PolyKybd

A split ergonomic keyboard where every key has its own tiny OLED display — driven live by host software that follows your active window.

Start Building How it fits together Get a Kit

Both PolyKybd halves in the dark, each key lit by its own RGB LED in a rainbow gradient running from blue through purple to magenta, with the OLED legends readable through the transparent keycaps.

What makes it unique

72 per-key displays

Every key has its own 72×40 px OLED showing its current function — layers, languages and app overlays are visible at a glance, no guessing. See Context-Aware Overlays.

Fully split ergonomic

Two halves linked over a full-duplex serial cable, so each hand sits exactly where it feels natural. Available as Split72 and the smaller Split42.

Context-aware overlays

The host software tracks your active window and re-labels every key automatically when you switch apps — see how the host does it.

Open hardware & firmware

KiCad schematics, gerbers, STL case files, a QMK firmware fork and the Python host app — every layer is open. Start at Architecture & Ecosystem.

Close-up of transparent keycaps lit in a green-to-purple gradient, each one showing its own OLED legend — letters, an emoji face, a Windows logo and an "Intl" key

A per-key RGB LED sits under the same transparent keycap as the OLED, so one key carries both a legend and a colour — the lighting is a layer of information, not just decoration. (RGB is a Split72 feature; the Split42 has no LED matrix.)

The ecosystem

PolyKybd is built from a handful of open-source repositories that work together:

Component	What it is
PolyKybd hardware	KiCad PCBs, 3D-printable case and key stems, assembly guide
QMK firmware	The keyboard firmware (RP2040) — branch `PolyKybd`, variants `split72` & `split42`
PolyKybdHost	Python host app (Windows / macOS / Linux) — daemon + tray GUI + `polyctl` CLI
Adafruit GFX (fork)	Rendering library + `fontconvert` used to draw icons and text on the displays
PolyKybd CTND	Raspberry Pi hardware-in-the-loop test & CI rig (development infrastructure)

See Architecture & Ecosystem for how these pieces talk to each other.

Browse the docs

Introduction How the keyboard, firmware and host app fit together.

Assembly Parts list, PCB, case, displays, switches and the step-by-step build.

Setup Install PolyKybdHost and flash the firmware onto a finished board.

Using the Keyboard Overlays, languages, glyph scripts, brightness, idle, keymaps and multi-machine use.

Host Software The tray app, the daemon/client model, the polyctl CLI and WinCompose.

Firmware What runs on the RP2040 — keyboard variants and font packs.

Hardware Schematics, electronics and PCB / case modification.

HowTo Add a language or glyph script, create app overlays, build from source, edit the keymap.

Development System model, firmware development, display graphics, the test rig and contributing.

Reference HID protocol, browser-extension privacy and the glossary.

Or jump straight to a task

Want to build one? → Assembly Overview
Already have one? → Install PolyKybdHost
What can it do? → Context-Aware Overlays
Want to customize? → Keymaps & Layers
Want to develop? → Firmware Development
Want the wire details? → HID Protocol Reference

Support the project

PolyKybd is an independent open hardware project. If you find it useful, consider supporting it via Ko-fi or joining the Discord.