Supercollider

MCP bridge to a running SuperCollider IDE. Lets an MCP client (Claude Code, Cursor, Continue, etc.) evaluate SC code, query values, capture the post window, and screenshot Qt windows without the user having to paste anything.

Sits alongside the other Ziforge MCPs for the EMS Stockholm rig — see Related MCPs.

How it works

sclang has a built-in OSC listener on port 57120. The setup.scd this repo ships with installs an OSCdef on /mcpEval that runs whatever code the MCP sends. Results come back on /mcpReply on port 57121, keyed by a request id.

Once you evaluate setup.scd in your IDE once per SC session, every MCP-side sc_eval call goes through OSC — no need to keep pasting.

Claude ↔ MCP server ↔ OSC :57120 → sclang → OSC :57121 → MCP → Claude

Install

git clone https://github.com/Ziforge/supercollider-mcp
cd supercollider-mcp
pip install -e .

Or with uv:

uv pip install -e .

Wire into Claude Code

{
  "mcpServers": {
    "supercollider": {
      "command": "supercollider-mcp"
    }
  }
}

Setup — one line per SC session

Open your SC IDE, evaluate this once:

"~/Projects/supercollider-mcp/setup.scd".standardizePath.load;

You should see in the post window:

supercollider-mcp: listener installed on /mcpEval + /mcpPost (port 57120).
supercollider-mcp: replies sent to /mcpReply on 57121.

That's it. Now MCP calls work.

Tools

Category	Tool	What it does
Eval	sc_eval(code, timeout)	Send SC code, get result string
Eval	sc_query(expression, timeout)	Same as sc_eval but semantic — for reading state
Eval	sc_post_recent(n)	Last N eval results + errors from the OSC buffer
Patterns	sc_hush()	Pdef.all.do(_.stop)
Server	sc_boot_server()	Boot Server.default
Server	sc_quit_server()	Quit Server.default
Interp	sc_recompile()	Recompile class library (destroys the OSC listener — re-run setup.scd after)
Windows	sc_list_windows()	Enumerate sclang / SuperCollider windows via osascript (macOS)
Windows	sc_screenshot(save_path)	screencapture full screen (macOS) — the sclang Qt windows appear on it
Setup	sc_setup_listener_scd_path()	Return absolute path to setup.scd for the current install

Limitations

• sc_recompile kills the listener. After a class-library recompile, the OSC listener is gone. You must re-evaluate setup.scd. There's no way around this — recompile reboots the interpreter.
• Post window is partial. sc_post_recent only shows results of MCP-issued evaluations, not arbitrary .postln output from patterns or synths. sclang doesn't expose its Post class's output stream over OSC. If you want to capture that too, wire your Pdefs to emit via NetAddr("127.0.0.1", 57121).sendMsg("/mcpReply", 0, 1, "...") explicitly.
• Screenshots are full-screen. Window-ID targeting on macOS needs assistive access permission most sessions don't have. If your terminal has been granted assistive access via System Settings → Privacy → Accessibility, you can tighten this later.

Example prompts (for the MCP client)

• "Evaluate SinOsc.ar(440).play in SC and hush after 2 seconds"
• "What's the current value of ~ws.destName in SC?"
• "Screenshot the SC IDE and describe what the bus view is showing"
• "Recompile the class library, then re-install the mcp listener"

Related MCPs

Repo	For
superclean-mcp	SuperClean pattern control (Pdef.play, hush, list) — layered on top of this
phase8-mcp	Korg Phase 8
disting-nt-mcp	Expert Sleepers Disting NT
fh2-mcp	Expert Sleepers FH-2
es9-mcp	Expert Sleepers ES-9
erae-mcp	Embodme ERAE Touch II
elektron-mcp	Elektron devices (fork of zerubeus)

License

GPL v2. See LICENSE.