Detection, done like sync:

- ESC[?u goes to every VT100-like terminal at attach, whatever the options. - A reply turns on a new kittykeys terminal feature. Users can force it on or off with terminal-features kittykeys, including kittykeys@ to turn it off. - Changing extended-keys now takes effect immediately for attached clients (options.c). Use, per client, when extended-keys is on: Kitty for clients that have kittykeys, modifyOtherKeys for clients with extkeys, VT10x otherwise. Pane side: - Applications can request either protocol; Kitty wins if one asks for both. - Each application gets what it asked for, whichever client typed the key. - ESC[?u is answered truthfully. - The per-client gate is gone. window.c and popup.c are simply master's versions again. extended-keys always is back to its master meaning, forcing modifyOtherKeys mode 1 only. Forcing Kitty on every program would have sent bash ESC[97;5u for Ctrl-A. extended-keys-format kitty is still accepted, but now behaves the same as csi-u.
Add a test for Kitty keyboard protocol input parsing
2026-09-19 11:28:08 +00:00 · 2026-09-19 07:32:57 +01:00 · 2026-09-17 06:16:11 +01:00 · 2026-09-17 06:00:13 +01:00 · 2026-09-15 06:14:43 +01:00 · 2026-09-15 06:11:25 +01:00
33 changed files with 1682 additions and 2101 deletions
--- a/12
+++ b/12
@@ -111,6 +111,18 @@ CHANGES FROM 3.7c TO 3.8

 * Change show-options and show-hooks to use formats and add a -F flag to each.

+* Add support for the Kitty keyboard protocol. When extended-keys is on,
+  tmux uses it with terminals which support it, detected when a client
+  attaches or set with a new kittykeys terminal feature, and standard
+  extended keys or VT10x keys with other terminals, so terminals with
+  different capabilities may be attached at the same time. Programs inside
+  tmux may ask for either the Kitty protocol or modifyOtherKeys and get keys
+  in the form they asked for. The Kitty protocol can report the Super and
+  Hyper modifiers (key name prefixes s- and H-).
+
+* Add a client_key_mode format giving the extended key reporting mode in
+  use for a client, alongside the existing pane_key_mode for a pane.
+
 * Allow individual terminal features to be disabled by adding @ to their names
  in terminal-features, and add a utf8 feature for terminals which support
  UTF-8 output.
--- a/Makefile.am
+++ b/Makefile.am
@@ -171,6 +171,7 @@ dist_tmux_SOURCES = \
 	grid.c \
 	hooks.c \
 	hyperlinks.c \
+	input-kitty.c \
 	input-keys.c \
 	input.c \
 	job.c \
@@ -212,6 +213,7 @@ dist_tmux_SOURCES = \
 	tty-acs.c \
 	tty-draw.c \
 	tty-features.c \
+	tty-kitty.c \
 	tty-keys.c \
 	tty-term.c \
 	tty.c \
--- a/cmd-copy-mode.c
+++ b/cmd-copy-mode.c
@@ -30,8 +30,8 @@ const struct cmd_entry cmd_copy_mode_entry = {
 	.name = "copy-mode",
 	.alias = NULL,

-	.args = { "UcdekHMqSs:t:u", 0, 0, NULL },
-	.usage = "[-UcdekHMqSu] [-s src-pane] " CMD_TARGET_PANE_USAGE,
+	.args = { "dekHMqSs:t:u", 0, 0, NULL },
+	.usage = "[-dekHMqSu] [-s src-pane] " CMD_TARGET_PANE_USAGE,

 	.source =  { 's', CMD_FIND_PANE, 0 },
 	.target = { 't', CMD_FIND_PANE, 0 },
--- a/format.c
+++ b/format.c
@@ -1617,6 +1617,41 @@ format_cb_client_height(struct format_tree *ft)
 	return (NULL);
 }

+/* Callback for client_key_mode. */
+static void *
+format_cb_client_key_mode(struct format_tree *ft)
+{
+	struct client	*c = ft->c;
+	const char	*mode;
+	char		*s;
+	int		 kitty, eks;
+
+	if (c == NULL || (~c->tty.flags & TTY_STARTED))
+		return (NULL);
+
+	if (c->tty.flags & TTY_KKBPUSHED) {
+		xasprintf(&s, "Kitty %u", c->tty.kitty_keys);
+		return (s);
+	}
+
+	/* This mirrors the choice made in tty_update_features(). */
+	kitty = ((c->tty.term->flags & TERM_KITTYKEYS) != 0);
+	eks = (options_get_number(global_options, "extended-keys") != 0);
+	if (kitty)
+		eks = 0;
+	if (eks && tty_term_has(c->tty.term, TTYC_ENEKS))
+		mode = "Ext";
+	else
+		mode = "VT10x";
+
+	/* The terminal supports Kitty keys but they are not in use. */
+	if (kitty) {
+		xasprintf(&s, "%s (Kitty)", mode);
+		return (s);
+	}
+	return (xstrdup(mode));
+}
+
 /* Callback for client_key_table. */
 static void *
 format_cb_client_key_table(struct format_tree *ft)
@@ -2487,7 +2522,14 @@ format_cb_pane_unseen_changes(struct format_tree *ft)
 static void *
 format_cb_pane_key_mode(struct format_tree *ft)
 {
+	char	*s;
+
 	if (ft->wp != NULL && ft->wp->screen != NULL) {
+		if (ft->wp->screen->kitty_keys.flags != 0) {
+			xasprintf(&s, "Kitty %u",
+			    ft->wp->screen->kitty_keys.flags);
+			return (s);
+		}
 		switch (ft->wp->screen->mode & EXTENDED_KEY_MODES) {
 		case MODE_KEYS_EXTENDED:
 			return (xstrdup("Ext 1"));
@@ -3642,6 +3684,9 @@ static const struct format_table_entry format_table[] = {
 	{ "client_height", FORMAT_TABLE_STRING,
 	  format_cb_client_height
 	},
+	{ "client_key_mode", FORMAT_TABLE_STRING,
+	  format_cb_client_key_mode
+	},
 	{ "client_key_table", FORMAT_TABLE_STRING,
 	  format_cb_client_key_table
 	},
--- a/grid.c
+++ b/grid.c
@@ -1760,8 +1760,6 @@ grid_line_flags_string(int flags)
 		strlcat(s, "START_OUTPUT,", sizeof s);
 	if (flags & GRID_LINE_END_OUTPUT)
 		strlcat(s, "END_OUTPUT,", sizeof s);
-	if (flags & GRID_LINE_END_OUTPUT_STATUS)
-		strlcat(s, "END_OUTPUT_STATUS,", sizeof s);
 	if (flags & GRID_LINE_HYPERLINK)
 		strlcat(s, "HYPERLINK,", sizeof s);
 	if (*s == '\0')
--- a/input-keys.c
+++ b/input-keys.c
@@ -464,7 +464,8 @@ input_key_extended(struct bufferevent *bev, key_code key)
 	} else
 		key &= KEYC_MASK_KEY;

-	if (options_get_number(global_options, "extended-keys-format") == 1)
+	if (options_get_number(global_options, "extended-keys-format") ==
+	    EXTENDED_KEYS_XTERM)
 		xsnprintf(tmp, sizeof tmp, "\033[27;%c;%llu~", modifier, key);
 	else
 		xsnprintf(tmp, sizeof tmp, "\033[%llu;%cu", key, modifier);
@@ -588,6 +589,10 @@ input_key(struct screen *s, struct bufferevent *bev, key_code key)
 		return (0);
 	}

+	/* Kitty keys take precedence if the application asked for them. */
+	if (input_key_kitty(s, bev, key) == 0)
+		return (0);
+
 	/* Is this backspace? */
 	if ((key & KEYC_MASK_KEY) == KEYC_BSPACE) {
 		newkey = options_get_number(global_options, "backspace");
@@ -677,6 +682,10 @@ input_key(struct screen *s, struct bufferevent *bev, key_code key)
 		log_debug("%s: ignoring key 0x%llx", __func__, key);
 		return (0);
 	}
+	if (key & (KEYC_SUPER|KEYC_HYPER))
+		return (input_key_vt10x(bev, key));
+	if (s->kitty_keys.flags & KITTY_KEY_SUPPORTED)
+		return (input_key_vt10x(bev, key));

