Logic Pro MCP Server

Bidirectional, stateful control of Logic Pro from AI assistants. Combines 5 native macOS control channels (CoreMIDI, Accessibility, CGEvent, AppleScript, OSC) into a single MCP server with smart routing, fallback chains, and sub-millisecond transport latency.

8 tools, 7 resources, ~3k context tokens. Not 100+ individual tools.

How It Works

Claude ──── 8 dispatcher tools ──── logic_transport("play", {})
         │                           logic_tracks("mute", {track: 3})
         │  7 MCP resources ──────── logic://transport/state
         │  (zero tool cost)         logic://tracks
         ▼
   ┌─── LogicProMCP ──────────────────────────────┐
   │  Command Dispatcher → Channel Router          │
   │     │       │       │       │       │         │
   │  CoreMIDI   AX    CGEvent  AS     OSC        │
   │   <1ms    ~15ms    <2ms   ~200ms  <1ms       │
   └───────────────────────────────────────────────┘

Each command routes through the fastest available channel, with automatic fallback if the primary fails.

Tools & Resources

Tools (8 dispatchers — all actions)

Tool	Commands	Examples
logic_transport	play, stop, record, set_tempo, goto_position...	logic_transport("set_tempo", {tempo: 140})
logic_tracks	select, create_audio, mute, solo, arm, rename...	logic_tracks("mute", {index: 2, enabled: true})
logic_mixer	set_volume, set_pan, insert_plugin, bypass_plugin...	logic_mixer("set_volume", {track: 0, value: 0.8})
logic_midi	send_note, send_cc, send_chord, mmc_play...	logic_midi("send_note", {note: 60, velocity: 100, channel: 1, duration_ms: 500})
logic_edit	undo, redo, cut, copy, paste, quantize, split...	logic_edit("quantize", {value: "1/16"})
logic_navigate	goto_bar, create_marker, toggle_view, set_zoom...	logic_navigate("toggle_view", {view: "mixer"})
logic_project	new, open, save, bounce, launch, quit	logic_project("open", {path: "/path/to/song.logicx"})
logic_system	health, permissions, refresh_cache, help	logic_system("help", {category: "transport"})

Resources (7 URIs — zero context cost)

URI	Description	Refresh
logic://transport/state	Playing/recording/tempo/position/cycle	500ms
logic://tracks	All tracks with mute/solo/arm states	2s
logic://tracks/{index}	Single track detail	2s
logic://mixer	All channel strips: volume, pan, plugins	2s
logic://project/info	Project name, sample rate, time sig	5s
logic://midi/ports	Available MIDI ports	10s
logic://system/health	Channel status, cache, permissions	on-demand

Installation

Quick Install (Script)

curl -fsSL https://raw.githubusercontent.com/koltyj/logic-pro-mcp/main/Scripts/install.sh | bash

Download Binary

Grab the latest universal macOS binary from GitHub Releases, then:

chmod +x LogicProMCP
sudo mv LogicProMCP /usr/local/bin/

Build from Source

Requires Swift 6.0+ and macOS 14+.

git clone https://github.com/koltyj/logic-pro-mcp.git
cd logic-pro-mcp
swift build -c release
# Binary at .build/release/LogicProMCP

Register with Claude Code

claude mcp add --scope user logic-pro -- LogicProMCP

Claude Desktop (Manual Config)

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "logic-pro": {
      "command": "/usr/local/bin/LogicProMCP",
      "args": []
    }
  }
}

Permissions

The server requires two macOS permissions:

1. Accessibility — System Settings > Privacy & Security > Accessibility > add your terminal app
2. Automation — System Settings > Privacy & Security > Automation > allow control of Logic Pro

Check permission status:

LogicProMCP --check-permissions

Usage

Once registered, ask your AI assistant naturally:

• "What tracks do I have?" — reads logic://tracks resource
• "Mute track 3" — logic_tracks("mute", {index: 3, enabled: true})
• "Set tempo to 128" — logic_transport("set_tempo", {tempo: 128})
• "Play a C major chord" — logic_midi("send_chord", {notes: [60,64,67], ...})
• "Show me the mixer" — logic_navigate("toggle_view", {view: "mixer"})

For full command reference: logic_system("help", {category: "all"})

Architecture

Channel Routing

Channel	Latency	Used For
CoreMIDI	<1ms	Transport (MMC), note/CC/sysex sending
Accessibility	~15ms	State reading, UI button clicks, slider values
CGEvent	<2ms	Keyboard shortcuts (postToPid, no focus needed)
AppleScript	~200ms	App lifecycle only (launch, quit, open file)
OSC	<1ms	Mixer control (requires Logic Pro OSC setup)

State Cache

Background Accessibility polling with adaptive intervals:

• Active (tool used <5s ago): 500ms transport, 2s tracks/mixer
• Light (5-30s idle): 2s all
• Idle (>30s): 5s all, near-zero CPU

Context Efficiency

Approach	Tools	Resources	Context Cost
Typical MCP server	100+ tools	0	~40k tokens
This server	8 tools	7 resources	~3k tokens

Same 100+ operations. 90% less context.

Limitations

Logic Pro does not expose a programmatic API. This server works within macOS platform constraints:

• UI element paths may change between Logic Pro versions
• Some deep state (automation curves, region MIDI data) is not exposed via Accessibility
• AX element labels may be localized on non-English macOS
• Plugin parameter control is limited to what's visible in the UI
• OSC channel requires manual Logic Pro Control Surface setup

This is the ceiling for Logic Pro automation given Apple's constraints.

Development

# Build debug
swift build

# Build release
swift build -c release

# Run tests
swift test

# Check permissions without starting server
.build/debug/LogicProMCP --check-permissions

Project Structure

Sources/LogicProMCP/
  main.swift                 # Entry point
  Server/                    # MCP server + config
  Dispatchers/               # 8 MCP tool dispatchers
  Resources/                 # 7 MCP resource handlers
  Channels/                  # 5 communication channels
  Accessibility/             # AX API wrappers
  MIDI/                      # CoreMIDI engine + MMC
  OSC/                       # UDP client/server
  State/                     # Cache + adaptive poller
  Utilities/                 # Logging, permissions, process utils

License

MIT