kmk_firmware/docs/combos.md

Combos

Combos allow you to assign special functionality to combinations of key presses. The two default behaviors are:

• Chords: match keys in random order, all pressed within 50ms.
• Sequences: match keys in order, pressed within 1s of one another.

You can define combos to listen to any valid KMK key, even internal or functional keys, like HoldTap. When using internal KMK keys, be aware that the order of modules matters.

The result of a combo is another key being pressed/released; if the desired action isn't covered by KMK keys: create your own with make_key and attach corresponding handlers.

Combos may overlap, i.e. share match keys amongst each other.

The optional arguments timeout and per_key_timeout define the time window within which the match has to happen and whether the timeout is renewed after each key press, respectively. These can be customized for every combo individually.

Keycodes

New Keycode	Description
KC.LEADER	a dummy / convenience key for leader key sequences

Example Code

from kmk.keys import KC, make_key
from kmk.modules.combos import Combos, Chord, Sequence
combos = Combos()
keyboard.modules.append(combos)

make_key(
    names=('MYKEY',),
    on_press=lambda: print('I pressed MYKEY'),
)

combos.combos = [
    Chord((KC.A, KC.B), KC.LSFT)
    Chord((KC.A, KC.B, KC.C), KC.LALT)
    Sequence((KC.LEADER, KC.A, KC.B), KC.C)
    Sequence((KC.E, KC.F) KC.MYKEY, timeout=500, per_key_timeout=False)
]