FL Studio 2025 AI Bridge (fLMCP-2025)

A Model Context Protocol (MCP) bridge that lets an AI assistant (Claude, or any MCP client) read and control FL Studio — extended to actually work on FL Studio 2025 (build 25.2.5), whose locked-down control-script sandbox breaks every socket-based FL bridge.

Attribution

This project is a derivative of geezoria/FLStudioMCP (MIT), which provides the 159-tool MCP server and the FL-side device script. All original credit goes to that project — see LICENSE. This repo adds the FL Studio 2025 compatibility layer and a few new capabilities (below).

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Why this fork exists

On FL Studio 2025 build 25.2.5, control-surface scripts run in a CPython sub-interpreter that blocks threads, sockets, and most os filesystem calls, and never calls OnIdle — so the upstream TCP bridge cannot even open its port. Full diagnosis (with every error, reproduced): docs/FL2025_SANDBOX.md.

This fork makes the bridge work anyway, using only the primitives FL 2025 does allow:

Addition	What it does
file-RPC transport	Request/response over two fixed JSON files (read/write only — no sockets, threads, mkdir, rename, unlink, or glob). Enable with FLMCP_TRANSPORT=file.
MIDI-wake	OnIdle is dead on this build, so the server sends a tiny MIDI note to the loopback port; FL's OnMidiIn (driven by the MIDI engine) fires and pumps the request.
meta.exec escape hatch	Runs arbitrary Python in the live controller interpreter, exposing all ~250 FL API functions (not just the ~159 wrapped handlers). Powers the helpers below and the API mapping in the docs.
pianoroll_apply (exact note editing)	FL sandboxes pyscript file I/O, so the notes are baked into the piano-roll script's source, deployed, and run via the "run last script" hotkey. Sample-accurate composition — no recording jitter.
globalTransport clip placement	FL exposes no placePattern, and ui.paste doesn't touch clips — but transport.globalTransport(FPT_Copy/FPT_Paste) does drive the playlist clipboard. Bridge-only clip placement, playhead-accurate in time.
Note recording	channels.triggerNote while recording writes pitched notes into the piano roll/timeline. Good for sparse phrases and song-mode arrangement.
"Ears" (example)	Play a pattern → capture FL's live output via WASAPI loopback → analyse tempo/key/loudness/brightness with librosa. See examples/.

The high-level helpers live in src/fl_studio_mcp/producer.py: fl_exec, pianoroll_apply, record_performance, arrange_via_recording, copy_clip_range / paste_clips_at / duplicate_clip_range.

Verified end-to-end on FL Studio 2025 build 25.2.5: reads, transport/mixer control, step-sequencer beats, tempo, exact piano-roll note editing, note recording, playlist clip placement, and audio analysis — i.e. the full compose → arrange → listen loop, plus a complete phonk beat built and arranged purely through the bridge.

Quick start (Windows, FL Studio 2025)

git clone https://github.com/Boyan253/fl-studio-2025-ai-bridge.git
cd fl-studio-2025-ai-bridge
./scripts/install_windows.ps1

Then in FL Studio:

1. Install loopMIDI and create a port (e.g. loopMIDI Port).
2. Options > MIDI settings > Input: select the loopMIDI port and set Controller type = fLMCP Bridge (it appears in the "Scripts" section near the top — not alphabetically).
3. Set FLMCP_TRANSPORT=file in your MCP client's env for this server (and FLMCP_MIDI_PORT if your port name differs from loopMIDI).

Smoke test:

$env:FLMCP_TRANSPORT="file"
.\.venv\Scripts\python.exe scripts\smoke_test.py

What works vs. doesn't on FL 2025 25.2.5

• ✅ Reads, transport/mixer control, step-sequencer beats, tempo, note recording, audio analysis
• ✅ Exact piano-roll note editing — via the baked-pyscript route (pianoroll_apply)
• ✅ Playlist clip placement — via transport.globalTransport(FPT_Copy/FPT_Paste) (playhead-accurate; track follows FL's paste anchor)
• ✅ meta.exec — call any of FL's ~250 scripting functions remotely
• ⚠️ Pyscript file I/O stays sealed by FL (worked around by baking notes into the script source)

See docs/FL2025_SANDBOX.md for the complete story, the full enumerated API (proof), and the exact recipes.

License

MIT — see LICENSE. Original work © the FLStudioMCP authors (geezoria/FLStudioMCP); FL-2025 additions contributed on top.