Cardinal Server

MCP (Model Context Protocol) server for Cardinal/VCV Rack patch manipulation with AI.

World's first AI integration for modular synthesizer patching!

Features

• Analyze patches - Understand what a patch does
• Create patches - Generate patches from templates
• Add modules - Insert new modules into patches
• Connect modules - Wire up modules with cables
• Suggest modules - Get recommendations based on your goal
• Modify parameters - Adjust knobs and settings

Installation

# Clone this repository
git clone https://github.com/YOUR_USERNAME/cardinal-mcp-server.git
cd cardinal-mcp-server

# Install dependencies
npm install

# Build
npm run build

Usage with Claude Code

Add to your Claude Code settings (~/.claude/settings.json):

{
  "mcpServers": {
    "cardinal": {
      "command": "node",
      "args": ["/path/to/cardinal-mcp-server/dist/index.js"]
    }
  }
}

Then restart Claude Code.

Available Tools

analyze_patch

Analyze a .vcv patch file and explain what it does.

"Analyze the patch at /path/to/my-patch.vcv"

create_patch

Create a new patch from a template.

Templates:

• basic-synth - Simple VCO → ADSR → VCA → Output
• ambient-pad - VCO → VCF (with LFO) → ADSR → VCA → Output
• empty - Blank patch

"Create an ambient pad patch at ~/Desktop/my-ambient.vcv"

suggest_modules

Get module suggestions for what you want to create.

"Suggest modules for a bass sound"
"Suggest modules for an ambient pad"
"Suggest modules for drum sounds"

add_module

Add a module to an existing patch.

"Add a Fundamental:VCF filter to my patch"

connect_modules

Connect two modules with a cable.

"Connect module 2 output 0 to module 3 input 1"

list_modules

List available modules in the database.

"List all oscillator modules"
"List all filter modules"

modify_parameter

Change a parameter value on a module.

"Set the attack (param 0) on module 3 to 0.5"

Example Conversation

You: Create a basic synth patch for me

Claude: I'll create a basic-synth patch with VCO → ADSR → VCA → Audio Out...

You: Make the attack longer

Claude: I'll modify the ADSR attack parameter...

You: Add a filter between the VCO and VCA

Claude: Adding a Fundamental:VCF and reconnecting the signal flow...

Supported Modules

Currently includes definitions for:

• Oscillators: Fundamental VCO, Bogaudio VCO
• Filters: Fundamental VCF
• Envelopes: Fundamental ADSR
• VCAs: Fundamental VCA-1
• Modulation: Fundamental LFO
• Sequencers: Fundamental SEQ-3
• Effects: Valley Plateau
• Utilities: Fundamental Mixer
• I/O: Cardinal HostMIDI, HostAudio2

More modules can be added to the MODULE_DATABASE in the source code.

Contributing

PRs welcome! To add more modules:

1. Add entries to MODULE_DATABASE with description, category, inputs, and outputs
2. Optionally add new patch templates to PATCH_TEMPLATES

License

MIT

Links

• Cardinal - The free and open-source virtual modular synthesizer
• VCV Rack - The original virtual Eurorack
• MCP Protocol - Model Context Protocol specification