Third-party configuration app for the MX Master 3S and MX Keys S on Linux. It brings full device configuration to GNOME, KDE and other desktops: button and key assignments, gestures, thumb wheel actions, SmartShift, DPI, smart backlighting, Easy-Switch and per-application profiles.
LogiMX is an independent project. It is not affiliated with, endorsed by, or supported by the manufacturer of these devices. The device pictures in the app are the author's own and are part of this repository under its license.
A native agent owns the devices in the background; the desktop UI talks to it over a local socket.
agent/ C++20 agent. HID++ 1.0/2.0 over hidraw, uinput for actions, X11 focus tracking,
JSON RPC over a UNIX socket. No runtime dependencies beyond libc, libstdc++, libX11.
ui/ Electron UI, plain HTML/CSS/JS, talks to the agent over the socket.
logimx/ Python implementation of the same agent (same RPC and config schema). It was
written first to validate the protocol against real hardware and is kept as a
reference and for scripting.
udev/ hidraw and uinput access rule.
systemd/ user service unit for the agent.
The agent talks HID++ directly to the receiver or to a Bluetooth device, diverts the controls you customise so the device sends HID++ events instead of the stock key, and synthesises the desktop action through a virtual input device. That works the same under X11 and Wayland because it sits below the compositor.
Mouse (MX Master 3S)
- Assign any action to the middle, back, forward, gesture and mode shift buttons, with numbered callouts on a photo of the device
- Gestures: tap plus four swipe directions on a gesture pad, one-shot or continuous, adjustable sensitivity, any movement-capable button can be the gesture button
- Thumb wheel: horizontal or vertical scroll, zoom, volume, tabs, workspaces, brightness, direction and speed
- DPI 200 to 8000, desktop pointer speed, SmartShift on/off and sensitivity, a SmartShift toggle action, smooth scrolling, natural scroll direction
- Battery with 7-day history, firmware, serial, Easy-Switch host cards with one-click switching
Keyboard (MX Keys S)
- Function row grid and special keys (calculator, capture, menu, lock, dictation, emoji, mic mute) with clickable keys on a photo of the keyboard
- Built-in emoji picker: the Emoji key opens a searchable picker at the pointer (categories, recents, keyboard navigation), Enter pastes into the focused app
- Smart backlight: on/off, automatic or manual level, hands-away, hands-present and on-power timers
- Battery, firmware, Easy-Switch
Everything
- Adwaita-style window with four themes: Light, Dark, Ubuntu, Ubuntu dark
- Action picker with categories, search, a keystroke recorder, shell commands, typed text, open URL or folder, launch any installed application
- Per-application profiles with an override view (overridden vs inherited per control), suggestions from installed applications
- On-screen overlays when a key changes device state: microphone mute, SmartShift mode, backlight level, Easy-Switch host, DPI; position, duration and per-event switches
- Tray indicator with battery levels, Easy-Switch, pause diversion; desktop notifications for low battery (threshold configurable) and connect/disconnect
- Global shortcuts: Super+Alt+1..3 switch host, Super+Alt+O toggles overlays, Super+Alt+P pauses diversion
- Bolt pairing wizard with passkey confirmation, first-run wizard (permissions with pkexec udev install, devices, GNOME / macOS-like / Windows-like presets)
- Backup & sync: automatic daily backups, manual backups, restore, export/import, reset, read settings back from the device
- Settings: start at login (systemd user service), tray, close-to-tray, start hidden, appearance, update check; About with diagnostics log, export and copy
- Hot plug through inotify; settings re-applied when a device reconnects
| Gestures | Point and scroll |
|---|---|
 |
 |
| Keyboard | Backlight |
|---|---|
 |
 |
| Action picker | Easy-Switch |
|---|---|
 |
 |
| Battery & info | Notifications and overlays |
|---|---|
 |
 |
| Emoji picker | Tray status panel |
|---|---|
 |
 |
| First run | Dark theme |
|---|---|
 |
 |
| Ubuntu theme | Applications |
|---|---|
 |
 |
Packages are attached to each release. They are built on GitHub's runners by the release workflow every time a version tag is pushed, so each asset can be traced back to a public build log.
