SynthLab

A browser-based synthesizer that LLMs can play.

What

Web Audio synth controllable via MCP, so Claude can play music programmatically.

Claude: "Play a I-IV-V-I progression"
     │
     ▼ MCP
┌─────────────┐      ┌─────────────┐
│ MCP Server  │──ws──│  Browser    │──► 🔊
└─────────────┘      └─────────────┘

Quick Start

npm install
npm run dev          # Start synth at http://localhost:3000

Open browser, click "Start Audio", then use Claude Code to play:

> Play a C major chord
> Play Für Elise
> Make it sound like a bass and play something funky

MCP Tools

Tool	Description
play_note	Play a single note (e.g., "C4", "F#3")
play_chord_sequence	Play chord progressions
play_sequence	Play melodies
set_config	Change waveform, filter, envelope
get_config	Read current settings
panic	Stop all notes

Stack

• Synth: Web Audio API (oscillator → filter → gain → output)
• Bridge: MCP server (stdio) + WebSocket to browser
• UI: Vanilla TypeScript, Canvas visualization

License

MIT

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Made by Alé... but mostly Claude 🤖🎹 _{(Don't tell him I wrote this too)}