Musubi

A Clojure DSL that compiles to ZMK and QMK firmware. Write your keyboard layout once, build for anything.

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The Problem

ZMK and QMK are powerful. Their configuration is not.

ZMK asks you to write devicetree. QMK asks you to write C. Both require learning a firmware-specific format before you can place a single key. Changing one behavior means understanding the internals of a specific ecosystem. Sharing a layout between two keyboards is copy-paste.

Musubi replaces all of that with a small set of Clojure macros. You describe what your keyboard does. Musubi handles the rest.

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What It Looks Like

(ns my-keyboards.corne.keyboard
  (:require [musubi.dsl :refer [defproject deflayer defbehavior defkeymap]]))

(defproject my-corne
  :firmware :zmk
  :model    :corne)

(defbehavior thumb-spc
  :type   :hold-tap
  :tap    :kp/spc
  :hold   :kp/lshft
  :flavor :balanced)

(deflayer base
  [:kp/esc  :kp/q  :kp/w  :kp/e  :kp/r  :kp/t]   [:kp/y  :kp/u  :kp/i    :kp/o   :kp/p    :kp/bspc]
  [:kp/tab  :kp/a  :kp/s  :kp/d  :kp/f  :kp/g]   [:kp/h  :kp/j  :kp/k    :kp/l   :kp/semi :kp/ret]
  [:kp/lctl :kp/z  :kp/x  :kp/c  :kp/v  :kp/b]   [:kp/n  :kp/m  :kp/comm :kp/dot :kp/slsh :kp/lalt]
  [:kp/lgui :behavior/trans :behavior/thumb-spc]   [:kp/ret :kp/bspc :kp/del])

(deflayer nav
  [:behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans]   [:behavior/trans :kp/home :kp/pgup :kp/pgdn :kp/end  :behavior/trans]
  [:behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans]   [:behavior/trans :kp/left :kp/up   :kp/down :kp/rght :behavior/trans]
  [:behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans]   [:behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans :behavior/trans]
  [:behavior/trans :behavior/trans :behavior/trans]                                                   [:behavior/trans :behavior/trans :behavior/trans])

(defkeymap my-corne
  :project my-corne
  :layers  [base nav])

That file compiles to a complete ZMK .keymap. Switch :firmware to :qmk and the same file produces keymap.c. No devicetree, no C, no firmware documentation required.

Every macro expands to a plain Clojure map. You can inspect, test, and validate your layout before it ever touches a compiler:

;; In the REPL
base
;; => {:name :base, :bindings [:kp/esc :kp/q :kp/w ...]}

thumb-spc
;; => {:name :thumb-spc, :type :hold-tap, :tap :kp/spc, :hold :kp/lshft, :flavor :balanced}

Your keyboard config is data. Write unit tests against it, diff two layouts programmatically, or build tooling on top. All before compiling a single line of firmware.

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How It Works

[keyboard.clj] -> [parser] -> [universal IR] -> [ZMK backend] -> [.keymap + west build]
                                             -> [QMK backend] -> [keymap.c + qmk compile]

Musubi evaluates your keyboard file, validates the layout against a built-in registry of known keyboards, and dispatches to the correct backend. The firmware toolchain (ZMK's west, QMK's CLI) is installed and managed by Musubi. You never touch it directly.

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Status

Early development. The DSL and IR are being built. Nothing compiles to firmware yet.