fl-studio-mcp

An open-source MCP server that connects Claude (Claude Desktop or Claude Code) to Image-Line FL Studio. Ask Claude in plain language to start playback, set the tempo, gain-stage your mixer, program drum patterns, write chord progressions into the piano roll, or audit your mix for clipping.

Built by sorkthropic. MIT licensed.

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How it works

FL Studio has no external API — only two Python environments inside it:

Environment	Runs	Can touch
MIDI device scripts (device_*.py)	continuously	transport, mixer, channels, patterns, general
Piano roll scripts (.pyscript)	on demand from the piano roll menu	notes, markers, score

So this project bridges the gap with files + a virtual MIDI cable:

Claude ──MCP──▶ fl-studio-mcp server
                   │ 1. writes  ~/.fl-studio-mcp/request.json
                   │ 2. sends MIDI CC 110 through the virtual cable ("doorbell")
                   ▼
        FL Studio device script (device_FLStudioMCP.py)
                   │ 3. reads the request, calls the FL Studio Python API
                   │ 4. writes  ~/.fl-studio-mcp/response.json
                   ▼
        fl-studio-mcp server reads the response ──▶ Claude

Piano roll edits are special: FL Studio only allows note editing from on-demand piano roll scripts. Claude's note tools therefore queue the notes to ~/.fl-studio-mcp/pianoroll_queue.json, and you apply them by running Tools ▸ Scripts ▸ MCP PianoRoll inside the piano roll (one click; undo works normally).

Note: the mailbox lives in ~/.fl-studio-mcp/ rather than /tmp because /tmp doesn't exist on Windows and temp paths can differ per process on macOS — the home folder is the one path both sides always agree on.

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Setup

1. Install this package

git clone https://github.com/alansork/fl-studio-mcp
cd fl-studio-mcp
pip install -e .        # or: uv sync

2. Create the virtual MIDI cable

Windows — loopMIDI

1. Install loopMIDI.
2. Open it and create a port named FL MCP (any name works; this one is auto-detected).
3. Leave loopMIDI running — the port only exists while it runs.

macOS — nothing to do

The server creates its own virtual port named FL MCP automatically the first time it needs one. FL Studio lists it as an input while the server is running. (If you prefer an always-on port that exists even when the server is down, enable the IAC Driver in Audio MIDI Setup — Window ▸ Show MIDI Studio ▸ double-click IAC Driver ▸ tick Device is online — and it will be used instead.)

If auto-detection picks the wrong port, set the environment variable FL_MCP_MIDI_PORT to (part of) the right port's name.

3. Install the FL Studio scripts

python3 install.py

This copies:

• device_FLStudioMCP.py → .../FL Studio/Settings/Hardware/FLStudioMCP/
• MCP_PianoRoll.pyscript → .../FL Studio/Settings/Piano roll scripts/

and offers to register the server in Claude Desktop's config.

4. Wire it up inside FL Studio

1. Restart FL Studio (it scans for scripts at startup).
2. Options ▸ MIDI Settings.
3. In the Input list, select your virtual port (FL MCP / loopMIDI / IAC).
4. Set Controller type to FL Studio MCP Bridge and click Enable.
5. You should see FL Studio MCP Bridge v0.1.0 ready in the script output (View ▸ Script output).

5. Register with Claude

Claude Desktop — install.py can do this for you, or add manually to claude_desktop_config.json:

{
  "mcpServers": {
    "fl-studio-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/fl-studio-mcp", "fl-studio-mcp"]
    }
  }
}

Claude Code:

claude mcp add fl-studio-mcp -- uv run --directory /path/to/fl-studio-mcp fl-studio-mcp

Then ask Claude: "Run fl_check_bridge_status" — it should report the MIDI port and FL Studio answering the ping.

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Tools

Transport (transport_tools.py)

Tool	What it does
fl_play / fl_stop / fl_pause	Playback control
fl_set_tempo(bpm)	Set tempo (10–520 BPM)
fl_set_loop_mode(mode)	"pattern" or "song" mode
fl_toggle_record	Arm/disarm recording
fl_get_transport_state	BPM, play/record state, song position

Mixer (mixer_tools.py)

Tool	What it does
fl_get_mixer_summary	Table of names, volumes, pans, mutes, colors
fl_set_track_volume(track, volume)	Fader (0–1; 0.8 = 0 dB)
fl_set_track_pan(track, pan)	Pan (-1 to 1)
fl_mute_track(track, state)	Mute/unmute
fl_solo_track(track, mode)	Solo with isolation options
fl_set_track_name_color(track, name, hex)	Label + color
fl_route_track(source, target, enable)	Bus/sidechain routing

Channel rack (channel_tools.py)

Tool	What it does
fl_list_channels	Channels + their mixer assignments
fl_set_channel_pitch_pan_vol(...)	Per-channel vol/pan/pitch
fl_set_step_sequencer(channel, "1000100010001000")	Program drum steps
fl_assign_channel_to_mixer(channel, track)	Route channel → insert
fl_mute_channel(channel, state)	Mute/unmute a channel

Piano roll (pianoroll_tools.py) — queued; apply with the MCP PianoRoll script

Tool	What it does
fl_add_chord_progression("C", "major", ["I","V","vi","IV"], ...)	Music theory → notes
fl_add_notes([{pitch, start, length, velocity}, ...])	Arbitrary notes
fl_quantize_piano_roll("1/16")	Snap notes to a grid
fl_clear_piano_roll	Remove all notes (undoable)

Diagnostics (diagnostic_tools.py)

Tool	What it does
fl_diagnose_mix	Clipping / headroom / L-R imbalance report (run during playback)
fl_get_project_info	Tempo, PPQ, channel/pattern/track counts
fl_check_bridge_status	Health-check the whole bridge — run this first when debugging

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Development

Run the test suite (no FL Studio or MIDI hardware needed):

python3 -m unittest discover -s tests

Troubleshooting

Symptom	Fix
"No virtual MIDI cable found"	Start loopMIDI (Win) / enable IAC (macOS); check FL_MCP_MIDI_PORT
"FL Studio did not respond"	FL open? Script enabled in MIDI Settings? Right input port?
Notes don't appear	Piano roll tools only queue — run Tools ▸ Scripts ▸ MCP PianoRoll
fl_diagnose_mix shows all zeros	Peaks are only measured during playback — press play first

License

MIT © sorkthropic