diff --git a/examples/Keystrokes/OneShotMetaKeys/OneShotMetaKeys.ino b/examples/Keystrokes/OneShotMetaKeys/OneShotMetaKeys.ino
new file mode 100644
index 00000000..1a155c4a
--- /dev/null
+++ b/examples/Keystrokes/OneShotMetaKeys/OneShotMetaKeys.ino
@@ -0,0 +1,88 @@
+/* -*- mode: c++ -*-
+ * Kaleidoscope-OneShotMetaKeys -- Special OneShot keys
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see .
+ */
+
+#include
+#include
+#include
+#include
+
+// Macros
+enum {
+ TOGGLE_ONESHOT,
+};
+
+// *INDENT-OFF*
+KEYMAPS(
+ [0] = KEYMAP_STACKED
+ (
+ M(TOGGLE_ONESHOT), Key_1, Key_2, Key_3, Key_4, Key_5, OneShot_MetaStickyKey,
+ Key_Backtick, Key_Q, Key_W, Key_E, Key_R, Key_T, Key_Tab,
+ Key_PageUp, Key_A, Key_S, Key_D, Key_F, Key_G,
+ Key_PageDown, Key_Z, Key_X, Key_C, Key_V, Key_B, Key_Escape,
+
+ OSM(LeftControl), Key_Backspace, OSM(LeftGui), OSM(LeftShift),
+ Key_Meh,
+
+ OneShot_ActiveStickyKey, Key_6, Key_7, Key_8, Key_9, Key_0, ___,
+ Key_Enter, Key_Y, Key_U, Key_I, Key_O, Key_P, Key_Equals,
+ Key_H, Key_J, Key_K, Key_L, Key_Semicolon, Key_Quote,
+ ___, Key_N, Key_M, Key_Comma, Key_Period, Key_Slash, Key_Minus,
+
+ Key_RightShift, Key_RightAlt, Key_Spacebar, Key_RightControl,
+ OSL(1)),
+
+ [1] = KEYMAP_STACKED
+ (
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+
+ ___, ___, ___, ___,
+ ___,
+
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ Key_UpArrow, Key_DownArrow, Key_LeftArrow, Key_RightArrow,___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+
+ ___, ___, ___, ___,
+ ___),
+)
+// *INDENT-ON*
+
+void macroToggleOneShot() {
+ OneShot.toggleAutoOneShot();
+}
+
+const macro_t *macroAction(uint8_t macro_id, KeyEvent &event) {
+ if (macro_id == TOGGLE_ONESHOT) {
+ macroToggleOneShot();
+ }
+
+ return MACRO_NONE;
+}
+
+KALEIDOSCOPE_INIT_PLUGINS(OneShot, OneShotMetaKeys, Macros);
+
+void setup() {
+ Kaleidoscope.setup();
+}
+
+void loop() {
+ Kaleidoscope.loop();
+}
diff --git a/examples/Keystrokes/OneShotMetaKeys/sketch.json b/examples/Keystrokes/OneShotMetaKeys/sketch.json
new file mode 100644
index 00000000..884ed009
--- /dev/null
+++ b/examples/Keystrokes/OneShotMetaKeys/sketch.json
@@ -0,0 +1,6 @@
+{
+ "cpu": {
+ "fqbn": "keyboardio:avr:model01",
+ "port": ""
+ }
+}
diff --git a/plugins/Kaleidoscope-OneShotMetaKeys/README.md b/plugins/Kaleidoscope-OneShotMetaKeys/README.md
new file mode 100644
index 00000000..9b192e8e
--- /dev/null
+++ b/plugins/Kaleidoscope-OneShotMetaKeys/README.md
@@ -0,0 +1,56 @@
+# OneShot Meta Keys
+
+This plugin provides support for two special OneShot keys:
+`OneShot_MetaStickyKey` & `OneShot_ActiveStickyKey`, each of which can be used
+to make any key on the keyboard (not just modifiers and layer shift keys)
+"sticky", so that they remain active even after the key has been released.