 	/*
 	 * No builtin key sequence; construct an extended key sequence
--- a/input-kitty.c
+++ b/input-kitty.c
@@ -0,0 +1,313 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2026 Michael Grant <mgrant@grant.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <string.h>
+#include <wchar.h>
+
+#include "tmux.h"
+
+/* Track pane keyboard state and encode keys for applications. */
+
+struct input_kitty_key {
+	key_code	 key;
+	u_int		 number;
+	char		 final;
+};
+
+static const struct input_kitty_key input_kitty_keys[] = {
+	{ C0_ESC, 27, 'u' },
+	{ C0_CR, 13, 'u' },
+	{ C0_HT, 9, 'u' },
+	{ KEYC_BSPACE, 127, 'u' },
+	{ KEYC_IC, 2, '~' },
+	{ KEYC_DC, 3, '~' },
+	{ KEYC_LEFT, 1, 'D' },
+	{ KEYC_RIGHT, 1, 'C' },
+	{ KEYC_UP, 1, 'A' },
+	{ KEYC_DOWN, 1, 'B' },
+	{ KEYC_PPAGE, 5, '~' },
+	{ KEYC_NPAGE, 6, '~' },
+	{ KEYC_HOME, 1, 'H' },
+	{ KEYC_END, 1, 'F' },
+	{ KEYC_F1, 1, 'P' },
+	{ KEYC_F2, 1, 'Q' },
+	{ KEYC_F3, 13, '~' },
+	{ KEYC_F4, 1, 'S' },
+	{ KEYC_F5, 15, '~' },
+	{ KEYC_F6, 17, '~' },
+	{ KEYC_F7, 18, '~' },
+	{ KEYC_F8, 19, '~' },
+	{ KEYC_F9, 20, '~' },
+	{ KEYC_F10, 21, '~' },
+	{ KEYC_F11, 23, '~' },
+	{ KEYC_F12, 24, '~' },
+	{ KEYC_CAPSLOCK, 57358, 'u' },
+	{ KEYC_SCROLLLOCK, 57359, 'u' },
+	{ KEYC_NUMLOCK, 57360, 'u' },
+	{ KEYC_PRINTSCREEN, 57361, 'u' },
+	{ KEYC_PAUSE, 57362, 'u' },
+	{ KEYC_MENU, 57363, 'u' },
+	{ KEYC_F13, 57376, 'u' },
+	{ KEYC_F14, 57377, 'u' },
+	{ KEYC_F15, 57378, 'u' },
+	{ KEYC_F16, 57379, 'u' },
+	{ KEYC_F17, 57380, 'u' },
+	{ KEYC_F18, 57381, 'u' },
+	{ KEYC_F19, 57382, 'u' },
+	{ KEYC_F20, 57383, 'u' },
+	{ KEYC_F21, 57384, 'u' },
+	{ KEYC_F22, 57385, 'u' },
+	{ KEYC_F23, 57386, 'u' },
+	{ KEYC_F24, 57387, 'u' },
+	{ KEYC_F25, 57388, 'u' },
+	{ KEYC_F26, 57389, 'u' },
+	{ KEYC_F27, 57390, 'u' },
+	{ KEYC_F28, 57391, 'u' },
+	{ KEYC_F29, 57392, 'u' },
+	{ KEYC_F30, 57393, 'u' },
+	{ KEYC_F31, 57394, 'u' },
+	{ KEYC_F32, 57395, 'u' },
+	{ KEYC_F33, 57396, 'u' },
+	{ KEYC_F34, 57397, 'u' },
+	{ KEYC_F35, 57398, 'u' },
+	{ KEYC_KP_ZERO|KEYC_KEYPAD, 57399, 'u' },
+	{ KEYC_KP_ONE|KEYC_KEYPAD, 57400, 'u' },
+	{ KEYC_KP_TWO|KEYC_KEYPAD, 57401, 'u' },
+	{ KEYC_KP_THREE|KEYC_KEYPAD, 57402, 'u' },
+	{ KEYC_KP_FOUR|KEYC_KEYPAD, 57403, 'u' },
+	{ KEYC_KP_FIVE|KEYC_KEYPAD, 57404, 'u' },
+	{ KEYC_KP_SIX|KEYC_KEYPAD, 57405, 'u' },
+	{ KEYC_KP_SEVEN|KEYC_KEYPAD, 57406, 'u' },
+	{ KEYC_KP_EIGHT|KEYC_KEYPAD, 57407, 'u' },
+	{ KEYC_KP_NINE|KEYC_KEYPAD, 57408, 'u' },
+	{ KEYC_KP_PERIOD|KEYC_KEYPAD, 57409, 'u' },
+	{ KEYC_KP_SLASH|KEYC_KEYPAD, 57410, 'u' },
+	{ KEYC_KP_STAR|KEYC_KEYPAD, 57411, 'u' },
+	{ KEYC_KP_MINUS|KEYC_KEYPAD, 57412, 'u' },
+	{ KEYC_KP_PLUS|KEYC_KEYPAD, 57413, 'u' },
+	{ KEYC_KP_ENTER|KEYC_KEYPAD, 57414, 'u' },
+	{ KEYC_KP_EQUAL|KEYC_KEYPAD, 57415, 'u' },
+	{ KEYC_KP_SEPARATOR|KEYC_KEYPAD, 57416, 'u' },
+	{ KEYC_KP_LEFT|KEYC_KEYPAD, 57417, 'u' },
+	{ KEYC_KP_RIGHT|KEYC_KEYPAD, 57418, 'u' },
+	{ KEYC_KP_UP|KEYC_KEYPAD, 57419, 'u' },
+	{ KEYC_KP_DOWN|KEYC_KEYPAD, 57420, 'u' },
+	{ KEYC_KP_PPAGE|KEYC_KEYPAD, 57421, 'u' },
+	{ KEYC_KP_NPAGE|KEYC_KEYPAD, 57422, 'u' },
+	{ KEYC_KP_HOME|KEYC_KEYPAD, 57423, 'u' },
+	{ KEYC_KP_END|KEYC_KEYPAD, 57424, 'u' },
+	{ KEYC_KP_IC|KEYC_KEYPAD, 57425, 'u' },
+	{ KEYC_KP_DC|KEYC_KEYPAD, 57426, 'u' },
+	{ KEYC_KP_BEGIN|KEYC_KEYPAD, 57427, '~' },
+	{ KEYC_MEDIA_PLAY, 57428, 'u' },
+	{ KEYC_MEDIA_PAUSE, 57429, 'u' },
+	{ KEYC_MEDIA_PLAYPAUSE, 57430, 'u' },
+	{ KEYC_MEDIA_REVERSE, 57431, 'u' },
+	{ KEYC_MEDIA_STOP, 57432, 'u' },
+	{ KEYC_MEDIA_FASTFORWARD, 57433, 'u' },
+	{ KEYC_MEDIA_REWIND, 57434, 'u' },
+	{ KEYC_MEDIA_NEXT, 57435, 'u' },
+	{ KEYC_MEDIA_PREVIOUS, 57436, 'u' },
+	{ KEYC_MEDIA_RECORD, 57437, 'u' },
+	{ KEYC_VOLUME_DOWN, 57438, 'u' },
+	{ KEYC_VOLUME_UP, 57439, 'u' },
+	{ KEYC_VOLUME_MUTE, 57440, 'u' },
+	{ KEYC_LEFT_SHIFT, 57441, 'u' },
+	{ KEYC_LEFT_CTRL, 57442, 'u' },
+	{ KEYC_LEFT_ALT, 57443, 'u' },
+	{ KEYC_LEFT_SUPER, 57444, 'u' },
+	{ KEYC_LEFT_HYPER, 57445, 'u' },
+	{ KEYC_LEFT_META, 57446, 'u' },
+	{ KEYC_RIGHT_SHIFT, 57447, 'u' },
+	{ KEYC_RIGHT_CTRL, 57448, 'u' },
+	{ KEYC_RIGHT_ALT, 57449, 'u' },
+	{ KEYC_RIGHT_SUPER, 57450, 'u' },
+	{ KEYC_RIGHT_HYPER, 57451, 'u' },
+	{ KEYC_RIGHT_META, 57452, 'u' },
+	{ KEYC_ISO_LEVEL3_SHIFT, 57453, 'u' },
+	{ KEYC_ISO_LEVEL5_SHIFT, 57454, 'u' }
+};
+
+void
+input_kitty_reset(struct screen *s)
+{
+	memset(&s->kitty_keys, 0, sizeof s->kitty_keys);
+}
+
+void
+input_kitty_alternate_on(struct screen *s)
+{
+	s->saved_kitty_keys = s->kitty_keys;
+	input_kitty_reset(s);
+}
+
+void
+input_kitty_alternate_off(struct screen *s)
+{
+	s->kitty_keys = s->saved_kitty_keys;
+	memset(&s->saved_kitty_keys, 0, sizeof s->saved_kitty_keys);
+}
+
+void
+input_kitty_set(struct screen *s, u_int flags, int mode)
+{
+	flags &= KITTY_KEY_SUPPORTED;
+	if (mode == 2)
+		s->kitty_keys.flags |= flags;
+	else if (mode == 3)
+		s->kitty_keys.flags &= ~flags;
+	else
+		s->kitty_keys.flags = flags;
+}
+
+void
+input_kitty_push(struct screen *s, u_int flags)
+{
+	s->kitty_keys.saved_flags = s->kitty_keys.flags;
+	s->kitty_keys.have_saved = 1;
+	s->kitty_keys.flags = flags & KITTY_KEY_SUPPORTED;
+}
+
+void
+input_kitty_pop(struct screen *s, u_int count)
+{
+	if (count == 0)
+		return;
+	if (s->kitty_keys.have_saved && count == 1)
+		s->kitty_keys.flags = s->kitty_keys.saved_flags;
+	else
+		s->kitty_keys.flags = 0;
+	s->kitty_keys.have_saved = 0;
+}
+
+static u_int
+input_kitty_modifiers(key_code key)
+{
+	u_int	modifiers = 1;
+
+	if (key & KEYC_SHIFT)
+		modifiers += 1;
+	if (key & KEYC_META)
+		modifiers += 2;
+	if (key & KEYC_CTRL)
+		modifiers += 4;
+	if (key & KEYC_SUPER)
+		modifiers += 8;
+	if (key & KEYC_HYPER)
+		modifiers += 16;
+	return (modifiers);
+}
+
+static const struct input_kitty_key *
+input_kitty_lookup(key_code key)
+{
+	key_code	lookup;
+	u_int		i;
+
+	lookup = key & (KEYC_MASK_KEY|KEYC_KEYPAD);
+	for (i = 0; i < nitems(input_kitty_keys); i++) {
+		if (input_kitty_keys[i].key == lookup)
+			return (&input_kitty_keys[i]);
+	}
+	return (NULL);
+}
+
+int
+input_key_kitty(struct screen *s, struct bufferevent *bev, key_code key)
+{
+	const struct input_kitty_key	*ikk;
+	struct utf8_data			 ud;
+	wchar_t				 wc;
+	key_code			 modifiers, onlykey;
+	u_int				 flags, number, modifier;
+	char				 tmp[64];
+	size_t				 size;
+
+	flags = s->kitty_keys.flags & KITTY_KEY_SUPPORTED;
+	if (flags == 0)
+		return (-1);
+	if ((key & KEYC_MASK_KEY) == KEYC_BTAB)
+		key = C0_HT|(key & ~KEYC_MASK_KEY)|KEYC_SHIFT;
+
+	modifiers = key & (KEYC_SHIFT|KEYC_META|KEYC_CTRL|KEYC_SUPER|KEYC_HYPER);
+	ikk = input_kitty_lookup(key);
+	if (ikk != NULL) {
+		if ((flags & KITTY_KEY_REPORT_ALL) == 0) {
+			if (ikk->key == C0_CR || ikk->key == C0_HT ||
+			    ikk->key == KEYC_BSPACE)
+				return (-1);
+			if (ikk->final != 'u' &&
+			    (modifiers & (KEYC_SUPER|KEYC_HYPER)) == 0)
+				return (-1);
+		}
+		number = ikk->number;
+		modifier = input_kitty_modifiers(key);
+		if (ikk->final == 'u') {
+			if (modifier == 1)
+				size = xsnprintf(tmp, sizeof tmp, "\033[%uu", number);
+			else
+				size = xsnprintf(tmp, sizeof tmp, "\033[%u;%uu",
+				    number, modifier);
+		} else if (ikk->final == '~') {
+			if (modifier == 1)
+				size = xsnprintf(tmp, sizeof tmp, "\033[%u~", number);
+			else
+				size = xsnprintf(tmp, sizeof tmp, "\033[%u;%u~",
+				    number, modifier);
+		} else {
+			if (modifier == 1)
+				size = xsnprintf(tmp, sizeof tmp, "\033[%c",
+				    ikk->final);
+			else
+				size = xsnprintf(tmp, sizeof tmp, "\033[1;%u%c",
+				    modifier, ikk->final);
+		}
+		goto write;
+	}
+
+	if ((flags & KITTY_KEY_REPORT_ALL) == 0 &&
+	    (modifiers & (KEYC_META|KEYC_CTRL|KEYC_SUPER|KEYC_HYPER)) == 0)
+		return (-1);
+
+	onlykey = key & KEYC_MASK_KEY;
+	if (KEYC_IS_UNICODE(key)) {
+		utf8_to_data(onlykey, &ud);
+		if (utf8_towc(&ud, &wc) != UTF8_DONE)
+			return (-1);
+		number = wc;
+	} else if (onlykey <= 0x7f)
+		number = onlykey;
+	else
+		return (-1);
+	if ((key & KEYC_SHIFT) && number >= 'A' && number <= 'Z')
+		number += 'a' - 'A';
+
+	modifier = input_kitty_modifiers(key);
+	if (modifier == 1)
+		size = xsnprintf(tmp, sizeof tmp, "\033[%uu", number);
+	else
+		size = xsnprintf(tmp, sizeof tmp, "\033[%u;%uu", number,
+		    modifier);
+
+write:
+	log_debug("%s: %.*s", __func__, (int)size, tmp);
+	bufferevent_write(bev, tmp, size);
+	return (0);
+}
--- a/input.c
+++ b/input.c
@@ -279,6 +279,10 @@ enum input_csi_type {
 	INPUT_CSI_HPA,
 	INPUT_CSI_ICH,
 	INPUT_CSI_IL,
+	INPUT_CSI_KITTY_POP,
+	INPUT_CSI_KITTY_PUSH,
+	INPUT_CSI_KITTY_QUERY,
+	INPUT_CSI_KITTY_SET,
 	INPUT_CSI_MODOFF,
 	INPUT_CSI_MODSET,
 	INPUT_CSI_QUERY,
@@ -344,7 +348,11 @@ static const struct input_table_entry input_csi_table[] = {
 	{ 'r', "",  INPUT_CSI_DECSTBM },
 	{ 's', "",  INPUT_CSI_SCP },
 	{ 't', "",  INPUT_CSI_WINOPS },
-	{ 'u', "",  INPUT_CSI_RCP }
+	{ 'u', "",  INPUT_CSI_RCP },
+	{ 'u', "<", INPUT_CSI_KITTY_POP },
+	{ 'u', "=", INPUT_CSI_KITTY_SET },
+	{ 'u', ">", INPUT_CSI_KITTY_PUSH },
+	{ 'u', "?", INPUT_CSI_KITTY_QUERY }
 };

 /* Input transition. */
@@ -1557,6 +1565,33 @@ input_csi_dispatch(struct input_ctx *ictx)
 		if (options_get_number(global_options, "extended-keys") == 2)
 			screen_write_mode_set(sctx, MODE_KEYS_EXTENDED);
 		break;
+	case INPUT_CSI_KITTY_QUERY:
+		if (options_get_number(global_options, "extended-keys") == 0)
+			break;
+		input_reply(ictx, 1, "\033[?%uu", s->kitty_keys.flags);
+		break;
+	case INPUT_CSI_KITTY_SET:
+		if (options_get_number(global_options, "extended-keys") == 0)
+			break;
+		n = input_get(ictx, 0, 0, 0);
+		m = input_get(ictx, 1, 1, 1);
+		if (n >= 0 && m >= 1 && m <= 3)
+			input_kitty_set(s, n, m);
+		break;
+	case INPUT_CSI_KITTY_PUSH:
+		if (options_get_number(global_options, "extended-keys") == 0)
+			break;
+		n = input_get(ictx, 0, 0, 0);
+		if (n >= 0)
+			input_kitty_push(s, n);
+		break;
+	case INPUT_CSI_KITTY_POP:
+		if (options_get_number(global_options, "extended-keys") == 0)
+			break;
+		n = input_get(ictx, 0, 1, 1);
+		if (n >= 0)
+			input_kitty_pop(s, n);
+		break;
 	case INPUT_CSI_WINOPS:
 		input_csi_dispatch_winops(ictx);
 		break;
@@ -3194,14 +3229,13 @@ input_osc_112(struct input_ctx *ictx, const char *p)

 /* Parse the OSC 133 D exit status. */
 static int
-input_osc_133_exit_status(const char *p, int *present)
+input_osc_133_exit_status(const char *p)
 {
 	const char	*end;
 	char		*copy;
-	char		*endptr;
+	const char	*errstr;
 	long long	 status;

-	*present = 0;
 	if (p[1] != ';' || p[2] == '\0' || strchr(p + 2, '=') == p + 2)
 		return (0);
 	end = strchr(p + 2, ';');
@@ -3215,11 +3249,9 @@ input_osc_133_exit_status(const char *p, int *present)
 		free(copy);
 		return (0);
 	}
-	*present = 1;
-	errno = 0;
-	status = (int)strtol(copy, &endptr, 10);
+	status = strtonum(copy, 0, 255, &errstr);
 	free(copy);
-	if (errno != 0 || endptr == copy || status < 0 || status > 255)
+	if (errstr != NULL)
 		return (255);
 	return (status);
 }
@@ -3264,22 +3296,6 @@ input_fire_command_event(struct window_pane *wp, const char *name)
 	events_fire(name, ep);
 }

