NUX MG-30 MCP server

nux-mg30-mcp

<!-- mcp-name: io.github.voronkovd/nux-mg30-mcp -->

An MCP server that lets an AI assistant (Claude Desktop or any other MCP client) control a NUX MG-30 guitar processor over USB MIDI.

Describe the sound you want in plain words ("tight Children of Bodom rhythm tone", "less fizz, more mids on the lead"), and the assistant picks models, turns knobs, saves and names presets on the unit.

Unofficial project. It is not affiliated with or endorsed by NUX / Cherub Technology. The preset protocol was reverse-engineered on firmware 5.0.2, and other firmware versions may differ. Writing presets overwrites slots on your device, so run backuppresets first**.

What it can do

• Live editing: select a model in any block (35 amps, 24 cabs/IRs, 15 drives, 14 modulations, 8 delays, 6 reverbs, …), switch blocks on and off, set knobs by name (gain, middle, 1.2k, subd, …).
• Read presets: list all 128 presets with names and amps, decode any preset (name, signal chain, models, knob values), and read the edit buffer including unsaved edits.
• Write presets: save the edit buffer to any slot with a name, rename presets, and back up or restore presets to and from JSON files. Every write is verified by reading it back.
• Tone recipes: apply a whole tone from a JSON patch file. Examples are in examples/patches.

Requirements

• A NUX MG-30 connected over USB. The device shows up as a class-compliant MIDI port.
• Python 3.10+.
• An MCP client, for example Claude Desktop.

The server has to run on the computer the MG-30 is plugged into, because it needs direct access to the USB MIDI port. Development and testing were done on macOS; Linux and Windows should work through python-rtmidi, but they are untested.

Installation

The easiest way is uv: uvx downloads and runs the server, no manual setup needed.

Claude Desktop

Open Settings → Developer → Edit Config and add:

{
  "mcpServers": {
    "nux-mg30": {
      "command": "uvx",
      "args": ["nux-mg30-mcp"]
    }
  }
}

Restart Claude Desktop completely. The tools show up under the nux-mg30 server. If Claude cannot find uvx, use its absolute path (which uvx, typically ~/.local/bin/uvx).

Alternatively, install it with pipx install nux-mg30-mcp or pip install nux-mg30-mcp and use "command": "nux-mg30-mcp".

From source

git clone https://github.com/voronkovd/nux-mg30-mcp.git
cd nux-mg30-mcp
python3 -m venv .venv
.venv/bin/pip install -e .

Then use "command": "/absolute/path/to/nux-mg30-mcp/.venv/bin/nux-mg30-mcp" in the client config.

Optional check without any AI client: lower your volume, then run python scripts/midi_check.py. The script mutes the AMP block for 1.5 seconds and restores it.

Configuration

Put these under "env" in the MCP client config.

First steps

1. Ask the assistant to back up all presets (backup_presets).
2. Ask it to list presets to see what is where.
3. Pick a free or unimportant slot and describe a sound. For example: "Switch to 12C and build a Death 'Sound of Perseverance' rhythm tone, then save it as 'Chuck Rhythm'."

Tools

Shortened. The full README is on GitHub.