strudel-claude

An experiment to play and learn Strudel with OpenCode.

A minimal, full-screen live coding environment for making music. Built for AI - exposes REST APIs so agents can compose and control music programmatically.

What is Strudel?

Strudel is a JavaScript port of Tidal Cycles for algorithmic music composition. Write code, make music, in real-time.

// Drums
$: s("bd*4, [~ cp]*2, hh*8").bank("RolandTR909")

// Bass
$: note("<c2 eb2 f2 g2>").s("sawtooth").lpf(400)

Prerequisites

• OpenCode installed
• Node.js 18+ for the server

Quick Start

1. Start the server

npm install
npm run dev

2. Open OpenCode in the project folder

opencode

2. Open an AI agent in the project folder

With OpenCode:

opencode

With Claude Code:

claude

3. Ask for any skill

"Teach me Strudel"          → /tutorial
"Play me a techno set"      → /dj-set
"Compose a synthwave track" → /compose
"Let's make music together" → /interactive

See Skills for AI Agents for more examples.

Keyboard Shortcuts

Shortcut	Action
Cmd+Enter	Play / evaluate code
Cmd+.	Stop

Recording Audio

Capture your Strudel output to WAV:

1. Start playback - Hit play or Cmd+Enter
2. Click the red record button - It pulses and shows duration
3. Click again to stop - A preview toast appears
4. Listen, then Download or Discard

Recording is independent from playback - stop recording anytime without stopping the music.

API for Agents

The REST API allows AI agents to read and write Strudel code, enabling autonomous music composition. Real-time sync via Server-Sent Events means the browser updates instantly when you push code or trigger playback.

Endpoint	Method	Description
/api/code	GET	Get current code and playing state
/api/code	POST	Push new code { "code": "..." }
/api/play	POST	Start playback
/api/stop	POST	Stop playback
/api/status	GET	Get current state
/api/events	GET	SSE stream for real-time updates

Example: AI Composing Music

# Push new code and play
curl -X POST http://localhost:3000/api/code \
  -H "Content-Type: application/json" \
  -d '{"code": "$: s(\"bd*4, cp*2\").bank(\"RolandTR909\")"}'

curl -X POST http://localhost:3000/api/play

Project Structure

src/
├── app/
│   ├── api/                # REST API for agents
│   │   ├── code/           # GET/POST code
│   │   ├── events/         # SSE stream
│   │   ├── play/           # POST play
│   │   ├── stop/           # POST stop
│   │   ├── status/         # GET status
│   │   └── state.ts        # Shared state + event emitter
│   ├── layout.tsx          # Root layout
│   ├── page.tsx            # Home page
│   └── globals.css         # Styles + CodeMirror theme
├── components/
│   └── strudel-editor.tsx  # Main editor
├── hooks/
│   ├── use-strudel.ts      # Strudel lifecycle + SSE sync
│   └── use-audio-recorder.ts # Audio recording to WAV
└── lib/
    ├── constants.ts        # Shared constants
    ├── utils.ts            # Utilities
    └── wav-encoder.ts      # Pure JS WAV encoder

Tech Stack

• Next.js
• Tailwind CSS
• Strudel REPL

Voice Feedback (macOS only)

The AI agent uses the say command for voice feedback. This only works on macOS.

By default, macOS uses basic voices like Daniel or Samantha, but you can enable much better Siri voices that sound way more natural:

Enable Siri Voices

1. Open System Settings → Accessibility → Spoken Content (or press Cmd+Space and search "Spoken Content")
2. Click the ⓘ (info icon) next to System Voice
3. In the voice dropdown, search for "Siri"
4. Download a Siri voice you like
5. Set it as your System Voice - this way all say commands use it automatically

Test it in Terminal:

say "Let's make some music"

Skills for AI Agents

This REPL includes skills that teach AI agents how to make music. The /strudel and /api skills are loaded automatically - the agent already knows the syntax and how to control the app.

Try these:

/tutorial - Learn Strudel & Music Theory

"Teach me Strudel from the beginning"
"Explain how filters work"
"Show me how to make chord progressions"
"Teach me music theory basics"
"What's the difference between major and minor scales?"

/dj-set - Live DJ Sets

"Play me a 5-minute live techno set"
"Create a deep house journey"
"Do a chill ambient set with voice narration"
"Play an indefinite acid house set until I stop you"

/compose - Full Track Compositions

"Compose a 3-minute synthwave track"
"Create a full UK garage song"
"Make a lo-fi hip hop beat"

/interactive - Guided Music Creation

"Let's make music together"
"Help me create a beat"
"Guide me through making a song"

Other Skills

• /visuals - Add visualizations (pianoroll, spiral, oscilloscope)
• /strudel - Syntax reference (loaded automatically)
• /api - REPL control (loaded automatically)

Learn More

• Strudel Docs
• Strudel GitHub
• Tidal Cycles

License

MIT - Free to use, copy, modify, and distribute.

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Made in Blueberry 🫐