phase8-mcp

MCP server for the Korg Phase 8 acoustic synthesizer. Wraps the MIDI implementation documented in the phase 8 owner's manual v1.00 (2025-11-20) so a Model Context Protocol client (Claude Code, Cursor, Continue, etc.) can trigger resonators, drive per-resonator knobs, and modulate globals over USB MIDI.

Written by Ziforge as part of the superclean-collaboration livecoding rig at EMS Stockholm. Companion to the other Ziforge MCPs for Eurorack + hardware synths — see Related MCPs below.

MIDI implementation covered

Direct from section 12.0 (MIDI Implementation Chart) of the phase 8 owner's manual:

Feature	MIDI	Notes
8 resonator triggers	Notes 36-43 (C2..G2)	one note per resonator, left→right
Per-resonator Velocity knob	CC 12-19	resonator 1..8
Per-resonator Envelope knob	CC 20-27	resonator 1..8
Mod Depth	CC 28	0..127
Mod Rate	CC 29	0..127
Air slider	CC 30	0..127
Tempo (Internal)	CC 31	0..127
Shift	CC 90	0..127
Mod Type	CC 92	0 = Pitch Env, 1 = Vibrato
All Sound Off	CC 120	silence all
Reset All Controllers	CC 121	reset all CCs
Program Change	0-7	one of the 8 patches
SysEx	Korg exclusive + Inquiry	via send_raw_sysex

Not implemented (Phase 8 doesn't respond to them):

• Aftertouch (Key's or Channel)
• Pitch Bend

Tools

Category	Tools
Connection	list_midi_ports, connect_phase8(port_pattern, channel), disconnect_phase8, set_channel(channel)
Notes	trigger_resonator(resonator, velocity, duration_ms), release_resonator(resonator), strum(from_res, to_res, velocity, step_ms)
Per-resonator CCs	set_velocity_knob(resonator, value), set_envelope_knob(resonator, value)
Global CCs	set_mod_depth, set_mod_rate, set_air, set_tempo, set_shift, set_mod_type(mod_type='vibrato')
Master	all_sound_off, reset_all_controllers, program_change(program)
Escape hatches	send_raw_sysex(hex_bytes), send_cc(controller, value)

Install

From PyPI (once published) or directly from GitHub:

pip install git+https://github.com/Ziforge/phase8-mcp

Or in a checkout:

git clone https://github.com/Ziforge/phase8-mcp
cd phase8-mcp
pip install -e .

Auto-connects on startup to any MIDI port whose name contains phase8. Override with connect_phase8(port_pattern="...", channel=N).

Wiring it into Claude Code

{
  "mcpServers": {
    "phase8": {
      "command": "phase8-mcp"
    }
  }
}

Example prompts (for the MCP client)

• "Play a slow strum across all 8 resonators, 100 ms per note"
• "Set resonator 5's envelope knob to 80 and its velocity to 60"
• "Change to patch 3, then trigger resonator 1 for 2 seconds"
• "Enable vibrato mod at depth 90, rate 40"

Related MCPs

Ziforge maintains several MCP servers for the hardware in the same livecoding rig — all follow the same shape (FastMCP + python-rtmidi, auto-connect by port-name substring, typed helpers for the top of the MIDI chart plus escape hatches for the rest):

MCP	For
disting-nt-mcp	Expert Sleepers Disting NT
fh2-mcp	Expert Sleepers FH-2 MIDI-to-CV
es9-mcp	Expert Sleepers ES-9 audio interface
erae-mcp	Embodme ERAE Touch II
cirklon-mcp	Sequentix Cirklon sequencer
elektron-mcp	fork of zerubeus/elektron-mcp — Digitone, Digitakt, etc.

Contributing

Pull requests welcome. Suggested workflow:

1. Fork + branch.
2. pip install -e .[dev] (once dev extras land) or just install the base deps and run against a physical Phase 8 or via a virtual MIDI port for smoke testing.
3. If you're adding a Korg SysEx opcode or an undocumented CC that the manual doesn't cover, cite the source (community wiki, forum thread, sniffed capture) so future maintainers can reproduce.
4. Keep the style consistent with the other Ziforge MCPs — one server.py with FastMCP tools, a pyproject.toml, a README with the MIDI table + tools table.

Attribution

MIDI implementation chart transcribed from the phase 8 owner's manual v1.00 (Korg, 2025-11-20), section 12.0. Manual PDF available from Korg's support page for the Phase 8.

License

GPL v2. See LICENSE.