-/* Check if an OSC 133 prompt is secondary or a continuation. */
-static int
-input_osc_133_secondary_prompt(const char *p)
-{
-	const char	*cp;
-
-	while ((cp = strstr(p, ";k=")) != NULL) {
-		cp += 3;
-		if ((*cp == 's' || *cp == 'c') &&
-		    (cp[1] == '\0' || cp[1] == ';'))
-			return (1);
-		p = cp;
-	}
-	return (0);
-}
-
 /* Handle the OSC 133 sequence. */
 static void
 input_osc_133(struct input_ctx *ictx, const char *p)
@@ -3289,7 +3305,8 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 	struct grid		*gd = s->grid;
 	u_int			 line = s->cy + gd->hsize;
 	struct grid_line	*gl = NULL;
-	int			 status, status_present;
+	const char		*cp;
+	int			 status;

 	if (line < gd->hsize + gd->sy)
 		gl = grid_get_line(gd, line);
@@ -3298,14 +3315,9 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 	case 'A':
 	case 'N':
 		if (gl != NULL) {
-			if (!(gl->flags & (GRID_LINE_START_PROMPT|
-			    GRID_LINE_SECOND_PROMPT))) {
-				gl->osc133_data.prompt_col = s->cx;
-				if (input_osc_133_secondary_prompt(p))
-					gl->flags |= GRID_LINE_SECOND_PROMPT;
-				else
-					gl->flags |= GRID_LINE_START_PROMPT;
-			}
+			memset(&gl->osc133_data, 0, sizeof gl->osc133_data);
+			gl->osc133_data.prompt_col = s->cx;
+			gl->flags |= GRID_LINE_START_PROMPT;
 		}
 		if (wp != NULL) {
 			wp->last_prompt_time = time(NULL);
@@ -3314,25 +3326,23 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 		break;
 	case 'P':
 		if (gl != NULL) {
-			if (!(gl->flags & (GRID_LINE_START_PROMPT|
-			    GRID_LINE_SECOND_PROMPT))) {
-				gl->osc133_data.prompt_col = s->cx;
-				if (input_osc_133_secondary_prompt(p))
-					gl->flags |= GRID_LINE_SECOND_PROMPT;
-				else
-					gl->flags |= GRID_LINE_START_PROMPT;
-			}
+			cp = strstr(p, ";k=s");
+			if (cp != NULL && (cp[4] == ';' || cp[4] == '\0'))
+				gl->flags |= GRID_LINE_SECOND_PROMPT;
+			else
+				gl->flags |= GRID_LINE_START_PROMPT;
+			gl->osc133_data.prompt_col = s->cx;
 		}
 		break;
 	case 'B':
 	case 'I':
-		if (gl != NULL && !(gl->flags & GRID_LINE_START_COMMAND)) {
+		if (gl != NULL) {
 			gl->flags |= GRID_LINE_START_COMMAND;
 			gl->osc133_data.cmd_col = s->cx;
 		}
 		break;
 	case 'C':
-		if (gl != NULL && !(gl->flags & GRID_LINE_START_OUTPUT)) {
+		if (gl != NULL) {
 			gl->flags |= GRID_LINE_START_OUTPUT;
 			gl->osc133_data.out_start_col = s->cx;
 		}
@@ -3345,7 +3355,7 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 		}
 		break;
 	case 'D':
-		status = input_osc_133_exit_status(p, &status_present);
+		status = input_osc_133_exit_status(p);
 		if (wp != NULL) {
 			wp->cmd_end_time = time(NULL);
 			wp->flags &= ~PANE_CMDRUNNING;
@@ -3354,8 +3364,6 @@ input_osc_133(struct input_ctx *ictx, const char *p)
 		}
 		if (gl != NULL) {
 			gl->flags |= GRID_LINE_END_OUTPUT;
-			if (status_present)
-				gl->flags |= GRID_LINE_END_OUTPUT_STATUS;
 			gl->osc133_data.out_end_col = s->cx;
 			gl->osc133_data.exit_status = status;
 		}
--- a/key-bindings.c
+++ b/key-bindings.c
@@ -52,9 +52,7 @@
 	" '#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Top,}' '<' {send -X history-top}" \
 	" '#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Bottom,}' '>' {send -X history-bottom}" \
 	" ''" \
-	" '#{?#{==:#{pane_mode},copy-mode},#{?copy_line_numbers,Line Numbers Off,Line Numbers On},}' 'L' {send -X line-numbers-toggle}" \
-	" '#{?#{==:#{pane_mode},copy-mode},#{?copy_fold_view,Fold View Off,Fold View On},}' 'O' {send -X fold-view-toggle}" \
-	" '#{?#{==:#{pane_mode},copy-mode},Edit,}' 'e' {if -F '#{selection_present}' {send -X open-selection} {send -X open-output}}" \
+	" '#{?#{==:#{pane_mode},copy-mode},#{?copy_line_numbers,Hide Line Numbers,Show Line Numbers},}' 'L' {send -X line-numbers-toggle}" \
 	" '#{?#{==:#{pane_mode},copy-mode},#{?refresh_active,Refresh Off,Refresh On},}' 'r' {send -X refresh-toggle}" \
 	" ''" \
 	" '#{?#{&&:#{buffer_size},#{!:#{pane_in_mode}}},Paste #[underscore]#{=/9/...:buffer_sample},}' 'p' {paste-buffer}" \
@@ -577,7 +575,6 @@ key_bindings_init(void)
 		"bind -Tcopy-mode C-l { send -X recentre-top-bottom }",
 		"bind -Tcopy-mode M-l { send -X cursor-centre-horizontal }",
 		"bind -Tcopy-mode C-n { send -X cursor-down }",
-		"bind -Tcopy-mode C-o { send -X select-output }",
 		"bind -Tcopy-mode C-p { send -X cursor-up }",
 		"bind -Tcopy-mode C-r { command-prompt -P -T search -ip'(search up)' -I'#{pane_search_string}' { send -X search-backward-incremental -- '%%' } }",
 		"bind -Tcopy-mode C-s { command-prompt -P -T search -ip'(search down)' -I'#{pane_search_string}' { send -X search-forward-incremental -- '%%' } }",
@@ -586,19 +583,15 @@ key_bindings_init(void)
 		"bind -Tcopy-mode Escape { send -X cancel }",
 		"bind -Tcopy-mode C-[ { send -X cancel }",
 		"bind -Tcopy-mode Space { send -X page-down }",
-		"bind -Tcopy-mode Tab { send -X toggle-output }",
-"bind -Tcopy-mode BTab { send -X toggle-output -a }",
 		"bind -Tcopy-mode , { send -X jump-reverse }",
 		"bind -Tcopy-mode \\; { send -X jump-again }",
 		"bind -Tcopy-mode F { command-prompt -P -1p'(jump backward)' { send -X jump-backward -- '%%' } }",
 		"bind -Tcopy-mode L { send -X line-numbers-toggle }",
 		"bind -Tcopy-mode N { send -X search-reverse }",
-		"bind -Tcopy-mode O { send -X fold-view-toggle }",
 		"bind -Tcopy-mode P { send -X toggle-position }",
 		"bind -Tcopy-mode R { send -X rectangle-toggle }",
 		"bind -Tcopy-mode T { command-prompt -P -1p'(jump to backward)' { send -X jump-to-backward -- '%%' } }",
 		"bind -Tcopy-mode X { send -X set-mark }",
-		"bind -Tcopy-mode e { if -F '#{selection_present}' { send -X open-selection } { send -X open-output } }",
 		"bind -Tcopy-mode f { command-prompt -P -1p'(jump forward)' { send -X jump-forward -- '%%' } }",
 		"bind -Tcopy-mode g { command-prompt -P -p'(goto line)' { send -X goto-line -- '%%' } }",
 		"bind -Tcopy-mode n { send -X search-again }",
@@ -607,7 +600,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode t { command-prompt -P -1p'(jump to forward)' { send -X jump-to-forward -- '%%' } }",
 		"bind -Tcopy-mode Home { send -X start-of-line }",
 		"bind -Tcopy-mode End { send -X end-of-line }",
-		"bind -Tcopy-mode MouseDown1Pane { select-pane; send -X toggle-output -m }",
+		"bind -Tcopy-mode MouseDown1Pane select-pane",
 		"bind -Tcopy-mode MouseDrag1Pane { select-pane; send -X begin-selection }",
 		"bind -Tcopy-mode MouseDragEnd1Pane { send -X copy-pipe-and-cancel }",
 		"bind -Tcopy-mode WheelUpPane { select-pane; send -N5 -X scroll-up }",
@@ -667,8 +660,6 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi Escape { send -X clear-selection }",
 		"bind -Tcopy-mode-vi C-[ { send -X clear-selection }",
 		"bind -Tcopy-mode-vi Space { send -X begin-selection }",
-		"bind -Tcopy-mode-vi Tab { send -X toggle-output }",
-"bind -Tcopy-mode-vi BTab { send -X toggle-output -a }",
 		"bind -Tcopy-mode-vi '$' { send -X end-of-line }",
 		"bind -Tcopy-mode-vi , { send -X jump-reverse }",
 		"bind -Tcopy-mode-vi / { command-prompt -P -T search -p'(search down)' { send -X search-forward -- '%%' } }",
@@ -696,10 +687,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi K { send -X scroll-up }",
 		"bind -Tcopy-mode-vi L { send -X bottom-line }",
 		"bind -Tcopy-mode-vi M { send -X middle-line }",
-		"bind -Tcopy-mode-vi M-e { if -F '#{selection_present}' { send -X open-selection } { send -X open-output } }",
-		"bind -Tcopy-mode-vi M-o { send -X select-output }",
 		"bind -Tcopy-mode-vi N { send -X search-reverse }",
-		"bind -Tcopy-mode-vi O { send -X fold-view-toggle }",
 		"bind -Tcopy-mode-vi P { send -X toggle-position }",
 		"bind -Tcopy-mode-vi T { command-prompt -P -1p'(jump to backward)' { send -X jump-to-backward -- '%%' } }",
 		"bind -Tcopy-mode-vi V { send -X select-line }",
@@ -727,7 +715,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi % { send -X next-matching-bracket }",
 		"bind -Tcopy-mode-vi Home { send -X start-of-line }",
 		"bind -Tcopy-mode-vi End { send -X end-of-line }",
-		"bind -Tcopy-mode-vi MouseDown1Pane { select-pane; send -X toggle-output -m }",
+		"bind -Tcopy-mode-vi MouseDown1Pane { select-pane }",
 		"bind -Tcopy-mode-vi MouseDrag1Pane { select-pane; send -X begin-selection }",
 		"bind -Tcopy-mode-vi MouseDragEnd1Pane { send -X copy-pipe-and-cancel }",
 		"bind -Tcopy-mode-vi WheelUpPane { select-pane; send -N5 -X scroll-up }",
--- a/key-string.c
+++ b/key-string.c
@@ -45,6 +45,29 @@ static const struct {
 	{ "F10",	KEYC_F10|KEYC_IMPLIED_META },
 	{ "F11",	KEYC_F11|KEYC_IMPLIED_META },
 	{ "F12",	KEYC_F12|KEYC_IMPLIED_META },
+	{ "F13",	KEYC_F13|KEYC_IMPLIED_META },
+	{ "F14",	KEYC_F14|KEYC_IMPLIED_META },
+	{ "F15",	KEYC_F15|KEYC_IMPLIED_META },
+	{ "F16",	KEYC_F16|KEYC_IMPLIED_META },
+	{ "F17",	KEYC_F17|KEYC_IMPLIED_META },
+	{ "F18",	KEYC_F18|KEYC_IMPLIED_META },
+	{ "F19",	KEYC_F19|KEYC_IMPLIED_META },
+	{ "F20",	KEYC_F20|KEYC_IMPLIED_META },
+	{ "F21",	KEYC_F21|KEYC_IMPLIED_META },
+	{ "F22",	KEYC_F22|KEYC_IMPLIED_META },
+	{ "F23",	KEYC_F23|KEYC_IMPLIED_META },
+	{ "F24",	KEYC_F24|KEYC_IMPLIED_META },
+	{ "F25",	KEYC_F25|KEYC_IMPLIED_META },
+	{ "F26",	KEYC_F26|KEYC_IMPLIED_META },
+	{ "F27",	KEYC_F27|KEYC_IMPLIED_META },
+	{ "F28",	KEYC_F28|KEYC_IMPLIED_META },
+	{ "F29",	KEYC_F29|KEYC_IMPLIED_META },
+	{ "F30",	KEYC_F30|KEYC_IMPLIED_META },
+	{ "F31",	KEYC_F31|KEYC_IMPLIED_META },
+	{ "F32",	KEYC_F32|KEYC_IMPLIED_META },
+	{ "F33",	KEYC_F33|KEYC_IMPLIED_META },
+	{ "F34",	KEYC_F34|KEYC_IMPLIED_META },
+	{ "F35",	KEYC_F35|KEYC_IMPLIED_META },
 	{ "IC",		KEYC_IC|KEYC_IMPLIED_META },
 	{ "Insert",	KEYC_IC|KEYC_IMPLIED_META },
 	{ "DC",		KEYC_DC|KEYC_IMPLIED_META },
@@ -122,6 +145,54 @@ static const struct {
 	{ "KPEnter",	KEYC_KP_ENTER|KEYC_KEYPAD },
 	{ "KP0",	KEYC_KP_ZERO|KEYC_KEYPAD },
 	{ "KP.",	KEYC_KP_PERIOD|KEYC_KEYPAD },
+	{ "KP=",	KEYC_KP_EQUAL|KEYC_KEYPAD },
+	{ "KP,",	KEYC_KP_SEPARATOR|KEYC_KEYPAD },
+	{ "KPLeft",	KEYC_KP_LEFT|KEYC_KEYPAD },
+	{ "KPRight",	KEYC_KP_RIGHT|KEYC_KEYPAD },
+	{ "KPUp",	KEYC_KP_UP|KEYC_KEYPAD },
+	{ "KPDown",	KEYC_KP_DOWN|KEYC_KEYPAD },
+	{ "KPPageUp",	KEYC_KP_PPAGE|KEYC_KEYPAD },
+	{ "KPPageDown",	KEYC_KP_NPAGE|KEYC_KEYPAD },
+	{ "KPHome",	KEYC_KP_HOME|KEYC_KEYPAD },
+	{ "KPEnd",	KEYC_KP_END|KEYC_KEYPAD },
+	{ "KPInsert",	KEYC_KP_IC|KEYC_KEYPAD },
+	{ "KPDelete",	KEYC_KP_DC|KEYC_KEYPAD },
+	{ "KPBegin",	KEYC_KP_BEGIN|KEYC_KEYPAD },
+
+	/* Other function keys. */
+	{ "CapsLock",	KEYC_CAPSLOCK },
+	{ "ScrollLock",	KEYC_SCROLLLOCK },
+	{ "NumLock",	KEYC_NUMLOCK },
+	{ "PrintScreen", KEYC_PRINTSCREEN },
+	{ "Pause",	KEYC_PAUSE },
+	{ "Menu",	KEYC_MENU },
+	{ "MediaPlay",	KEYC_MEDIA_PLAY },
+	{ "MediaPause", KEYC_MEDIA_PAUSE },
+	{ "MediaPlayPause", KEYC_MEDIA_PLAYPAUSE },
+	{ "MediaReverse", KEYC_MEDIA_REVERSE },
+	{ "MediaStop",	KEYC_MEDIA_STOP },
+	{ "MediaFastForward", KEYC_MEDIA_FASTFORWARD },
+	{ "MediaRewind", KEYC_MEDIA_REWIND },
+	{ "MediaNext",	KEYC_MEDIA_NEXT },
+	{ "MediaPrevious", KEYC_MEDIA_PREVIOUS },
+	{ "MediaRecord", KEYC_MEDIA_RECORD },
+	{ "VolumeDown", KEYC_VOLUME_DOWN },
+	{ "VolumeUp",	KEYC_VOLUME_UP },
+	{ "VolumeMute", KEYC_VOLUME_MUTE },
+	{ "LeftShift",	KEYC_LEFT_SHIFT },
+	{ "LeftControl", KEYC_LEFT_CTRL },
+	{ "LeftAlt",	KEYC_LEFT_ALT },
+	{ "LeftSuper",	KEYC_LEFT_SUPER },
+	{ "LeftHyper",	KEYC_LEFT_HYPER },
+	{ "LeftMeta",	KEYC_LEFT_META },
+	{ "RightShift", KEYC_RIGHT_SHIFT },
+	{ "RightControl", KEYC_RIGHT_CTRL },
+	{ "RightAlt",	KEYC_RIGHT_ALT },
+	{ "RightSuper", KEYC_RIGHT_SUPER },
+	{ "RightHyper", KEYC_RIGHT_HYPER },
+	{ "RightMeta",	KEYC_RIGHT_META },
+	{ "ISOLevel3Shift", KEYC_ISO_LEVEL3_SHIFT },
+	{ "ISOLevel5Shift", KEYC_ISO_LEVEL5_SHIFT },