+These are both `Key` values that can be used as entries in your sketch's keymap.
+
+Any keys made sticky in this way can be released just like OneShot modifier
+keys, by tapping them again to cancel the effect.
+
+## The `OneShot_MetaStickyKey`
+
+This special OneShot key behaves like other OneShot keys, but its affect is to
+make the next key pressed sticky. Tap `OneShot_MetaStickyKey`, then tap `X`, and
+`X` will become sticky. Tap `X` again to deactivate it.
+
+Double-tapping `OneShot_MetaStickyKey` will make it sticky, just like any other
+OneShot key. A third tap will release the key.
+
+## The `OneShot_ActiveStickyKey`
+
+This special key doesn't act like a OneShot key, but instead makes any key(s)
+currently held (or otherwise active) sticky. Press (and hold) `X`, tap
+`OneShot_ActiveStickyKey`, then release `X`, and `X` will stay active until it
+is tapped again to deactivate it.
+
+## Using the plugin
+
+To use the plugin, just include one of the two special OneShot keys somewhere in
+your keymap, and add both OneShot and OneShotMetaKeys to your sketch:
+
+```c++
+#include
+#include
+
+// somewhere in the keymap...
+OneShot_MetaStickyKey, OneShot_ActiveStickyKey
+
+KALEIDOSCOPE_INIT_PLUGINS(OneShot, OneShotMetaKeys);
+```
+
+Important note: OneShotMetaKeys _must_ be registered after OneShot in
+`KALEIDOSCOPE_INIT_PLUGINS()` in order to function properly.
+
+## Dependencies
+
+* [Kaleidoscope-OneShot](Kaleidoscope-OneShot.md)
+* [Kaleidoscope-Ranges](Kaleidoscope-Ranges.md)
+
+## Further reading
+
+Starting from the [example][plugin:example] is the recommended way of getting
+started with the plugin.
+
+ [plugin:example]: /examples/Keystrokes/OneShotMetaKeys/OneShotMetaKeys.ino
diff --git a/plugins/Kaleidoscope-OneShotMetaKeys/library.properties b/plugins/Kaleidoscope-OneShotMetaKeys/library.properties
new file mode 100644
index 00000000..28d5cb9d
--- /dev/null
+++ b/plugins/Kaleidoscope-OneShotMetaKeys/library.properties
@@ -0,0 +1,7 @@
+name=Kaleidoscope-OneShotMetaKeys
+version=0.0.0
+sentence=OneShot_ActiveStickyKey & OneShot_MetaStickyKey
+maintainer=Kaleidoscope's Developers
+url=https://github.com/keyboardio/Kaleidoscope
+author=Keyboardio
+paragraph=
diff --git a/plugins/Kaleidoscope-OneShotMetaKeys/src/Kaleidoscope-OneShotMetaKeys.h b/plugins/Kaleidoscope-OneShotMetaKeys/src/Kaleidoscope-OneShotMetaKeys.h
new file mode 100644
index 00000000..5266fc62
--- /dev/null
+++ b/plugins/Kaleidoscope-OneShotMetaKeys/src/Kaleidoscope-OneShotMetaKeys.h
@@ -0,0 +1,20 @@
+/* -*- mode: c++ -*-
+ * Kaleidoscope-OneShot -- One-shot modifiers and layers
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see .
+ */
+
+#pragma once
+
+#include
diff --git a/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.cpp b/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.cpp
new file mode 100644
index 00000000..e8765933
--- /dev/null
+++ b/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.cpp
@@ -0,0 +1,94 @@
+/* -*- mode: c++ -*-
+ * Kaleidoscope-OneShot -- One-shot modifiers and layers
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see .
