Agent MIDI - Virtual Agentic Keyboard

Agent MIDI is a native Swift programmable MIDI deck for macOS. It runs as an independent virtual MIDI keyboard and can also be embedded inside a SwiftUI IDE. Join the Discord for any issues or troubleshooting https://discord.gg/w6htGsCkx6

Inspired by @xikhar | http://x.com/xikhar

Interoperable with Codex, Claude Code, BuilderStudio, and many other IDEs.

Easy to run, just download and run via

swift run AgentMIDIApp

Current implementation

• Native SwiftUI interface inspired by compact programmable hardware decks
• CoreMIDI virtual source named Agent MIDI
• Note, control-change, and program-change mappings
• Built-in visual programming inspector for every control
• JSON layouts and skins loaded from Application Support
• Host IDE commands for BuilderStudio
• Codex CLI and Claude Code command adapters
• Workspace launch adapters for Visual Studio Code, Cursor, Zed, and Xcode
• Distributed notification event bridge for other native macOS applications
• Reusable AgentMIDIKit Swift package

Run independently

cd AgentMIDI
swift run AgentMIDIApp

The virtual Agent MIDI source appears in CoreMIDI-aware applications while Agent MIDI is running.

Install as a macOS application

cd AgentMIDI
./scripts/install.sh
open "$HOME/Applications/Agent MIDI.app"

Set AGENT_MIDI_INSTALL_DIRECTORY to install somewhere else.

Use inside BuilderStudio

Open BuilderStudio and choose Agent MIDI > Open Agent MIDI, press Shift-Command-M, or select the piano-keys toolbar button.

The built-in layout maps pads to BuilderStudio modes, submit, approve, cancel, build, test, Codex, and Claude Code actions.

Program controls

Choose Program and select a control. The inspector edits:

• Control type, row, column, and span
• Title, subtitle, and SF Symbol
• MIDI message type, channel, number, and value
• Host, agent CLI, editor, shell, and URL actions
• Agent prompts and command arguments

Edits are saved as JSON layouts in:

~/Library/Application Support/AgentMIDI/Layouts

Skins are loaded from:

~/Library/Application Support/AgentMIDI/Themes

The interface includes buttons that reveal both folders in Finder.

Custom layouts

Copy a JSON layout from Examples/Layouts into the layouts folder and reload layouts. A layout controls the grid size, control placement, MIDI mapping, and command action.

Supported command kinds:

none
host
codex
claudeCode
visualStudioCode
cursor
zed
xcode
shell
openURL

Use ${workspace} or $WORKSPACE inside shell commands, prompts, and arguments to inject the active workspace path.

Custom skins

Copy a JSON skin from Examples/Themes into the themes folder and reload skins. Skins control the deck colors, border colors, corner radii, and spacing.

Interoperability

Agent MIDI uses three layers:

1. Standard CoreMIDI messages for DAWs, automation tools, and MIDI-aware applications.
2. Configurable CLI adapters for coding agents and editors.
3. A macOS distributed notification named com.wundercorp.agentmidi.event with the encoded event JSON in the event user-info field.

A host IDE can embed AgentMIDIDeckView, assign workspaceURL, and provide hostCommandHandler on AgentMIDIController.

Repository split

The AgentMIDI directory is self-contained and can be moved into its own repository. BuilderStudio compiles the shared source files directly from AgentMIDI/Sources/AgentMIDIKit, which keeps the packaged and embedded implementations on one code path.