 	/* Mouse keys. */
 	KEYC_MOUSE_STRING(MOUSEDOWN1, MouseDown1),
@@ -226,9 +297,14 @@ key_string_get_modifiers(const char **string)
 			modifiers |= KEYC_META;
 			break;
 		case 'S':
-		case 's':
 			modifiers |= KEYC_SHIFT;
 			break;
+		case 's':
+			modifiers |= KEYC_SUPER;
+			break;
+		case 'H':
+			modifiers |= KEYC_HYPER;
+			break;
 		default:
 			*string = NULL;
 			return (0);
@@ -349,6 +425,10 @@ key_string_lookup_key(key_code key, int with_flags)
 		strlcat(out, "M-", sizeof out);
 	if (key & KEYC_SHIFT)
 		strlcat(out, "S-", sizeof out);
+	if (key & KEYC_SUPER)
+		strlcat(out, "s-", sizeof out);
+	if (key & KEYC_HYPER)
+		strlcat(out, "H-", sizeof out);
 	key &= KEYC_MASK_KEY;

 	/* Handle no key. */
--- a/options-table.c
+++ b/options-table.c
@@ -104,7 +104,7 @@ static const char *options_table_extended_keys_list[] = {
 	"off", "on", "always", NULL
 };
 static const char *options_table_extended_keys_format_list[] = {
-	"csi-u", "xterm", NULL
+	"csi-u", "xterm", "kitty", NULL
 };
 static const char *options_table_allow_passthrough_list[] = {
 	"off", "on", "all", NULL
@@ -115,6 +115,7 @@ static const char *options_table_theme_list[] = {
 static const char *options_table_copy_mode_line_numbers_list[] = {
 	"off", "default", "absolute", "relative", "hybrid", NULL
 };
+
 /* Status line format. */
 #define OPTIONS_TABLE_STATUS_FORMAT1 \
 	"#[align=left range=left #{E:status-left-style}]" \
@@ -1384,13 +1385,6 @@ const struct options_table_entry options_table[] = {
 	  .text = "Style of search matches in copy mode."
 	},

-	{ .name = "copy-mode-exit-status-format",
-	  .type = OPTIONS_TABLE_STRING,
-	  .scope = OPTIONS_TABLE_WINDOW|OPTIONS_TABLE_PANE,
-	  .default_str = "#{?exit_status,#[fg=themered]!, }",
-	  .text = "Format of OSC 133 exit status indicator in copy mode."
-	},
-
 	{ .name = "copy-mode-current-match-style",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_WINDOW,
--- a/options.c
+++ b/options.c
@@ -1400,6 +1400,12 @@ options_push_changes(const char *name)
 		TAILQ_FOREACH(loop, &clients, entry)
 			server_client_set_key_table(loop, NULL);
 	}
+	if (strcmp(name, "extended-keys") == 0) {
+		TAILQ_FOREACH(loop, &clients, entry) {
+			if (loop->tty.flags & TTY_STARTED)
+				tty_update_features(&loop->tty);
+		}
+	}
 	if (strcmp(name, "user-keys") == 0) {
 		TAILQ_FOREACH(loop, &clients, entry) {
 			if (loop->tty.flags & TTY_OPENED)
--- a/regress/collapse-output.sh
+++ b/regress/collapse-output.sh
@@ -1,81 +0,0 @@
-#!/bin/sh
-
-PATH=/bin:/usr/bin
-TERM=screen
-
-[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
-
-$TMUX kill-server 2>/dev/null
-$TMUX new-session -d -x80 -y20 "sh -c 'printf \"\\033]133;A\\007p\\$ \\033]133;B\\007echo hi\\n\\033]133;C\\007hello\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007\"; exec sleep 100'" || exit 1
-sleep 1
-
-$TMUX copy-mode -c || exit 1
-$TMUX send-keys -X search-backward hello || exit 1
-hidden=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$hidden" != hello ] || exit 1
-$TMUX send-keys -X search-backward separator || exit 1
-hidden=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$hidden" != separator ] || exit 1
-
-$TMUX send-keys BTab || exit 1
-$TMUX send-keys -X search-backward hello || exit 1
-shown=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$shown" = hello ] || exit 1
-$TMUX send-keys -X select-line || exit 1
-$TMUX send-keys -X copy-selection || exit 1
-selected=$($TMUX show-buffer)
-[ "$selected" = hello ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX kill-server
-$TMUX new-session -d -x80 -y20 "sh -c 'printf \"first\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007\"; exec sleep 100'" || exit 1
-sleep 1
-
-$TMUX copy-mode -c || exit 1
-$TMUX send-keys -X search-backward separator || exit 1
-hidden=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$hidden" != separator ] || exit 1
-$TMUX send-keys BTab || exit 1
-$TMUX send-keys -X search-backward separator || exit 1
-shown=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$shown" = separator ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX kill-server
-$TMUX new-session -d -x80 -y20 "sh -c 'printf \"\\033]133;A\\007P> \\033]133;B\\007for i in 1 2 3; do\\n\\033]133;A;k=s\\007> \\033]133;B\\007echo \\$i\\n\\033]133;P;k=s\\007> \\033]133;B\\007done\\033]133;C\\007\\nRESULT\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007P> \\033]133;B\\007\"; exec sleep 100'" || exit 1
-sleep 1
-
-$TMUX copy-mode -c || exit 1
-$TMUX send-keys -X search-backward RESULT || exit 1
-hidden=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$hidden" != RESULT ] || exit 1
-$TMUX send-keys -X search-backward 'echo $i' || exit 1
-shown=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$shown" = 'echo $i' ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX copy-mode -U || exit 1
-$TMUX send-keys -X search-backward RESULT || exit 1
-$TMUX send-keys Tab || exit 1
-cursor=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$cursor" = done ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX kill-server
-$TMUX new-session -d -x80 -y20 "sh -c 'printf \"\\033]133;A\\007P0> \\033]133;B\\007\\r\\n\\033]133;D;0\\007empty-separator\\n\\033]133;A\\007P1> \\033]133;B\\007\"; exec sleep 100'" || exit 1
-sleep 1
-
-$TMUX copy-mode -c || exit 1
-collapsed=$($TMUX capture-pane -p)
-case "$collapsed" in
-*"+ P0>"*) ;;
-*) exit 1 ;;
-esac
-$TMUX send-keys -X search-backward empty-separator || exit 1
-hidden=$($TMUX display-message -p '#{copy_cursor_line}')
-[ "$hidden" != empty-separator ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX kill-server 2>/dev/null
-exit 0
--- a/regress/copy-mode-exit-status.sh
+++ b/regress/copy-mode-exit-status.sh
@@ -1,102 +0,0 @@
-#!/bin/sh
-
-# Check OSC 133 exit status indicators in copy mode using a real client.
-
-PATH=/bin:/usr/bin
-TERM=screen
-LC_ALL=C.UTF-8
-export TERM LC_ALL
-
-[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
-TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
-
-fail() {
-	echo "$*" >&2
-	exit 1
-}
-
-capture() {
-	$TMUX capture-pane -pS0 -E- >$TMP || exit 1
-}
-
-check_grep() {
-	grep -Fq "$1" $TMP || fail "missing pattern: $1"
-}
-
-check_no_grep() {
-	grep -Fq "$1" $TMP && fail "unexpected pattern: $1"
-}
-
-$TMUX kill-server 2>/dev/null
-$TMUX2 kill-server 2>/dev/null
-
-TMP=$(mktemp)
-trap "rm -f $TMP; $TMUX kill-server 2>/dev/null; $TMUX2 kill-server 2>/dev/null" 0 1 15
-
-$TMUX2 new-session -d -x80 -y10 \
-	"printf '\033]133;A\007p\$ \033]133;B\007one\n\033]133;C\007out1\n\033]133;D;0\007\033]133;A\007p\$ \033]133;B\007two\n\033]133;C\007out2\n\033]133;D;123\007\033]133;A\007p\$ \033]133;B\007silent\n\033]133;C\007\033]133;D;7\007\033]133;A\007p\$ \033]133;B\007three\n\033]133;C\007out3\n\033]133;D\007\033]133;A\007p\$ \033]133;B\007'; exec sleep 100" || \
-	exit 1
-$TMUX2 set -g status off || exit 1
-$TMUX2 set -g copy-mode-position-format '#[align=left]POS' || exit 1
-$TMUX2 list-keys -Tcopy-mode O | grep -Fq 'fold-view-toggle' || exit 1
-$TMUX2 list-keys -Tcopy-mode-vi O | grep -Fq 'fold-view-toggle' || exit 1
-
-$TMUX new-session -d -x80 -y10 || exit 1
-$TMUX set -g status off || exit 1
-$TMUX send -l "$TMUX2 attach" || exit 1
-$TMUX send Enter || exit 1
-sleep 1
-
-$TMUX2 copy-mode -U || exit 1
-$TMUX2 send -X history-top || exit 1
-sleep 1
-capture
-check_grep "!- p\$ two"
-check_grep "!  p\$ silent"
-check_no_grep "!+ p\$ silent"
-check_grep "POS"
-
-# Rebuilding with collapsed output must not expand copy-mode formats before
-# the viewport has been restored for the shorter backing grid.
-$TMUX2 send -X collapse-output -a || exit 1
-sleep 1
-capture
-check_grep "!+ p\$ two"
-check_grep "!  p\$ silent"
-check_no_grep "!+ p\$ silent"
-$TMUX2 send -X line-numbers-on || exit 1
-sleep 1
-capture
-check_grep "  3 !+ p\$ two"
-$TMUX2 send -X fold-view-toggle || exit 1
-[ "$($TMUX2 display -p '#{copy_fold_view}')" = 0 ] || exit 1
-sleep 1
-capture
-check_grep "out2"
-check_no_grep "!+ p\$ two"
-check_grep "  3 p\$ two"
-$TMUX2 send -X fold-view-toggle || exit 1
-[ "$($TMUX2 display -p '#{copy_fold_view}')" = 1 ] || exit 1
-sleep 1
-capture
-check_grep "  3 !- p\$ two"
-
-# A format wider than the standard three-column gutter is not truncated.
-$TMUX2 send -X cancel || exit 1
-$TMUX2 set -g copy-mode-exit-status-format \
-	'#[align=right]#{?exit_status,!#{exit_status}, }' || exit 1
-$TMUX2 copy-mode -c || exit 1
-$TMUX2 send -X history-top || exit 1
-sleep 1
-capture
-check_grep "!123+ p\$ two"
-
-$TMUX2 send -X select-line || exit 1
-$TMUX2 send -X copy-selection || exit 1
-selection=$($TMUX2 show-buffer)
-case $selection in
-*RC=*) fail "exit status was copied" ;;
-esac
-
-exit 0
--- a/regress/input-modes.sh
+++ b/regress/input-modes.sh
@@ -5,12 +5,9 @@
 start_pane alternate 10 3 'MAIN\033[?1049hALT\033[?1049lZ\n'
 check_capture alternate 'MAINZ'

-start_pane osc133 20 12 'xx\033]133;A\007p>\033]133;B\007cmd\nxy\033]133;P;k=s\007more\nxz\033]133;A;k=s\007more\nxw\033]133;P;k=c\007more\nxv\033]133;A;k=c\007more\nzz\033]133;C\007out\033]133;D;7\007\nq\033]133;C\007bad\033]133;D;-1\007\nqq\033]133;C\007big\033]133;D;300\007\nzzz\033]133;C\007ok\033]133;D\007\n'
+start_pane osc133 20 8 'xx\033]133;A\007p>\033]133;B\007cmd\nxy\033]133;P;k=s\007more\nzz\033]133;C\007out\033]133;D;7\007\nq\033]133;C\007bad\033]133;D;-1\007\nqq\033]133;C\007big\033]133;D;300\007\nzzz\033]133;C\007ok\033]133;D\007\n'
 check_capture osc133 'xxp>cmd
 xymore
-xzmore
-xwmore
-xvmore
 zzout
 qbad
 qqbig
@@ -18,13 +15,10 @@ zzzok'
 check_raw_matches osc133 \
 	'L 0 \(0\) flags=START_PROMPT,START_COMMAND\[[0-9a-f]+\].* osc133=2,4,0,0,0' \
 	'L 1 \(1\) flags=SECOND_PROMPT\[[0-9a-f]+\].* osc133=2,0,0,0,0' \
-	'L 2 \(2\) flags=SECOND_PROMPT\[[0-9a-f]+\].* osc133=2,0,0,0,0' \
-	'L 3 \(3\) flags=SECOND_PROMPT\[[0-9a-f]+\].* osc133=2,0,0,0,0' \
-	'L 4 \(4\) flags=SECOND_PROMPT\[[0-9a-f]+\].* osc133=2,0,0,0,0' \
-	'L 5 \(5\) flags=START_OUTPUT,END_OUTPUT,END_OUTPUT_STATUS\[[0-9a-f]+\].* osc133=0,0,2,5,7' \
-	'L 6 \(6\) flags=START_OUTPUT,END_OUTPUT,END_OUTPUT_STATUS\[[0-9a-f]+\].* osc133=0,0,1,4,255' \
-	'L 7 \(7\) flags=START_OUTPUT,END_OUTPUT,END_OUTPUT_STATUS\[[0-9a-f]+\].* osc133=0,0,2,5,255' \
-	'L 8 \(8\) flags=START_OUTPUT,END_OUTPUT\[[0-9a-f]+\].* osc133=0,0,3,5,0'
+	'L 2 \(2\) flags=START_OUTPUT,END_OUTPUT\[[0-9a-f]+\].* osc133=0,0,2,5,7' \
+	'L 3 \(3\) flags=START_OUTPUT,END_OUTPUT\[[0-9a-f]+\].* osc133=0,0,1,4,255' \
+	'L 4 \(4\) flags=START_OUTPUT,END_OUTPUT\[[0-9a-f]+\].* osc133=0,0,2,5,255' \
+	'L 5 \(5\) flags=START_OUTPUT,END_OUTPUT\[[0-9a-f]+\].* osc133=0,0,3,5,0'

