LayerLens
A native macOS overlay that mirrors the live layer state of your QMK or Vial keyboard. Pin it on screen, watch it flash on every layer change, theme it like the rest of your battlestation. Free, open source, signed and notarised.
LayerLens runs in your menu bar, sees every layer your keyboard broadcasts, and surfaces it in a panel that's actually pleasant to look at. No daemon to babysit, no Electron.
A non-activating panel that floats above your work, fades in on every layer transition, and gets out of your way. Pin it for a live view; let it flash if you only need a glance. Per-board theming, custom labels, your choice of font.
Rename labels, browse layers, set the layout source, see live stats — protocol version, layer count, whether the firmware module is responding. Plug a different board in and the window re-shapes itself to match.
All the programmer favourites — Dracula, Tokyo Night, Solarized, Nord, Monokai, Gruvbox, One Dark — built in. Each colour role (regular, modifier, layer, special, label) is independently editable, with a live preview that paints onto your wallpaper while you fiddle.
LayerLens reads layer events directly from your firmware over Raw HID. Both ends need to be on board.
layerlens_notify module flashed — required for live layer events
VIA's protocol exposes the keymap, but doesn't expose live layer
changes. layerlens_notify is a 60-line QMK module
that fixes that. Two pure functions, you wire them in.
Talks to any QMK board with the standard 0xFF60 / 0x61 Raw HID interface.
Auto-fetches the layout from the firmware on protocol v9 boards.
Plain QMK works too. Drop in the firmware module for live layer events.
Copy firmware/layerlens_notify/ from the repo to
your QMK userspace. Add it to your keymap:
{
"modules": ["fireball1725/layerlens_notify"]
}Chain it from your layer_state_set_user:
layer_state_t layer_state_set_user(layer_state_t state) {
return layer_state_set_layerlens_notify(state);
}One snippet, pick what matches your firmware:
bool via_command_kb(uint8_t *data, uint8_t length) {
return layerlens_notify_handle_command(data, length);
}void raw_hid_receive(uint8_t *data, uint8_t length) {
if (layerlens_notify_handle_command(data, length)) return;
}That's it. Open LayerLens; the Configure window's Live stat flips to Yes and the overlay starts flashing on every layer change.
Read the wire-format spec ↗