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Sticky Keys

Sticky keys enable you to have keys that stay pressed for a certain time or until another key is pressed and released. If the timeout expires or other keys are pressed, and the sticky key wasn't released, it is handled as a regular key being held. Sticky keys are sometimes also referred to as "one shot keys".

Enable Sticky Keys

from kmk.modules.sticky_keys import StickyKeys
sticky_keys = StickyKeys()
# optional: set a custom release timeout in ms (default: 1000ms)
# sticky_keys = StickyKeys(release_after=5000)
keyboard.modules.append(sticky_keys)

Keycodes

Keycode Aliases Description
KC.SK(KC.ANY) KC.STICKY make a sticky version of KC.ANY

KC.STICKY accepts any valid key code as argument, including modifiers and KMK internal keys like momentary layer shifts.

Custom Sticky Behavior

The full sticky key signature is as follows:

KC.SK(
    KC.ANY,              # the key to made sticky
    defer_release=False  # when to release the key
    retap_cancel=True    # repeated tap releases the key
)

defer_release

If False (default): release sticky key after the first interrupting key releases. If True: stay sticky until all keys are released. Useful when combined with non-sticky modifiers, layer keys, etc...

repeat_cancel

If True (default): Repeated tap releases the key and refreshes timeout. If False: Repeated tap refreshes the timeout.

Sticky Stacks

Sticky keys can be stacked, i.e. tapping a sticky key within the release timeout of another will reset the timeout off all previously tapped sticky keys and "stack" their effects. In this example if you tap SK_LCTL and then SK_LSFT followed by KC.TAB, the output will be ctrl+shift+tab.

SK_LCTL = KC.SK(KC.LCTL)
SK_LSFT = KC.SK(KC.LSFT)

keyboard.keymap = [[SK_LSFT, SK_LCTL, KC.TAB]]