Cubase MCP Server

This repository implements a Cubase MCP server with a real headless control path for Windows using:

• Cubase MIDI Remote API script
• virtual MIDI ports such as loopMIDI
• MIDI request/response SysEx bridge
• MIDI CC command surface triggers
• DirectAccess object and parameter discovery
• MIDI Remote command binding canPerform checks
• selected/focused quick controls for plugin parameters
• filesystem verification for export results
• versioned Windows named-pipe companion bridge protocol
• 238 registered MCP tools with generated static capability audit

It intentionally does not implement or include AutoHotkey, SendKeys, Win32 keyboard/mouse injection, UI Automation clicks, menu automation, dialog automation, screenshot detection, OCR, mouse coordinates, or OS-level shortcut sending.

Real Adapter Mode

The default adapter is composite, not mock.

$env:CUBASE_ADAPTER="composite"
$env:CUBASE_MIDI_INPUT="AI MCP Bridge From Cubase"
$env:CUBASE_MIDI_OUTPUT="AI MCP Bridge To Cubase"
npm run build
node dist/server.js

Use mock only for unit tests or client prototyping:

$env:CUBASE_ADAPTER="mock"
npm run dev

Real Cubase Communication Files

• src/adapters/MidiRemoteAdapter.ts
• src/adapters/MidiCommandSurfaceAdapter.ts
• src/adapters/PluginBridgeAdapter.ts
• src/adapters/ProjectStateAdapter.ts
• src/adapters/CompositeCubaseAdapter.ts
• src/adapters/DirectAccessAdapter.ts
• src/bridge/midi/*
• src/cubase-remote-script/direct-access-bridge.js

Current Evidence Status

The static source tree contains no real capability claims. All entries have testedWithRealCubase: false until npm run cubase:discover or forced real integration tests produce operation-level evidence.

Implemented candidate headless paths include:

• cubase.get_status
• cubase.transport_play
• cubase.transport_stop
• cubase.transport_record
• cubase.transport_rewind
• cubase.transport_forward
• cubase.set_cycle
• cubase.set_metronome
• selected-track cubase.set_track_volume
• selected-track cubase.set_track_pan
• selected-track cubase.set_track_mute
• selected-track cubase.set_track_solo
• selected-track cubase.set_track_record_enable
• selected-track cubase.set_track_monitor
• quick-control based cubase.get_plugin_parameters
• quick-control based cubase.set_plugin_parameter
• user-mapped command trigger cubase.trigger_command
• DirectAccess discovery tools such as cubase.direct_access_discover_object_tree
• command binding registry tools such as cubase.command_binding_get_registry
• current-settings-only cubase.perform_current_audio_export
• DirectAccess semantic mixer/EQ/send/plugin writes using discovered ObjectIDs and parameter tags
• API 1.3 plugin slot assignment and destructive slot reset
• generated Standard MIDI File plus explicit companion import
• asynchronous export/render/scan jobs with bridge progress polling

Unknown or companion-bridge-required until real evidence proves support:

• parameterized project open/save/create
• arbitrary track create/delete/rename/reorder
• MIDI part and note editing
• audio event editing
• render/export/mixdown/stems
• arbitrary plugin insert/preset/window control

Non-executable functions return machine-readable errors such as NEEDS_CUBASE_SIDE_BRIDGE, NEEDS_USER_SETUP, BLOCKED_BY_CUBASE_API, or BLOCKED_BY_NO_HEADLESS_API.

The complete architecture, tool contract, and generated per-tool audit are in docs/architecture.md, docs/tools.md, and docs/full-capability-audit.md.

Setup

Read these in order:

1. docs/setup-windows.md
2. docs/setup-virtual-midi.md
3. docs/setup-cubase-midi-remote.md
4. docs/setup-command-surface.md
5. docs/troubleshooting.md

Verification

npm run typecheck
npm test
npm run test:real
npm run build

Generate the timestamped real Cubase evidence bundle with:

npm run cubase:discover

See docs/real-test-guide.md for the exact Windows/Cubase sequence and docs/real-test-report-schema.md for the evidence contract. npm test is unit/mock evidence only. npm run test:real detects its npm lifecycle name and does not skip integration tests when Cubase is unavailable.

Sources

• Steinberg MIDI Remote API Programmer's Guide: https://steinbergmedia.github.io/midiremote_api_doc/
• Steinberg MIDI Remote API Reference: https://steinbergmedia.github.io/midiremote_api_doc/codedoc_api_reference/
• MCP TypeScript SDK: https://ts.sdk.modelcontextprotocol.io/