 $TMUX kill-server 2>/dev/null
 exit $exit_status
--- a/regress/kitty-keys-clients.sh
+++ b/regress/kitty-keys-clients.sh
@@ -0,0 +1,146 @@
+#!/bin/sh
+
+# Test per-client keyboard protocol detection and pane-side encoding.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+KCONF=$(mktemp)
+LCONF=$(mktemp)
+OUT=$(mktemp)
+TMP=$(mktemp)
+SOCKETS="testKmc$$ testKka$$ testKua$$ testKrt$$ testKru$$ testKlq$$ testKlu$$"
+
+printf '%s\n' 'set -g extended-keys on' >"$KCONF"
+printf '%s\n' 'set -g extended-keys off' >"$LCONF"
+
+cleanup()
+{
+	rm -f "$KCONF" "$LCONF" "$OUT" "$TMP"
+	for socket in $SOCKETS; do
+		$TEST_TMUX -L"$socket" kill-server 2>/dev/null
+	done
+}
+trap cleanup 0 1 15
+
+wait_for_mode()
+{
+	tmux=$1
+	wanted=$2
+	i=0
+	while [ "$($tmux display-message -pt: '#{pane_key_mode}')" != "$wanted" ] &&
+	    [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$($tmux display-message -pt: '#{pane_key_mode}')" = "$wanted" ]
+}
+
+wait_for_output()
+{
+	i=0
+	while [ ! -s "$1" ] && [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ -s "$1" ]
+}
+
+client_mode()
+{
+	tmux=$1
+	session=$2
+
+	if [ -z "$session" ]; then
+		$tmux list-clients -F '#{client_key_mode}'
+	else
+		$tmux list-clients -F '#{client_session}:#{client_key_mode}' |
+		    sed -n "s/^$session://p"
+	fi
+}
+
+wait_for_client_mode()
+{
+	tmux=$1
+	session=$2
+	wanted=$3
+	i=0
+	while [ "$(client_mode "$tmux" "$session")" != "$wanted" ] &&
+	    [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$(client_mode "$tmux" "$session")" = "$wanted" ]
+}
+
+# Each client must be negotiated independently. A tmux with extended-keys off
+# stands in for a terminal without Kitty keys, since it does not answer the
+# query.
+M="$TEST_TMUX -LtestKmc$$ -f$KCONF"
+KA="$TEST_TMUX -LtestKka$$ -f$KCONF"
+UA="$TEST_TMUX -LtestKua$$ -f$LCONF"
+$M new-session -d -x80 -y24 -s kitty || exit 1
+$M new-session -d -x80 -y24 -s csiu || exit 1
+$KA new-session -d -x80 -y24 "$M attach-session -t kitty" || exit 1
+$UA new-session -d -x80 -y24 "$M attach-session -t csiu" || exit 1
+wait_for_mode "$KA" 'Kitty 1' || exit 1
+
+# Each client must report the protocol its own terminal negotiated.
+wait_for_client_mode "$M" kitty 'Kitty 1' || exit 1
+wait_for_client_mode "$M" csiu 'Ext' || exit 1
+
+uc=$($M list-clients -F '#{client_name} #{client_session}' |
+    awk '$2 == "csiu" { print $1 }')
+[ -n "$uc" ] || exit 1
+$M command-prompt -t"$uc" -k 'display-message -pl "%%"' >"$TMP" &
+pid=$!
+sleep 0.2
+$UA send-keys Escape '[97;5u'
+wait "$pid"
+[ "$(tr -d '[:space:]' <"$TMP")" = 'C-a' ] || exit 1
+
+# A Kitty-capable terminal must still be reported when it is not in use.
+$M set-option -g extended-keys off
+wait_for_client_mode "$M" kitty 'VT10x (Kitty)' || exit 1
+wait_for_client_mode "$M" csiu 'VT10x' || exit 1
+$M set-option -g extended-keys on
+wait_for_client_mode "$M" kitty 'Kitty 1' || exit 1
+
+$KA kill-server 2>/dev/null
+$UA kill-server 2>/dev/null
+$M kill-server 2>/dev/null
+
+# Standard extended input must be translated for a Kitty-requesting pane.
+: >"$OUT"
+R="$TEST_TMUX -LtestKrt$$ -f$KCONF"
+RU="$TEST_TMUX -LtestKru$$ -f$LCONF"
+$R new-session -d -x80 -y24 \
+    "stty raw -echo; printf '\033[>1u'; dd bs=1 count=7 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5" || exit 1
+$RU new-session -d -x80 -y24 "$R attach-session" || exit 1
+wait_for_client_mode "$R" '' 'Ext' || exit 1
+$RU send-keys C-a
+wait_for_output "$OUT" || exit 1
+[ "$(tr -d ' \n' <"$OUT")" = '1b5b39373b3575' ] || exit 1
+$RU kill-server 2>/dev/null
+$R kill-server 2>/dev/null
+
+# An application is told the Kitty flags it asked for even when a client that
+# only supports VT10x is attached, and keys from that client are encoded as it
+# asked.
+: >"$OUT"
+: >"$TMP"
+printf '%s\n' "set -as terminal-overrides ',*:Eneks@:Dseks@'" >>"$KCONF"
+LQ="$TEST_TMUX -LtestKlq$$ -f$KCONF"
+LU="$TEST_TMUX -LtestKlu$$ -f$LCONF"
+$LQ new-session -d -x80 -y24 \
+    "stty raw -echo; sleep 2; printf '\033[>1u\033[?u'; dd bs=1 count=5 2>/dev/null | od -An -v -t x1 >'$OUT'; dd bs=1 count=7 2>/dev/null | od -An -v -t x1 >'$TMP'; sleep 5" || exit 1
+$LU new-session -d -x80 -y24 "$LQ attach-session" || exit 1
+wait_for_output "$OUT" || exit 1
+[ "$(tr -d ' \n' <"$OUT")" = '1b5b3f3175' ] || exit 1
+wait_for_client_mode "$LQ" '' 'VT10x' || exit 1
+$LU send-keys C-a
+wait_for_output "$TMP" || exit 1
+[ "$(tr -d ' \n' <"$TMP")" = '1b5b39373b3575' ] || exit 1
+
+exit 0
--- a/regress/kitty-keys-input.sh
+++ b/regress/kitty-keys-input.sh
@@ -0,0 +1,116 @@
+#!/bin/sh
+
+# Test client-side Kitty keyboard protocol support: an outer tmux acts as a
+# Kitty-capable terminal for the inner tmux which is the one under test. The
+# inner tmux queries the outer one, the outer one replies, and the inner one
+# then parses the key sequences sent to it.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+CONF=$(mktemp)
+TMP=$(mktemp)
+
+printf '%s\n' 'set -g extended-keys on' >"$CONF"
+
+TMUX="$TEST_TMUX -LtestKIA$$ -f$CONF"
+TMUX2="$TEST_TMUX -LtestKIB$$ -f$CONF"
+
+trap 'rm -f "$CONF" "$TMP"; $TMUX kill-server 2>/dev/null; \
+    $TMUX2 kill-server 2>/dev/null' 0 1 15
+
+$TMUX2 new-session -d -x80 -y24 || exit 1
+$TMUX new-session -d -x80 -y24 "$TMUX2 attach" || exit 1
+
+exit_status=0
+
+wait_for_mode()
+{
+	i=0
+	while [ "$($TMUX display-message -pt: '#{pane_key_mode}')" != "$1" ] &&
+	    [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$($TMUX display-message -pt: '#{pane_key_mode}')" = "$1" ]
+}
+
+assert_key()
+{
+	keys=$1
+	expected=$2
+
+	$TMUX2 command-prompt -k 'display-message -pl "%%"' >"$TMP" &
+	sleep 0.15
+	# Send raw bytes so the outer tmux does not encode them itself.
+	raw=$(printf '%s' "$keys" | sed -e 's/Escape /\\033/g' -e 's/ //g')
+	$TMUX send-keys -H $(printf "$raw" | od -An -v -t x1)
+	wait
+
+	actual=$(tr -d '[:space:]' <"$TMP")
+	if [ "$actual" = "$expected" ]; then
+		[ -n "$VERBOSE" ] && echo "[PASS] $keys -> $actual"
+	else
+		echo "[FAIL] $keys -> $expected (got '$actual')"
+		exit_status=1
+	fi
+}
+
+# The inner tmux must detect the outer one and push its flags.
+if ! wait_for_mode 'Kitty 1'; then
+	echo "[FAIL] inner tmux did not enable the Kitty protocol"
+	exit 1
+fi
+
+# Modifiers, including the Kitty-only Super and Hyper.
+assert_key 'Escape [97;2u' 'S-a'
+assert_key 'Escape [97;3u' 'M-a'
+assert_key 'Escape [97;5u' 'C-a'
+assert_key 'Escape [97;6u' 'C-S-a'
+assert_key 'Escape [97;7u' 'C-M-a'
+assert_key 'Escape [97;9u' 's-a'
+assert_key 'Escape [97;17u' 'H-a'
+assert_key 'Escape [65;2u' 'S-A'
+
+# Keys with a dedicated tmux key code.
+assert_key 'Escape [9;5u' 'C-Tab'
+assert_key 'Escape [9;2u' 'BTab'
+assert_key 'Escape [13;5u' 'C-Enter'
+assert_key 'Escape [27u' 'Escape'
+assert_key 'Escape [32;5u' 'C-Space'
+assert_key 'Escape [127;5u' 'C-BSpace'
+
+# Keys with a CSI final byte other than u.
+assert_key 'Escape [1;5A' 'C-Up'
+assert_key 'Escape [1;3D' 'M-Left'
+assert_key 'Escape [1;5H' 'C-Home'
+assert_key 'Escape [1;5P' 'C-F1'
+
+# Functional and non-ASCII keys.
+assert_key 'Escape [57399;5u' 'C-KP0'
+assert_key 'Escape [233;5u' 'C-é'
+
+# The alternate key and associated text fields are not requested but must be
+# ignored if a terminal sends them anyway.
+assert_key 'Escape [97:65;2u' 'S-a'
+assert_key 'Escape [97:65:97;5u' 'C-a'
+assert_key 'Escape [97;5;97u' 'C-a'
+
+# A repeat event is a key press, a release event is dropped. The C-b that
+# follows shows that the sequence was consumed and not passed through.
+assert_key 'Escape [97;5:1u' 'C-a'
+assert_key 'Escape [97;5:2u' 'C-a'
+assert_key 'Escape [97;5:3u Escape [98;5u' 'C-b'
+
+# The Meta modifier bit is not representable and is dropped.
+assert_key 'Escape [97;33u Escape [98;5u' 'C-b'
+
+# Lock modifiers are ignored rather than dropping the key.
+assert_key 'Escape [97;65u' 'a'
+assert_key 'Escape [97;129u' 'a'
+
+$TMUX kill-server 2>/dev/null
+$TMUX2 kill-server 2>/dev/null
+
+exit $exit_status
--- a/regress/kitty-keys-terminal.sh
+++ b/regress/kitty-keys-terminal.sh
@@ -0,0 +1,85 @@
+#!/bin/sh
+
+# Test the Kitty keyboard protocol against a real terminal rather than against
+# another copy of tmux. This drives kitty through its remote control interface
+# so that kitty itself encodes the key presses.
+#
+# This has to be run by hand from this directory. The Makefile runs tests with
+# env -i, which removes DISPLAY and HOME, so kitty cannot start and this exits
+# immediately without testing anything. It is also skipped unless kitty is
+# installed and is new enough to have send-key.
+
+PATH=/bin:/usr/bin
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+command -v kitty >/dev/null 2>&1 || exit 0
+[ -n "$DISPLAY" ] || [ -n "$WAYLAND_DISPLAY" ] || exit 0
+kitty @ --help 2>/dev/null | grep -q 'send-key' || exit 0
+
+DIR=$(mktemp -d)
+CONF=$DIR/conf
+SOCKET=$DIR/kitty
+OUT=$DIR/out
+TMUX="$TEST_TMUX -LtestKrt$$ -f$CONF"
+
+printf '%s\n' 'set -g extended-keys on' \
+    'set -g extended-keys-format kitty' >"$CONF"
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$DIR"
+}
+trap cleanup 0 1 15
+
+kitty -o allow_remote_control=yes --listen-on "unix:$SOCKET" \
+    -o confirm_os_window_close=0 -e \
+    $TMUX new-session -s r "sleep 120" >"$DIR/err" 2>&1 &
+
+# The terminfo entry for kitty may be missing, so treat a server which never
+# appears as a reason to skip rather than as a failure.
+i=0
+while ! $TMUX has-session -t r 2>/dev/null && [ "$i" -lt 150 ]; do
+	sleep 0.1
+	i=$((i + 1))
+done
+$TMUX has-session -t r 2>/dev/null || exit 0
+
+# The client must negotiate the protocol with the real terminal.
+i=0
+while [ "$($TMUX list-clients -F '#{client_key_mode}')" != 'Kitty 1' ] &&
+    [ "$i" -lt 100 ]; do
+	sleep 0.1
+	i=$((i + 1))
+done
+[ "$($TMUX list-clients -F '#{client_key_mode}')" = 'Kitty 1' ] || exit 1
+
+# kitty encodes the key, tmux parses it and encodes it again for the pane.
+try_key()
+{
+	key=$1
+	expected=$2
+
+	: >"$OUT"
+	$TMUX respawn-pane -k -t r: \
+	    "stty raw -echo; printf '\033[>1u'; dd bs=1 count=7 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 20" || return 1
+	sleep 1
+	kitty @ --to "unix:$SOCKET" send-key "$key" 2>/dev/null || return 1
+	i=0
+	while [ ! -s "$OUT" ] && [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$(tr -d ' \n' <"$OUT")" = "$expected" ]
+}
+
+try_key ctrl+a '1b5b39373b3575' || exit 1
+try_key alt+a '1b5b39373b3375' || exit 1
+try_key ctrl+shift+a '1b5b39373b3675' || exit 1
+
+# Super cannot be represented by the standard extended keys at all, so this
+# only succeeds if the whole chain used the Kitty protocol.
+try_key super+a '1b5b39373b3975' || exit 1
+
+exit 0
--- a/regress/kitty-keys.sh
+++ b/regress/kitty-keys.sh
@@ -0,0 +1,108 @@
+#!/bin/sh
+
+# Test pane-side Kitty keyboard protocol state and key encoding. This uses
+# synthetic protocol sequences and does not require a particular terminal.
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+CONF=$(mktemp)
+OUT=$(mktemp)
+TMUX="$TEST_TMUX -LtestK$$ -f$CONF"
+
+trap 'rm -f "$CONF" "$OUT"; $TMUX kill-server 2>/dev/null' 0 1 15
+
+printf '%s\n' 'set -g extended-keys on' >"$CONF"
+
+wait_for_output()
+{
+	i=0
+	while [ ! -s "$OUT" ] && [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ -s "$OUT" ]
+}
+
+wait_for_mode()
+{
+	wanted=$1
+	i=0
+	while [ "$($TMUX display-message -pt: '#{pane_key_mode}')" != "$wanted" ] &&
+	    [ "$i" -lt 50 ]; do
+		sleep 0.1
+		i=$((i + 1))
+	done
+	[ "$($TMUX display-message -pt: '#{pane_key_mode}')" = "$wanted" ]
+}
+
+check_output()
+{
+	expected=$1
+	actual=$(tr -d ' \n' <"$OUT")
+	if [ "$actual" != "$expected" ]; then
+		echo "expected $expected, got $actual"
+		exit 1
+	fi
+}
+
+$TMUX new-session -d -x80 -y24 \
+    "stty raw -echo; printf '\033[>1u'; dd bs=1 count=7 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5" || exit 1
+wait_for_mode 'Kitty 1'
+$TMUX send-keys -t: C-S-a
+wait_for_output
+check_output 1b5b39373b3675
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>1u'; dd bs=1 count=7 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_mode 'Kitty 1'
+$TMUX send-keys -t: s-a
+wait_for_output
+check_output 1b5b39373b3975
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>8u'; dd bs=1 count=5 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_mode 'Kitty 8'
+$TMUX send-keys -t: a
+wait_for_output
+check_output 1b5b393775
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>1u\033[?u'; dd bs=1 count=5 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_output
+check_output 1b5b3f3175
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>4;2m\033[?u'; dd bs=1 count=5 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_output
+check_output 1b5b3f3075
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>1u\033[>8u\033[<u\033[?u\033[>8u\033[<2u\033[?u'; dd bs=1 count=10 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_output
+check_output 1b5b3f31751b5b3f3075
+
+: >"$OUT"
+# "always" forces modifyOtherKeys mode 1, not Kitty keys.
+$TMUX set-option -g extended-keys always
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>0u\033[?u'; dd bs=1 count=5 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_output
+check_output 1b5b3f3075
+wait_for_mode 'Ext 1'
+$TMUX set-option -g extended-keys on
+
+: >"$OUT"
+$TMUX respawn-pane -k -t: \
+    "stty raw -echo; printf '\033[>1u\033[?u\033[?1049h\033[?u\033[>8u\033[?u\033[?1049l\033[?u'; dd bs=1 count=20 2>/dev/null | od -An -v -t x1 >'$OUT'; sleep 5"
+wait_for_output
+check_output 1b5b3f31751b5b3f30751b5b3f38751b5b3f3175
+
+$TMUX kill-server 2>/dev/null
+exit 0
--- a/regress/output-commands.sh
+++ b/regress/output-commands.sh
@@ -1,131 +0,0 @@
-#!/bin/sh
-
-PATH=/bin:/usr/bin
-TERM=screen
-
-[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
-TMUX="$TEST_TMUX -L${TEST_SOCKET:-testO$$} -f/dev/null"
-OUT=/tmp/tmux-output-commands-$$
-EXPECTED=$(printf 'one\ntwo')
-
-cleanup()
-{
-	$TMUX kill-server 2>/dev/null
-	rm -f "$OUT"
-}
-trap cleanup EXIT HUP INT TERM
-
-$TMUX kill-server 2>/dev/null
-$TMUX new-session -d -x80 -y20 "sh -c 'printf \"\\033]133;A\\007p\\$ \\033]133;B\\007echo\\n\\033]133;C\\007one\\ntwo\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007broken\\n\\033]133;C\\007unfinished\"; exec sleep 100'" || exit 1
-sleep 1
-
-$TMUX copy-mode || exit 1
-$TMUX send-keys -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = unfinished ] || exit 1
-
-$TMUX send-keys -X pipe-output "wc -c >$OUT" || exit 1
-sleep 1
-[ "$(cat "$OUT")" = 10 ] || exit 1
-
-$TMUX send-keys -X copy-pipe-output "wc -c >$OUT" output || exit 1
-sleep 1
-[ "$(cat "$OUT")" = 10 ] || exit 1
-[ "$($TMUX show-buffer)" = unfinished ] || exit 1
-
-$TMUX send-keys -X select-output || exit 1
-$TMUX send-keys -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = unfinished ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX copy-mode || exit 1
-$TMUX send-keys -X select-output || exit 1
-$TMUX send-keys -X pipe-selection "wc -c >$OUT" || exit 1
-sleep 1
-[ "$(cat "$OUT")" = 10 ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX copy-mode || exit 1
-$TMUX send-keys -X search-backward separator || exit 1
-$TMUX send-keys -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = "$EXPECTED" ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX copy-mode -c || exit 1
-$TMUX send-keys -X search-backward echo || exit 1
-$TMUX send-keys -X select-output || exit 1
-$TMUX send-keys -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = "$EXPECTED" ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX copy-mode || exit 1
-$TMUX send-keys -X search-backward one || exit 1
-$TMUX send-keys -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = "$EXPECTED" ] || exit 1
-$TMUX send-keys -X cancel || exit 1
-
-$TMUX new-window -d -n plain "printf 'alpha\\nbeta\\n'; exec sleep 100" || exit 1
-sleep 1
-$TMUX copy-mode -t :plain || exit 1
-$TMUX send-keys -t :plain.0 -X copy-output -a || exit 1
-all=$($TMUX show-buffer)
-case "$all" in
-*alpha*beta*) ;;
-*) exit 1 ;;
-esac
-$TMUX send-keys -t :plain.0 -X cancel || exit 1
-
-$TMUX set-buffer -b keep unchanged || exit 1
-$TMUX copy-mode -t :plain || exit 1
-$TMUX send-keys -t :plain.0 -X copy-output || exit 1
-[ "$($TMUX show-buffer -b keep)" = unchanged ] || exit 1
-$TMUX send-keys -t :plain.0 -X cancel || exit 1
-
-$TMUX new-window -d -n empty "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007true\\033]133;C\\033]133;D;0\\007'; exec sleep 100" || exit 1
-sleep 1
-$TMUX copy-mode -t :empty || exit 1
-$TMUX send-keys -t :empty.0 -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
-$TMUX send-keys -t :empty.0 -X cancel || exit 1
-
-$TMUX new-window -d -n prompt "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
-sleep 1
-$TMUX copy-mode -t :prompt || exit 1
-$TMUX send-keys -t :prompt.0 -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
-$TMUX send-keys -t :prompt.0 -X cancel || exit 1
-
-$TMUX copy-mode -c -t :prompt || exit 1
-$TMUX send-keys -t :prompt.0 -X expand-output || exit 1
-$TMUX send-keys -t :prompt.0 -X -N 100 cursor-down || exit 1
-$TMUX send-keys -t :prompt.0 -X select-output || exit 1
-[ "$($TMUX display-message -p -t :prompt.0 '#{selection_present}')" = 1 ] || exit 1
-$TMUX send-keys -t :prompt.0 -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
-$TMUX send-keys -t :prompt.0 -X cancel || exit 1
-
-$TMUX copy-mode -t :prompt || exit 1
-$TMUX send-keys -t :prompt.0 -X -N 100 cursor-down || exit 1
-$TMUX send-keys -t :prompt.0 C-o || exit 1
-[ "$($TMUX display-message -p -t :prompt.0 '#{selection_present}')" = 1 ] || exit 1
-$TMUX send-keys -t :prompt.0 -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
-$TMUX send-keys -t :prompt.0 -X cancel || exit 1
-
-$TMUX new-window -d -n same "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\n\\033]133;C\\007one\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
-sleep 1
-$TMUX copy-mode -t :same || exit 1
-$TMUX send-keys -t :same.0 -X search-backward one || exit 1
-$TMUX send-keys -t :same.0 -X select-output || exit 1
-$TMUX send-keys -t :same.0 -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
-$TMUX send-keys -t :same.0 -X cancel || exit 1
-
-$TMUX new-window -d -n clear "printf 'old1\\nold2\\nold3\\nold4\\nold5\\nold6\\n\\033]133;A\\007p\\$ \\033]133;B\\007echo 1; clear; ps\\n\\033]133;C\\0071\\n\\033[H\\033[2JPID TTY\\n1 pts/0\\n\\033]133;D;0\\007separator\\n\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
-sleep 1
-$TMUX copy-mode -t :clear || exit 1
-$TMUX send-keys -t :clear.0 C-o || exit 1
-$TMUX send-keys -t :clear.0 -X copy-selection || exit 1
-[ "$($TMUX show-buffer)" = "$(printf 'PID TTY\n1 pts/0')" ] || exit 1
-$TMUX send-keys -t :clear.0 -X cancel || exit 1
-
-exit 0
--- a/screen-write.c
+++ b/screen-write.c
@@ -439,6 +439,7 @@ screen_write_reset(struct screen_write_ctx *ctx)

