FM8 MCP Server

AI-controlled Native Instruments FM8 synthesizer via MIDI and Model Context Protocol.

What This Does

Lets Claude Desktop (or other MCP clients) control your FM8 synthesizer by sending MIDI CC messages through a virtual MIDI port.

Requirements

• Node.js 18+
• Native Instruments FM8
• Virtual MIDI port software:
  • Windows: loopMIDI
  • macOS: IAC Driver (built-in)

Quick Start

git clone https://github.com/thesigma1receptor/fm8MCP.git cd fm8MCP npm install npm run build

Setup Virtual MIDI

Windows

1. Install and run loopMIDI https://www.tobias-erichsen.de/software/loopmidi.html
2. Remove any existing ports
3. Create port named fm8

macOS

1. Open Audio MIDI Setup
2. Window → Show MIDI Studio
3. Double-click IAC Driver
4. Enable "Device is online"
5. Create port named fm8

Configure FM8

1. Set MIDI input to fm8 port by clicking off/on, change to on
2. Go to Master tab and load included MCP.f8c file
3. Right click any operators that are off to enable them

Claude Desktop Setup

Edit your Claude config file:

Windows: %APPDATA%\Claude\claude_desktop_config.json
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Included in repo, or amend yours with:

{ "mcpServers": { "fm8": { "command": "node", "args": [ "C:/path/to/fm8-mcp-server/dist/server.js", "--transport=stdio", "--midi-port-name=fm8", "--channel=1" ] } } }

Restart Claude Desktop and you're ready!

AnythingLLM Setup

Requirements: Ollama with llama3.1 or qwen2.5:4b minimum

Edit: %APPDATA%\anythingllm-desktop\storage\plugins\anythingllm_mcp_servers.json

Included in repo, or amend yours with:

{ "fm8": { "name": "FM8 Control", "command": "node C:/path/to/fm8-mcp-server/dist/server.js", "args": ["--transport=stdio", "--midi-port-name=fm8", "--channel=1"], "env": {}, "cwd": "C:/path/to/fm8-mcp-server" } }

1. Restart AnythingLLM
2. Enable MCP server in workspace settings
3. Use @agent in chat to access tools

What You Can Control

FM8 Matrix (CC 0-62)

All operator-to-operator modulation routes (A→B, B→C, etc.)

Operator Outputs (CC 63-70)

Operator-to-Output levels (A→Out, B→Out, etc.)

Frequency Ratios (CC 72-77)

Harmonic/inharmonic relationships for each operator

See mappings.json for complete CC reference.

Example Claude Prompts

• "Create an FM bell sound"
• "Set operator A to modulate B at 75%"
• "Make a pure sine wave"
• "Route operator C to output at full volume"
• "Show all available FM8 controls"

If you want to give Claude free reign to try things:

-"Ratios are from 0 - 64:1, 127 being 64, feel free to look up fm synthesis techniques. There 8 operators, A-F are pure sine waves, X is a noise oscillator and Z is a filter. Let's see what you can come up with!"

Make it your own!

If you want to add any functionality, ie, more midi cc, use the standalone fm8, turn on midi learn and I used touchosc to make ~80 controls and map things. Look at mappings.json and add start with cc #78.

There are also ways with mcp to give claude memory and better instructions. So he could potentially learn how to make complex sounds.

Tip

This also works from VSCode with copilot.

Start server: node C:\fm8MCP\dist\server.js --transport=stdio --midi-port-name=fm8 --channel=1

Example command for agent:

node -e "const easymidi = require('easymidi'); const out = new easymidi.Output('fm8'); console.log('⚡ Creating neuro bass...'); out.send('cc', {controller: 0, value: 95, channel: 0}); setTimeout(() => out.send('cc', {controller: 1, value: 110, channel: 0}), 20); setTimeout(() => out.send('cc', {controller: 8, value: 105, channel: 0}), 40); setTimeout(() => out.send('cc', {controller: 9, value: 90, channel: 0}), 60); setTimeout(() => out.send('cc', {controller: 17, value: 100, channel: 0}), 80); setTimeout(() => out.send('cc', {controller: 63, value: 127, channel: 0}), 100); setTimeout(() => out.send('cc', {controller: 64, value: 110, channel: 0}), 120); setTimeout(() => { console.log('🎵 Neuro bass loaded! Play low notes (C1-C2)'); process.exit(0); }, 400);"

Troubleshooting

No MIDI signal

• loopMIDI/IAC running?
• FM8 input set to fm8 port?
• MIDI channel matches (default: 1)?

Server won't start

• Run npm run build first
• Check Node version: node --version

Claude can't find it

• Use absolute paths in config
• Forward slashes even on Windows
• Restart Claude after config changes

License

MIT