+ */
+
+#include
+
+#include
+#include
+
+#include "kaleidoscope/KeyAddr.h"
+#include "kaleidoscope/key_defs.h"
+#include "kaleidoscope/KeyEvent.h"
+#include "kaleidoscope/keyswitch_state.h"
+#include "kaleidoscope/LiveKeys.h"
+
+namespace kaleidoscope {
+namespace plugin {
+
+// ============================================================================
+// Public interface
+
+// ----------------------------------------------------------------------------
+// Plugin hook functions
+
+EventHandlerResult OneShotMetaKeys::onNameQuery() {
+ return ::Focus.sendName(F("OneShotMetaKeys"));
+}
+
+EventHandlerResult OneShotMetaKeys::onKeyEvent(KeyEvent &event) {
+ // Ignore key release and injected events.
+ if (keyToggledOff(event.state) || event.state & INJECTED)
+ return EventHandlerResult::OK;
+
+ // Make all held keys sticky if `OneShot_ActiveStickyKey` toggles on.
+ if (event.key == OneShot_ActiveStickyKey) {
+ // Note: we don't need to explicitly skip the key the active sticky key
+ // itself (i.e. `event.addr`), because its entry in `live_keys[]` has not
+ // yet been inserted at this point.
+ for (KeyAddr addr : KeyAddr::all()) {
+ // Get the entry from the keyboard state array.
+ Key key = live_keys[addr];
+ // Skip idle and masked entries.
+ if (key == Key_Inactive || key == Key_Masked) {
+ continue;
+ }
+ // Make everything else sticky.
+ ::OneShot.setSticky(addr);
+ }
+ return EventHandlerResult::OK;
+ }
+
+ // If there's an active meta-sticky key, we need to make newly-pressed keys
+ // sticky, unless they were already active, in which case we let OneShot
+ // release them from the "sticky" state.
+ if (isMetaStickyActive() &&
+ live_keys[event.addr] != event.key) {
+ ::OneShot.setSticky(event.addr);
+ return EventHandlerResult::OK;
+ }
+
+ // If a previously-inactive meta-sticky key was just pressed, we have OneShot
+ // put it in the "pending" state so it will act like a OneShot key.
+ if (event.key == OneShot_MetaStickyKey &&
+ live_keys[event.addr] != OneShot_MetaStickyKey) {
+ ::OneShot.setPending(event.addr);
+ }
+ return EventHandlerResult::OK;
+}
+
+bool OneShotMetaKeys::isMetaStickyActive() {
+ for (Key key : live_keys.all()) {
+ if (key == OneShot_MetaStickyKey)
+ return true;
+ }
+ return false;
+}
+
+} // namespace plugin
+} // namespace kaleidoscope
+
+kaleidoscope::plugin::OneShotMetaKeys OneShotMetaKeys;
diff --git a/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.h b/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.h
new file mode 100644
index 00000000..5f5a4f3a
--- /dev/null
+++ b/plugins/Kaleidoscope-OneShotMetaKeys/src/kaleidoscope/plugin/OneShotMetaKeys.h
@@ -0,0 +1,52 @@
+/* -*- mode: c++ -*-
+ * Kaleidoscope-OneShot -- One-shot modifiers and layers
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see .
+ */
+
+#pragma once
+
+#include
+#include
+
+#include "kaleidoscope/event_handler_result.h"
+#include "kaleidoscope/key_defs.h"
+#include "kaleidoscope/KeyEvent.h"
+#include "kaleidoscope/plugin.h"
+
+// ----------------------------------------------------------------------------
+// Key constants
+constexpr Key OneShot_MetaStickyKey {kaleidoscope::ranges::OS_META_STICKY};
+constexpr Key OneShot_ActiveStickyKey {kaleidoscope::ranges::OS_ACTIVE_STICKY};
+
+namespace kaleidoscope {
+namespace plugin {
+
+class OneShotMetaKeys : public kaleidoscope::Plugin {
+ public:
+ // --------------------------------------------------------------------------
+ // Plugin hook functions
+
+ EventHandlerResult onNameQuery();
+ EventHandlerResult onKeyEvent(KeyEvent &event);
+
+ private:
+ static bool isMetaStickyActive();
+
+};
+
+} // namespace plugin
+} // namespace kaleidoscope
+
+extern kaleidoscope::plugin::OneShotMetaKeys OneShotMetaKeys;
diff --git a/tests/plugins/OneShot/meta-keys/meta-keys.ino b/tests/plugins/OneShot/meta-keys/meta-keys.ino
new file mode 100644
index 00000000..56b47042
--- /dev/null
+++ b/tests/plugins/OneShot/meta-keys/meta-keys.ino
@@ -0,0 +1,53 @@
+/* -*- mode: c++ -*-
+ * Copyright (C) 2021 Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see .