 	if (options_get_number(global_options, "extended-keys") == 2)
 		s->mode = (s->mode & ~EXTENDED_KEY_MODES)|MODE_KEYS_EXTENDED;
+	input_kitty_reset(s);

 	screen_write_clearscreen(ctx, 8);
 	screen_write_set_cursor(ctx, 0, 0);
--- a/screen.c
+++ b/screen.c
@@ -88,6 +88,8 @@ screen_init(struct screen *s, u_int sx, u_int sy, u_int hlimit)
 	s->default_cstyle = SCREEN_CURSOR_DEFAULT;
 	s->mode = MODE_CURSOR;
 	s->default_mode = 0;
+	memset(&s->kitty_keys, 0, sizeof s->kitty_keys);
+	memset(&s->saved_kitty_keys, 0, sizeof s->saved_kitty_keys);
 	s->ccolour = -1;
 	s->default_ccolour = -1;
 	s->tabs = NULL;
@@ -118,9 +120,9 @@ screen_reinit(struct screen *s, int check)

 	if (options_get_number(global_options, "extended-keys") == 2)
 		s->mode = (s->mode & ~EXTENDED_KEY_MODES)|MODE_KEYS_EXTENDED;
-
 	if (SCREEN_IS_ALTERNATE(s))
 		screen_alternate_off(s, NULL, 0);
+	input_kitty_reset(s);
 	s->saved_cx = UINT_MAX;
 	s->saved_cy = UINT_MAX;

@@ -698,6 +700,7 @@ screen_alternate_on(struct screen *s, struct grid_cell *gc, int cursor)

 	if (SCREEN_IS_ALTERNATE(s))
 		return 0;
+	input_kitty_alternate_on(s);
 	sx = screen_size_x(s);
 	sy = screen_size_y(s);

@@ -758,6 +761,7 @@ screen_alternate_off(struct screen *s, struct grid_cell *gc, int cursor)
 			s->cy = screen_size_y(s) - 1;
 		return 0;
 	}
+	input_kitty_alternate_off(s);

 	/* Restore the saved grid. */
 	grid_duplicate_lines(s->grid, screen_hsize(s), s->saved_grid, 0,
--- a/server-client.c
+++ b/server-client.c
@@ -2194,6 +2194,7 @@ server_client_reset_state(struct client *c)
 		log_debug("%s: client %s mode %s", __func__, c->name,
 		    screen_mode_to_string(mode));
 	}
+	tty_update_kitty(tty, s);

 	/* Reset region and margin. */
 	tty_region_off(tty);
--- a/spawn.c
+++ b/spawn.c
@@ -701,7 +701,7 @@ spawn_editor_finish(struct window_pane *wp)

 struct spawn_editor_state *
 spawn_editor(struct client *c, const char *buf, size_t len,
-    const char *editor, spawn_finish_edit_cb cb, void *arg)
+    spawn_finish_edit_cb cb, void *arg)
 {
 	struct spawn_editor_state	*es;
 	struct spawn_context		 sc = { 0 };
@@ -715,13 +715,13 @@ spawn_editor(struct client *c, const char *buf, size_t len,
 	FILE				*f;
 	char				*cmd, *cause = NULL;
 	char				 path[] = _PATH_TMP "tmux.XXXXXXXX";
+	const char			*editor;
 	int				 fd;

 	if (w->modal != NULL)
 		return (NULL);

