TwelveTake REAPER MCP

A TwelveTake Studios project.

A comprehensive Model Context Protocol (MCP) server that enables AI assistants to control REAPER DAW for mixing, mastering, MIDI composition, and full music production workflows.

Built by a working producer with 7+ albums released. These aren't theoretical tools—they're battle-tested in real sessions.

Version: 1.3.2

Why This Server

Workflow Automation, Not Just API Wrappers

Most MCP servers just wrap REAPER's API and call it a day. This one includes production workflow helpers that handle multi-step operations in a single call:

Zero Configuration

• File-based communication works immediately — no network setup, no ports to configure
• Stock REAPER Lua only — the bridge script has no dependencies, nothing extra to install in REAPER
• Copy the script, run it, connect your AI assistant

158 Tools Covering Real Production Needs

• Full FX control — add/remove plugins, get/set any parameter by index, manage presets, bypass
• FX parameter automation — automate any plugin knob (flanger depth, filter cutoff, etc.)
• Complete routing — sends, receives, sidechain routing to specific channel pairs
• Automation — create envelopes, add/edit points, set automation modes
• MIDI — create items, add notes individually or in batches, edit velocities
• Audio items — import, split, duplicate, fade, position, mute
• Markers & regions — create, edit, navigate, render by region

Requirements

• REAPER (any recent version)
• Python 3.8+ (for the MCP server)
• An MCP-compatible AI assistant

Installation

1. Install the Bridge Script in REAPER

The bridge script runs inside REAPER and handles communication with the MCP server.

1. Copy reaper_mcp_bridge.lua to your REAPER Scripts folder:
   • Windows: %APPDATA%\REAPER\Scripts\
   • macOS: ~/Library/Application Support/REAPER/Scripts/
   • Linux: ~/.config/REAPER/Scripts/
2. In REAPER: Actions → Show action list → Load ReaScript
3. Select reaper_mcp_bridge.lua and click Run

You should see "REAPER MCP Bridge started" in REAPER's console.

2. Install the MCP Server

pip install -r requirements.txt

Or install dependencies directly:

pip install mcp httpx

3. Configure Your AI Assistant

Add to your MCP client's configuration (e.g., .mcp.json):

{
  "mcpServers": {
    "reaper": {
      "command": "python",
      "args": ["path/to/reaper_mcp_server.py"]
    }
  }
}

4. Verify Connection

python test_connection.py

Communication Modes

The file-based bridge is the supported path — it is reliable and needs no extra setup. HTTP mode is deprecated (see below).

File-Based (Default, Recommended)

Uses JSON files for communication. More reliable, no network configuration needed. This is the only actively maintained path; all tools are guaranteed to work here.

MCP Server                    REAPER Bridge
    │                              │
    ├── writes request_N.json ────►│
    │                              ├── processes request
    │◄── reads response_N.json ────┤

Bridge directory: %APPDATA%\REAPER\Scripts\mcp_bridge_data

HTTP Mode (Deprecated)

Deprecated as of v1.2.1. The HTTP bridges (reaper_web_server.lua / reaper_web_server.py) are kept for existing users but are no longer maintained and will not receive new tools. They may be removed in a future major release (v2.0). Use the file bridge instead.

Uses HTTP requests on localhost. Requires additional setup:

• Lua HTTP bridge: Requires LuaSocket (install via ReaPack → "sockmonkey")
• Python HTTP bridge: Requires Python enabled in REAPER preferences

# Set environment variable to use HTTP mode
REAPER_COMM_MODE=http python reaper_mcp_server.py

Default port: 9000

Quick Start Examples

Basic Track Operations

"How many tracks are in my project?"
"Create a new track called 'Vocals'"
"Set track 0 volume to -6dB"
"Mute track 2"
"Solo the drums track"

Mixing

"Add ReaComp to the bass track"
"Set up sidechain compression from the kick to the bass"
"Create a drum bus and route tracks 0-3 to it"
"Add a mastering chain to the master track"

FX and Parameters

"What plugins are on track 0?"
"Get the parameters for the compressor on track 1"
"Set the threshold to -20dB"
"Bypass the EQ on the vocal track"

MIDI Composition

"Create a 4-bar MIDI item on track 0"
"Add a C major chord at the start"
"Get all the notes in the MIDI item"
"Set the velocity of note 0 to 100"

Transport and Navigation

"Play the project"
"Stop playback"
"Set the cursor to 30 seconds"
"Add a marker called 'Chorus' at the current position"

Project Management

"What's the project tempo?"
"Set the tempo to 120 BPM"
"Save the project"
"Render to D:/Output/mix.wav"

Tool Reference

Track Operations (23 tools)

FX Operations (16 tools)

Take FX Operations (11 tools)

Per-take (per-item) FX, mirroring the track FX tools. Every take is addressed by (track_index, item_index, take_index).

Take Management & Comping (7 tools)

Multi-take workflows: list/switch/delete takes, explode/crop, REAPER 7 fixed-lane comping.

Routing (9 tools)

Transport (10 tools)

Project (15 tools)

MIDI Operations (8 tools)

Audio Items (17 tools)

Markers & Regions (8 tools)

Automation (8 tools)

FX Parameter Automation (5 tools)

Selection & Editing (11 tools)

Mixing Helpers (6 tools)

Advanced (4 tools)

Track Indexing

• Regular tracks: 0-based index (first track = 0)
• Master track: Use index -1

"Set the master track volume to -3dB"  → track_index = -1
"Mute track 1"                          → track_index = 1 (second track)

Common Plugin Names

Use these names with track_fx_add_by_name():

Third-party plugins use their full name as shown in REAPER's FX browser.

Troubleshooting

"Cannot connect to REAPER"

1. Ensure REAPER is running
2. Ensure the bridge script is running (check REAPER's console)
3. For file mode: verify the bridge directory exists
4. For HTTP mode: check port 9000 isn't blocked

"Track not found"

• Track indices are 0-based
• Use -1 for master track
• Check track count with get_track_count()

Bridge script won't load

• Lua: Ensure LuaSocket is installed (ReaPack → "sockmonkey")
• Python: Enable Python in REAPER preferences

Slow response

• File-based mode has ~50ms latency per call
• Batch operations when possible (e.g., add_midi_notes_batch)

Environment Variables

License

MIT License - see LICENSE

TwelveTake Studios LLC Website: twelvetake.com Contact: contact@twelvetake.com