │             ┌──────────┐            │
         └─────────────│MCP Server│────────────┘
                       └────┬─────┘
                            │
                   Claude Code / AI

Packages

Package	Description
@chord/web	Browser SDK — nodes, connections, DSL, visualizers
@chord/cli	CLI tool — init, create, validate, build, search, publish
@chord/document-model	Yjs CRDT document schema for collaborative editing
@chord/gesture-system	MediaPipe hand/body/face tracking for gestural control
@chord/controller-integration	Hardware MIDI controller auto-mapping

Rust Crates

Crate	Description
audio-graph	Core graph data structure + topological sort compiler
dsp-runtime	Real-time audio processing engine
audio-io	CPAL-based cross-platform audio I/O
plugin-host	VST3/CLAP/AU plugin hosting
node-library	All 47 built-in node implementations
midi-engine	MIDI I/O and processing
diagnostics	Audio diagnostics, signal monitoring, profiling
export-engine	Compile patches to web, desktop, VST3, CLAP targets
mcp-server	MCP server for AI integration
scripting-runtime	Expression/code node execution
testing-framework	Patch testing & audio assertions
chord-wasm	WebAssembly compilation target

Quick Links

• API Reference
• Sound Description Guide
• Sound Design Guide
• Visualizers
• React Integration
• DSL Reference
• MCP Integration
• Community Library
• Desktop App
• Examples

Build

# Rust
cargo build --workspace
cargo test --workspace

# TypeScript
pnpm install
pnpm build
pnpm test

# Desktop app
cd app && pnpm tauri dev

# MCP server
cargo run -p chord-mcp-server

License

MIT