-	if (editor == NULL)
-		editor = options_get_string(global_options, "editor");
+	editor = options_get_string(global_options, "editor");
 	fd = mkstemp(path);
 	if (fd == -1)
 		return (NULL);
--- a/tmux.1
+++ b/tmux.1
@@ -2006,25 +2006,6 @@ Same as
 .Ic copy\-pipe
 but also exit copy mode.
 .It Xo
-.Ic copy\-pipe\-output
-.Op Fl aCP
-.Op Ar command
-.Op Ar prefix
-.Xc
-Copy the current OSC 133 command output, pipe it to
-.Ar command ,
-and clear the selection.
-.Ar prefix
-is used to name the new paste buffer.
-.It Xo
-.Ic copy\-output
-.Op Fl aCP
-.Op Ar prefix
-.Xc
-Copy the current OSC 133 command output and clear the selection.
-.Ar prefix
-is used to name the new paste buffer.
-.It Xo
 .Ic copy\-selection
 .Op Fl CP
 .Op Ar prefix
@@ -2190,27 +2171,6 @@ Hide line numbers in copy mode.
 .Xc
 Toggle line numbers in copy mode.
 .It Xo
-.Ic collapse\-output
-.Op Fl a
-.Xc
-Collapse the output for the command on the cursor line.
-With
-.Fl a ,
-collapse all command output in the copy-mode buffer.
-Text before the first OSC 133 prompt is treated as an initial command output
-region.
-.It Xo
-.Ic expand\-output
-.Op Fl a
-.Xc
-Expand the output for the command on the cursor line.
-With
-.Fl a ,
-expand all command output in the copy-mode buffer.
-.Pp
-The Tab key toggles output for the command on the cursor line and S-Tab
-toggles all command output.
-.It Xo
 .Ic middle\-line
 (vi: M)
 (emacs: M\-r)
@@ -2264,32 +2224,6 @@ but treat all non-whitespace characters as part of a word.
 .Xc
 Switch at which end of the selection the cursor sits.
 .It Xo
-.Ic open\-output
-.Op Fl a
-.Op Ar command
-.Xc
-Open the current OSC 133 command output in an editor.
-If
-.Ar command
-is given, it is used as the editor command; otherwise, the
-.Ic editor
-option is used.
-.It Xo
-.Ic open\-selection
-.Op Ar command
-.Xc
-Open the current selection in an editor.
-If
-.Ar command
-is given, it is used as the editor command; otherwise, the
-.Ic editor
-option is used.
-In emacs mode,
-.Ql e ,
-and in vi mode,
-.Ql M\-e ,
-opens the selection if one is present, otherwise the command output.
-.It Xo
 .Ic page\-down
 (vi: C\-f)
 (emacs: PageDown)
@@ -2330,21 +2264,6 @@ Same as
 .Ic pipe
 but also exit copy mode.
 .It Xo
-.Ic pipe\-output
-.Op Fl a
-.Op Ar command
-.Xc
-Pipe the current OSC 133 command output to
-.Ar command
-and clear the selection.
-.It Xo
-.Ic pipe\-selection
-.Op Ar command
-.Xc
-Pipe the selected text to
-.Ar command
-and clear the selection.
-.It Xo
 .Ic previous\-matching\-bracket
 (emacs: M\-C\-b)
 .Xc
@@ -2534,15 +2453,6 @@ Search forward for the specified plain text.
 Repeat the last search in the reverse direction (forward becomes backward and
 backward becomes forward).
 .It Xo
-.Ic select\-output
-.Op Fl a
-.Xc
-Select the current OSC 133 command output.
-The default emacs binding is
-.Ql C\-o
-and the default vi binding is
-.Ql M\-o .
-.It Xo
 .Ic select\-line
 (vi: V)
 .Xc
@@ -2586,20 +2496,6 @@ Toggle the visibility of the position indicator in the top right.
 Move to the top line.
 .El
 .Pp
-The output commands use OSC 133 output text from the
-.Ql C
-marker up to its matching
-.Ql D
-marker.
-If there is no
-.Ql D
-marker, the output ends at the end of the copy-mode buffer.
-At the following prompt or below it, they use the most recent nonempty output.
-With
-.Fl a ,
-they use the entire copy-mode buffer instead.
-If no output range can be found, they do nothing.
-.Pp
 The search commands come in several varieties:
 .Ql search\-forward
 and
@@ -2707,19 +2603,12 @@ The synopsis for the
 command is:
 .Bl -tag -width Ds
 .It Xo Ic copy\-mode
-.Op Fl UcdekHMqSu
+.Op Fl dekHMqSu
 .Op Fl s Ar src\-pane
 .Op Fl t Ar target\-pane
 .Xc
 Enter copy mode.
 .Pp
-.Fl c
-enters copy mode with OSC 133 command output collapsed.
-.Fl U
-enters copy mode with OSC 133 output controls shown and all output expanded.
-When output is collapsed, the prompt and entered command are shown and text
-from the output start marker to the next primary prompt marker is hidden.
-.Pp
 .Fl u
 enters copy mode and scrolls one page up and
 .Fl d
@@ -5018,14 +4907,30 @@ If enabled, the server will exit when there are no attached clients.
 .It Xo Ic extended\-keys
 .Op Ic on | off | always
 .Xc
-Controls how modified keys (keys pressed together with Control, Meta, or Shift)
-are reported.
-This is the equivalent of the
+Controls how modified keys are reported.
+When enabled,
+.Nm
+uses the Kitty keyboard protocol with terminals which support it, and the
 .Ic modifyOtherKeys
 .Xr xterm 1
-resource.
+resource with other terminals which support extended keys.
+Each client uses the best that its terminal supports, so clients with different
+terminals may be attached at the same time.
 .Pp
-When set to
+Programs inside panes may request either the Kitty keyboard protocol or
+.Ic modifyOtherKeys ,
+and keys are sent to each program in the form it requested, whichever client
+they were typed on.
+The Kitty keyboard protocol can report the Super and Hyper modifiers, whose key
+name prefixes are
+.Ql s-
+and
+.Ql H- ;
+its disambiguate and report-all enhancements are supported.
+.Pp
+For
+.Ic modifyOtherKeys ,
+when set to
 .Ic on ,
 the program inside the pane can request one of two modes: mode 1 which changes
 the sequence for only keys which lack an existing well-known representation; or
@@ -5034,26 +4939,35 @@ When set to
 .Ic always ,
 modes 1 and 2 can still be requested by applications, but mode 1 will be forced
 instead of the standard mode.
+This applies only to applications inside panes; it does not force the Kitty
+keyboard protocol or change what
+.Nm
+requests from the terminal.
 When set to
 .Ic off ,
 this feature is disabled and only standard keys are reported.
 .Pp
 .Nm
 will always request extended keys itself if the terminal supports them.
+Support for the Kitty keyboard protocol is detected when a client attaches.
 See also the
+.Ic kittykeys
+and
 .Ic extkeys
-feature for the
+features for the
 .Ic terminal\-features
 option, the
 .Ic extended\-keys\-format
 option and the
 .Ic pane_key_mode
-variable.
+and
+.Ic client_key_mode
+variables.
 .It Xo Ic extended\-keys\-format
-.Op Ic csi\-u | xterm
+.Op Ic csi\-u | xterm | kitty
 .Xc
-Selects one of the two possible formats for reporting modified keys to
-applications.
+Selects the format for reporting modified keys to programs which request
+.Ic modifyOtherKeys .
 This is the equivalent of the
 .Ic formatOtherKeys
 .Xr xterm 1
@@ -5066,6 +4980,11 @@ and as
 .Ql \[ha][[65;6u
 when set to
 .Ic csi\-u .
+.Ic kitty
+is accepted for compatibility and is the same as
+.Ic csi\-u ;
+programs which request the Kitty keyboard protocol receive it whatever this
+option is set to.
 .It Xo Ic focus\-events
 .Op Ic on | off
 .Xc
@@ -5214,6 +5133,9 @@ Ignore function keys from
 and use the
 .Nm
 internal set only.
+.It kittykeys
+Supports the Kitty keyboard protocol.
+This is added automatically if the terminal answers the Kitty keyboard query.
 .It margins
 Supports DECSLRM margins.
 .It mouse
@@ -5920,20 +5842,6 @@ section.
 .It Ic copy\-mode\-position\-format Ar format
 Format of the position indicator in copy mode.
 .Pp
-.It Ic copy\-mode\-exit\-status\-format Ar format
-Format of the OSC 133 exit status indicator in the copy-mode gutter.
-The default displays a theme red
-.Ql !
-for a nonzero status and a space otherwise.
-The gutter grows to fit the expanded format.
-The format is drawn to the left of the collapse control, and its alignment
-applies within that area.
-The format is expanded with
-.Ql exit_status
-and
-.Ql exit_status_present ,
-which is set only when the OSC 133 end-of-output marker includes a status.
-.Pp
 .It Ic copy\-mode\-position\-style Ar style
 Set the style of the position indicator in copy mode.
 For how to specify
@@ -7434,6 +7342,7 @@ The following variables are available, where appropriate:
 .It Li "client_discarded" Ta "" Ta "Bytes discarded when client behind"
 .It Li "client_flags" Ta "" Ta "List of client flags"
 .It Li "client_height" Ta "" Ta "Height of client"
+.It Li "client_key_mode" Ta "" Ta "Extended key reporting mode for this client"
 .It Li "client_key_table" Ta "" Ta "Current key table"
 .It Li "client_last_session" Ta "" Ta "Name of the client's last session"
 .It Li "client_name" Ta "" Ta "Name of client"
--- a/tmux.h
+++ b/tmux.h
@@ -142,6 +142,8 @@ struct winlink;
 #define VISUAL_BOTH 2

 /* Key modifier bits. */
+#define KEYC_SUPER           0x00010000000000ULL
+#define KEYC_HYPER           0x00020000000000ULL
 #define KEYC_META            0x00100000000000ULL
 #define KEYC_CTRL            0x00200000000000ULL
 #define KEYC_SHIFT           0x00400000000000ULL
@@ -374,6 +376,29 @@ enum {
 	KEYC_F10,
 	KEYC_F11,
 	KEYC_F12,
+	KEYC_F13,
+	KEYC_F14,
+	KEYC_F15,
+	KEYC_F16,
+	KEYC_F17,
+	KEYC_F18,
+	KEYC_F19,
+	KEYC_F20,
+	KEYC_F21,
+	KEYC_F22,
+	KEYC_F23,
+	KEYC_F24,
+	KEYC_F25,
+	KEYC_F26,
+	KEYC_F27,
+	KEYC_F28,
+	KEYC_F29,
+	KEYC_F30,
+	KEYC_F31,
+	KEYC_F32,
+	KEYC_F33,
+	KEYC_F34,
+	KEYC_F35,
 	KEYC_IC,
 	KEYC_DC,
 	KEYC_HOME,
@@ -405,6 +430,54 @@ enum {
 	KEYC_KP_ENTER,
 	KEYC_KP_ZERO,
 	KEYC_KP_PERIOD,
+	KEYC_KP_EQUAL,
+	KEYC_KP_SEPARATOR,
+	KEYC_KP_LEFT,
+	KEYC_KP_RIGHT,
+	KEYC_KP_UP,
+	KEYC_KP_DOWN,
+	KEYC_KP_PPAGE,
+	KEYC_KP_NPAGE,
+	KEYC_KP_HOME,
+	KEYC_KP_END,
+	KEYC_KP_IC,
+	KEYC_KP_DC,
+	KEYC_KP_BEGIN,
+
+	/* Other function keys. */
+	KEYC_CAPSLOCK,
+	KEYC_SCROLLLOCK,
+	KEYC_NUMLOCK,
+	KEYC_PRINTSCREEN,
+	KEYC_PAUSE,
+	KEYC_MENU,
+	KEYC_MEDIA_PLAY,
+	KEYC_MEDIA_PAUSE,
+	KEYC_MEDIA_PLAYPAUSE,
+	KEYC_MEDIA_REVERSE,
+	KEYC_MEDIA_STOP,
+	KEYC_MEDIA_FASTFORWARD,
+	KEYC_MEDIA_REWIND,
+	KEYC_MEDIA_NEXT,
+	KEYC_MEDIA_PREVIOUS,
+	KEYC_MEDIA_RECORD,
+	KEYC_VOLUME_DOWN,
+	KEYC_VOLUME_UP,
+	KEYC_VOLUME_MUTE,
+	KEYC_LEFT_SHIFT,
+	KEYC_LEFT_CTRL,
+	KEYC_LEFT_ALT,
+	KEYC_LEFT_SUPER,
+	KEYC_LEFT_HYPER,
+	KEYC_LEFT_META,
+	KEYC_RIGHT_SHIFT,
+	KEYC_RIGHT_CTRL,
+	KEYC_RIGHT_ALT,
+	KEYC_RIGHT_SUPER,
+	KEYC_RIGHT_HYPER,
+	KEYC_RIGHT_META,
+	KEYC_ISO_LEVEL3_SHIFT,
+	KEYC_ISO_LEVEL5_SHIFT,

 	/* Theme reporting. */
 	KEYC_REPORT_DARK_THEME,
@@ -702,6 +775,16 @@ enum tty_code_code {
 #define CURSOR_MODES (MODE_CURSOR|MODE_CURSOR_BLINKING|MODE_CURSOR_VERY_VISIBLE)
 #define EXTENDED_KEY_MODES (MODE_KEYS_EXTENDED|MODE_KEYS_EXTENDED_2)

+/* Extended key output formats. */
+#define EXTENDED_KEYS_CSI_U 0
+#define EXTENDED_KEYS_XTERM 1
+#define EXTENDED_KEYS_KITTY 2
+
+/* Supported Kitty keyboard protocol flags. */
+#define KITTY_KEY_DISAMBIGUATE 0x1
+#define KITTY_KEY_REPORT_ALL 0x8
+#define KITTY_KEY_SUPPORTED (KITTY_KEY_DISAMBIGUATE|KITTY_KEY_REPORT_ALL)
+
 /* Mouse protocol constants. */
 #define MOUSE_PARAM_MAX 0xff
 #define MOUSE_PARAM_UTF8_MAX 0x7ff
@@ -816,7 +899,6 @@ struct colour_palette {
 #define GRID_LINE_START_OUTPUT 0x40
 #define GRID_LINE_END_OUTPUT 0x80
 #define GRID_LINE_HYPERLINK 0x100
-#define GRID_LINE_END_OUTPUT_STATUS 0x200

 /* All OSC 133 flags. */
 #define GRID_LINE_OSC133_FLAGS \
@@ -824,8 +906,7 @@ struct colour_palette {
 	 GRID_LINE_SECOND_PROMPT| \
 	 GRID_LINE_START_COMMAND| \
 	 GRID_LINE_START_OUTPUT| \
-	 GRID_LINE_END_OUTPUT| \
-	 GRID_LINE_END_OUTPUT_STATUS)
+	 GRID_LINE_END_OUTPUT)