Debian / Ubuntu (.deb): agent, CLI, udev rule, systemd user unit, desktop entry and the app.
sudo apt install ./logimx_0.3.0_amd64.deb
systemctl --user enable --now logimx # agent for the current session (automatic after the next login)
logimx # or launch LogiMX from the app grid
AppImage: one file, no installation. The app starts the bundled agent itself and the first-run wizard installs the udev rule with pkexec.
chmod +x LogiMX-0.3.0-x86_64.AppImage
./LogiMX-0.3.0-x86_64.AppImage
Build the packages yourself with packaging/deb/build.sh and cd ui && npm run dist:appimage.
- Linux with the kernel's HID++ receiver drivers (built into any mainstream distro)
- g++ 11 or newer, cmake, ninja, libx11-dev
- node 18 or newer for the UI
- Read and write access to
/dev/hidraw*for the receiver and to/dev/uinput(udev/60-logimx.rules, or the rule that ships with Solaar)
Stop other tools that divert the same buttons (Solaar, logid) while LogiMX runs, otherwise
two programs fight over the device. On GNOME the tray icon needs the AppIndicator extension
(gnome-shell-extension-appindicator), which Ubuntu ships enabled.
./run-agent.sh -v # terminal 1: builds on first run, logs to stderr
./run-ui.sh # terminal 2: window and tray icon (--hidden starts in the tray)
./agent/build/logimxctl devices
Install for the current user (agent in ~/.local/bin, systemd user service):
./install.sh
sudo cp udev/60-logimx.rules /etc/udev/rules.d/ && sudo udevadm control --reload && sudo udevadm trigger
Use "Pair a device" in the app menu. If the device you are pairing is also known to Bluetooth on the same machine, the pairing can fail a few seconds after the passcode is typed: BlueZ keeps trying to reconnect to it and that traffic shares the 2.4 GHz band with the Bolt handshake. Pair with the adapter switched off instead:
./pair-bolt.sh
It powers Bluetooth down, holds discovery open until the device appears, shows the passcode, and restores Bluetooth on exit.
logimxctl devices
logimxctl set b034 dpi 1600
logimxctl set b034 smartshift.threshold 20
logimxctl set b378 backlight.mode manual
logimxctl set b378 backlight.level 5
logimxctl assign b034 buttons 195 gesture_windows
logimxctl assign b034 thumbwheel - volume_wheel
logimxctl assign b378 keys 264 emoji_picker
logimxctl host b378 2
logimxctl presets
Configuration lives in ~/.config/logimx/config.json. Device ids are the product ids
(b034 MX Master 3S, b378 MX Keys S), controls are HID++ control ids.
Tested on Ubuntu 24.04 with GNOME on X11, MX Master 3S and MX Keys S on a Bolt receiver. Bluetooth connections work the same way as the receiver (tested with the MX Keys S paired directly). GNOME on Wayland tracks the focused application through the Shell introspection interface when it is enabled.
Planned: more MX devices, pairing UI, KDE and Sway focus tracking, packaging.
- Solaar: device manager for Unifying and Bolt receivers, broad HID++ feature coverage
- logiops: daemon with gestures and SmartShift, configured through a text file
- libratbag and Piper: DPI and button configuration for gaming mice
LogiMX differs by pairing a native agent with a full desktop UI, per-application profiles and a gesture editor, so the day-to-day experience matches what users get on Windows and macOS.
MX Master 3S Linux, MX Keys S Linux, MX Master gestures Linux, thumb wheel Linux, SmartShift Linux, MX Keys backlight Linux, Bolt receiver Linux, Unifying receiver Linux, HID++ configuration, GNOME, KDE, Wayland, X11, uinput, hidraw.
MIT