wretcher207/reaper-daemon

Reaper Daemon is a REAPER MCP server and file bridge for driving REAPER from
an AI agent, including mixing your session with Claude or any other agent.
No network socket, no port, no extensions.
The agent drops a JSON command file in a folder. A Lua script inside REAPER
runs it and writes a JSON result back. That's the whole protocol. It works
with Claude Code, Codex, Cursor, or anything else that can read and write
files, and an optional stdio MCP server, reaper_mcp.py, exposes the same
bridge as tools for Claude Desktop and any other MCP client.
macOS, Windows, Linux. Pure Lua inside REAPER, plain Python 3 outside, no
pip packages for the core bridge and MCP server.
Audio-to-drum MIDI transcription uses a separate optional
model environment. Every change runs inside a REAPER undo block, so Ctrl+Z
reverts anything an agent does.
Install
Reaper Daemon has two halves, a Lua bridge that runs inside REAPER and the
tools that talk to it. Both come from a clone of this repository on the
computer REAPER runs on, so install here first, even if you found it through
the Claude plugin directory.
Restart REAPER, then check the bridge is alive:
Rendering and audio capture are off until you allow them, and every
measurement needs them, including verify_change. To do that, run:
Saving the project and changing REAPER preferences have their own switches;
see docs/install.md.
Prefer ReaPack, or want to load the bridge by hand? See docs/install.md.
Claude plugin
The repository is also a Claude plugin. It bundles the MCP server with five
skills: setup, drum programming, drum humanizing, guitar and bass parts, and
MIDI for an existing arrangement. The plugin drives the install above, so if
you added it before installing, ask Claude to set up Reaper Daemon. The setup
skill finds what's missing, runs the clone and installer with you, asks which
disk writes to allow, and checks that REAPER answers.
When you add the plugin, Claude asks for two settings:
- **Reaper Daemon folder**: where you cloned it. Default ~/reaper-daemon.
- **Python command**: default python3. On Windows, use python or py if
python3 isn't on your PATH.
Cowork doesn't ask, so it uses those defaults. To try the plugin in Claude
Code straight from your clone:
The MCP server runs on your computer, next to REAPER. It works in Claude
Code and in Cowork sessions on your machine. Chat on claude.ai loads the
skills but can't reach REAPER.
Mix with an AI agent
Point Claude, or any agent talking to Reaper Daemon, at your open REAPER
session and ask it to work on the mix. It reads every plugin and parameter
with scan_fx, sets FX values in real units like "-2.5 dB", and writes
automation. verify_change captures the track before and after a move and
reports what changed in the audio, so you are not taking its word for it.
Every move sits inside a REAPER undo block, and your ears make the call.
Example prompts:
- "The bass is muddy around 300 Hz, pull it down."
- "Bring the vocal down so it sits with the mix instead of on top."
- "Tune the bass until its LUFS is down 3 dB."
- "What plugins are on the drum bus, and what are they set to?"
See MCP server for setup and Verify for
what the measurements do and do not prove.
What it does
| Area | Commands |
| --- | --- |
| Project | transport, tempo, cursor, time selection, render, save |