+ */
+
+#include
+#include
+#include
+
+// *INDENT-OFF*
+KEYMAPS(
+ [0] = KEYMAP_STACKED
+ (
+ OneShot_MetaStickyKey, OneShot_ActiveStickyKey, ___, ___, ___, ___, ___,
+ Key_A, Key_B, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___,
+ ___,
+
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___, ___, ___, ___,
+ ___, ___, ___, ___,
+ ___
+ ),
+)
+// *INDENT-ON*
+
+KALEIDOSCOPE_INIT_PLUGINS(OneShot, OneShotMetaKeys);
+
+void setup() {
+ Kaleidoscope.setup();
+ OneShot.setTimeout(50);
+ OneShot.setHoldTimeout(20);
+ OneShot.setDoubleTapTimeout(20);
+}
+
+void loop() {
+ Kaleidoscope.loop();
+}
diff --git a/tests/plugins/OneShot/meta-keys/sketch.json b/tests/plugins/OneShot/meta-keys/sketch.json
new file mode 100644
index 00000000..8cc86922
--- /dev/null
+++ b/tests/plugins/OneShot/meta-keys/sketch.json
@@ -0,0 +1,6 @@
+{
+ "cpu": {
+ "fqbn": "keyboardio:virtual:model01",
+ "port": ""
+ }
+}
diff --git a/tests/plugins/OneShot/meta-keys/test.ktest b/tests/plugins/OneShot/meta-keys/test.ktest
new file mode 100644
index 00000000..d8b883d8
--- /dev/null
+++ b/tests/plugins/OneShot/meta-keys/test.ktest
@@ -0,0 +1,325 @@
+VERSION 1
+
+KEYSWITCH OS_META 0 0
+KEYSWITCH OS_ACTIVE 0 1
+KEYSWITCH A 1 0
+KEYSWITCH B 1 1
+
+# ==============================================================================
+NAME OneShot meta sticky
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot meta sticky rollover
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot meta sticky overlap
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot meta sticky overlap to rollover
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot meta sticky sticky
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+PRESS B
+RUN 1 cycle
+EXPECT keyboard-report Key_A Key_B
+
+RUN 4 ms
+RELEASE B
+RUN 1 cycle
+
+RUN 4 ms
+PRESS OS_META
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_META
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report Key_B
+
+RUN 4 ms
+PRESS B
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE B
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot active sticky
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+PRESS OS_ACTIVE
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_ACTIVE
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms
+
+# ==============================================================================
+NAME OneShot active sticky two keys
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+EXPECT keyboard-report Key_A
+
+RUN 4 ms
+PRESS B
+RUN 1 cycle
+EXPECT keyboard-report Key_A Key_B
+
+RUN 4 ms
+PRESS OS_ACTIVE
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE OS_ACTIVE
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE B
+RUN 1 cycle
+
+RUN 4 ms
+PRESS A
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE A
+RUN 1 cycle
+EXPECT keyboard-report Key_B
+
+RUN 4 ms
+PRESS B
+RUN 1 cycle
+
+RUN 4 ms
+RELEASE B
+RUN 1 cycle
+EXPECT keyboard-report empty
+
+RUN 5 ms