 /* Grid string flags. */
 #define GRID_STRING_WITH_SEQUENCES 0x1
@@ -1070,6 +1151,11 @@ struct progress_bar {
 /* Virtual screen. */
 struct screen_sel;
 struct screen_titles;
+struct kitty_key_state {
+	u_int	flags;
+	u_int	saved_flags;
+	int	have_saved;
+};
 struct screen {
 	char				*title;
 	char				*path;
@@ -1091,6 +1177,8 @@ struct screen {

 	int				 mode;
 	int				 default_mode;
+	struct kitty_key_state		 kitty_keys;
+	struct kitty_key_state		 saved_kitty_keys;

 	u_int				 saved_cx;
 	u_int				 saved_cy;
@@ -1741,6 +1829,7 @@ struct tty_term {
 #define TERM_VT100LIKE 0x20
 #define TERM_SIXEL 0x40
 #define TERM_INVALIDMS 0x80
+#define TERM_KITTYKEYS 0x100
 	int		 flags;

 	LIST_ENTRY(tty_term) entry;
@@ -1821,9 +1910,12 @@ struct tty {
 #define TTY_WAITBG 0x4000
 #define TTY_BRACKETPASTE 0x8000
 #define TTY_HAVESYNC 0x10000
+#define TTY_HAVEKKB 0x20000
+#define TTY_KKBPUSHED 0x40000
 #define TTY_ALL_REQUEST_FLAGS \
-	(TTY_HAVEDA|TTY_HAVEDA2|TTY_HAVEXDA|TTY_HAVESYNC)
+	(TTY_HAVEDA|TTY_HAVEDA2|TTY_HAVEXDA|TTY_HAVESYNC|TTY_HAVEKKB)
 	int		 flags;
+	u_int		 kitty_keys;

 	struct tty_term	*term;

@@ -2976,6 +3068,7 @@ int	tty_open(struct tty *, char **);
 void	tty_close(struct tty *);
 void	tty_free(struct tty *);
 void	tty_update_features(struct tty *);
+void	tty_update_kitty(struct tty *, struct screen *);
 void	tty_set_selection(struct tty *, const char *, const char *, size_t);
 void	tty_write(void (*)(struct tty *, const struct tty_ctx *),
 	    struct tty_ctx *);
@@ -3457,6 +3550,20 @@ int	 input_key(struct screen *, struct bufferevent *, key_code);
 int	 input_key_get_mouse(struct screen *, struct mouse_event *, u_int,
 	     u_int, const char **, size_t *);

+/* input-kitty.c */
+void	 input_kitty_reset(struct screen *);
+void	 input_kitty_alternate_on(struct screen *);
+void	 input_kitty_alternate_off(struct screen *);
+void	 input_kitty_set(struct screen *, u_int, int);
+void	 input_kitty_push(struct screen *, u_int);
+void	 input_kitty_pop(struct screen *, u_int);
+int	 input_key_kitty(struct screen *, struct bufferevent *, key_code);
+
+/* tty-kitty.c */
+int	 tty_keys_kitty(struct tty *, const char *, size_t, size_t *,
+	     key_code *);
+int	 tty_keys_kitty_query(struct tty *, const char *, size_t, size_t *);
+
 /* colour.c */
 int	 colour_find_rgb(u_char, u_char, u_char);
 int	 colour_join_rgb(u_char, u_char, u_char);
@@ -4229,7 +4336,7 @@ struct winlink	*spawn_window(struct spawn_context *, char **);
 struct window_pane *spawn_pane(struct spawn_context *, char **);
 typedef void (*spawn_finish_edit_cb)(char *, size_t, void *);
 struct spawn_editor_state *spawn_editor(struct client *, const char *, size_t,
-		     const char *, spawn_finish_edit_cb, void *);
+		     spawn_finish_edit_cb, void *);
 void		 spawn_cancel_editor(struct spawn_editor_state *);
 pid_t		 spawn_get_editor_pid(struct spawn_editor_state *);
 void		 spawn_editor_finish(struct window_pane *);
--- a/tty-features.c
+++ b/tty-features.c
@@ -235,6 +235,13 @@ static const struct tty_feature tty_feature_sync = {
 	0
 };

+/* Terminal supports the Kitty keyboard protocol. */
+static const struct tty_feature tty_feature_kittykeys = {
+	"kittykeys",
+	NULL,
+	TERM_KITTYKEYS
+};
+
 /* Terminal supports extended keys. */
 static const char *const tty_feature_extkeys_capabilities[] = {
 	"Eneks=\\E[>4;2m",
@@ -386,6 +393,7 @@ static const struct tty_feature *const tty_features[] = {
 	&tty_feature_extkeys,
 	&tty_feature_focus,
 	&tty_feature_ignorefkeys,
+	&tty_feature_kittykeys,
 	&tty_feature_margins,
 	&tty_feature_mouse,
 	&tty_feature_osc7,
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -772,6 +772,17 @@ tty_keys_next(struct tty *tty)
 		goto partial_key;
 	}

+	/* Is this a Kitty keyboard protocol response? */
+	switch (tty_keys_kitty_query(tty, buf, len, &size)) {
+	case 0:		/* yes */
+		key = KEYC_UNKNOWN;
+		goto complete_key;
+	case -1:	/* no, or not valid */
+		break;
+	case 1:		/* partial */
+		goto partial_key;
+	}
+
 	/* Is this a synchronized update mode response? */
 	switch (tty_keys_sync(tty, buf, len, &size)) {
 	case 0:		/* yes */
@@ -858,6 +869,18 @@ tty_keys_next(struct tty *tty)
 		goto partial_key;
 	}

+	/* Is this an extended key press? */
+	switch (tty_keys_kitty(tty, buf, len, &size, &key)) {
+	case 0:		/* yes */
+		goto complete_key;
+	case -1:	/* no, or not valid */
+		break;
+	case -2:	/* yes, but not representable by tmux */
+		goto discard_key;
+	case 1:		/* partial */
+		goto partial_key;
+	}
+
 	/* Is this an extended key press? */
 	switch (tty_keys_extended_key(tty, buf, len, &size, &key)) {
 	case 0:		/* yes */
@@ -1089,6 +1112,8 @@ tty_keys_extended_key(struct tty *tty, const char *buf, size_t len,
 	utf8_char	 uc;

 	*size = 0;
+	if (tty->flags & TTY_KKBPUSHED)
+		return (-1);

 	/* First two bytes are always \033[. */
 	if (buf[0] != '\033')
@@ -1527,6 +1552,8 @@ tty_keys_device_attributes(struct tty *tty, const char *buf, size_t len,
 	}
 	log_debug("%s: received primary DA %.*s", c->name, (int)*size, buf);

+	/* A DA response without a preceding keyboard response means no support. */
+	tty->flags |= TTY_HAVEKKB;
 	tty_update_features(tty);
 	tty->flags |= TTY_HAVEDA;

--- a/tty-kitty.c
+++ b/tty-kitty.c
@@ -0,0 +1,430 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2026 Michael Grant <mgrant@grant.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <ctype.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tmux.h"
+
+/* Detect support in the outside terminal and decode its key sequences. */
+
+struct tty_kitty_key {
+	u_int		 number;
+	key_code	 key;
+};
+
+static const struct tty_kitty_key tty_kitty_keys[] = {
+	{ 57358, KEYC_CAPSLOCK },
+	{ 57359, KEYC_SCROLLLOCK },
+	{ 57360, KEYC_NUMLOCK },
+	{ 57361, KEYC_PRINTSCREEN },
+	{ 57362, KEYC_PAUSE },
+	{ 57363, KEYC_MENU },
+	{ 57376, KEYC_F13 },
+	{ 57377, KEYC_F14 },
+	{ 57378, KEYC_F15 },
+	{ 57379, KEYC_F16 },
+	{ 57380, KEYC_F17 },
+	{ 57381, KEYC_F18 },
+	{ 57382, KEYC_F19 },
+	{ 57383, KEYC_F20 },
+	{ 57384, KEYC_F21 },
+	{ 57385, KEYC_F22 },
+	{ 57386, KEYC_F23 },
+	{ 57387, KEYC_F24 },
+	{ 57388, KEYC_F25 },
+	{ 57389, KEYC_F26 },
+	{ 57390, KEYC_F27 },
+	{ 57391, KEYC_F28 },
+	{ 57392, KEYC_F29 },
+	{ 57393, KEYC_F30 },
+	{ 57394, KEYC_F31 },
+	{ 57395, KEYC_F32 },
+	{ 57396, KEYC_F33 },
+	{ 57397, KEYC_F34 },
+	{ 57398, KEYC_F35 },
+	{ 57399, KEYC_KP_ZERO|KEYC_KEYPAD },
+	{ 57400, KEYC_KP_ONE|KEYC_KEYPAD },
+	{ 57401, KEYC_KP_TWO|KEYC_KEYPAD },
+	{ 57402, KEYC_KP_THREE|KEYC_KEYPAD },
+	{ 57403, KEYC_KP_FOUR|KEYC_KEYPAD },
+	{ 57404, KEYC_KP_FIVE|KEYC_KEYPAD },
+	{ 57405, KEYC_KP_SIX|KEYC_KEYPAD },
+	{ 57406, KEYC_KP_SEVEN|KEYC_KEYPAD },
+	{ 57407, KEYC_KP_EIGHT|KEYC_KEYPAD },
+	{ 57408, KEYC_KP_NINE|KEYC_KEYPAD },
+	{ 57409, KEYC_KP_PERIOD|KEYC_KEYPAD },
+	{ 57410, KEYC_KP_SLASH|KEYC_KEYPAD },
+	{ 57411, KEYC_KP_STAR|KEYC_KEYPAD },
+	{ 57412, KEYC_KP_MINUS|KEYC_KEYPAD },
+	{ 57413, KEYC_KP_PLUS|KEYC_KEYPAD },
+	{ 57414, KEYC_KP_ENTER|KEYC_KEYPAD },
+	{ 57415, KEYC_KP_EQUAL|KEYC_KEYPAD },
+	{ 57416, KEYC_KP_SEPARATOR|KEYC_KEYPAD },
+	{ 57417, KEYC_KP_LEFT|KEYC_KEYPAD },
+	{ 57418, KEYC_KP_RIGHT|KEYC_KEYPAD },
+	{ 57419, KEYC_KP_UP|KEYC_KEYPAD },
+	{ 57420, KEYC_KP_DOWN|KEYC_KEYPAD },
+	{ 57421, KEYC_KP_PPAGE|KEYC_KEYPAD },
+	{ 57422, KEYC_KP_NPAGE|KEYC_KEYPAD },
+	{ 57423, KEYC_KP_HOME|KEYC_KEYPAD },
+	{ 57424, KEYC_KP_END|KEYC_KEYPAD },
+	{ 57425, KEYC_KP_IC|KEYC_KEYPAD },
+	{ 57426, KEYC_KP_DC|KEYC_KEYPAD },
+	{ 57427, KEYC_KP_BEGIN|KEYC_KEYPAD },
+	{ 57428, KEYC_MEDIA_PLAY },
+	{ 57429, KEYC_MEDIA_PAUSE },
+	{ 57430, KEYC_MEDIA_PLAYPAUSE },
+	{ 57431, KEYC_MEDIA_REVERSE },
+	{ 57432, KEYC_MEDIA_STOP },
+	{ 57433, KEYC_MEDIA_FASTFORWARD },
+	{ 57434, KEYC_MEDIA_REWIND },
+	{ 57435, KEYC_MEDIA_NEXT },
+	{ 57436, KEYC_MEDIA_PREVIOUS },
+	{ 57437, KEYC_MEDIA_RECORD },
+	{ 57438, KEYC_VOLUME_DOWN },
+	{ 57439, KEYC_VOLUME_UP },
+	{ 57440, KEYC_VOLUME_MUTE },
+	{ 57441, KEYC_LEFT_SHIFT },
+	{ 57442, KEYC_LEFT_CTRL },
+	{ 57443, KEYC_LEFT_ALT },
+	{ 57444, KEYC_LEFT_SUPER },
+	{ 57445, KEYC_LEFT_HYPER },
+	{ 57446, KEYC_LEFT_META },
+	{ 57447, KEYC_RIGHT_SHIFT },
+	{ 57448, KEYC_RIGHT_CTRL },
+	{ 57449, KEYC_RIGHT_ALT },
+	{ 57450, KEYC_RIGHT_SUPER },
+	{ 57451, KEYC_RIGHT_HYPER },
+	{ 57452, KEYC_RIGHT_META },
+	{ 57453, KEYC_ISO_LEVEL3_SHIFT },
+	{ 57454, KEYC_ISO_LEVEL5_SHIFT }
+};
+
+static int
+tty_kitty_parse_number(const char *s, u_int *value, int empty)
+{
+	char		*end;
+	unsigned long	 number;
+
+	if (*s == '\0') {
+		if (!empty)
+			return (-1);
+		return (0);
+	}
+	if (!isdigit((u_char)*s))
+		return (-1);
+	number = strtoul(s, &end, 10);
+	if (*end != '\0' || number > UINT_MAX)
+		return (-1);
+	*value = number;
+	return (0);
+}
+
+static int
+tty_kitty_parse_list(char *s, u_int *first, u_int *second, int empty,
+    u_int maximum)
+{
+	char	*copy, *item;
+	u_int	 n = 0, value;
+	int	 result = 0;
+
+	copy = s;
+	while ((item = strsep(&copy, ":")) != NULL) {
+		if (maximum != 0 && n == maximum)
+			return (-1);
+		value = 0;
+		if (tty_kitty_parse_number(item, &value, empty) != 0) {
+			result = -1;
+			break;
+		}
+		if (n == 0 && *item != '\0')
+			*first = value;
+		else if (n == 1 && *item != '\0')
+			*second = value;
+		n++;
+	}
+	return (result);
+}
+
+static int
+tty_kitty_find_end(const char *buf, size_t len, size_t *end)
+{
+	size_t	i;
+
+	for (i = 2; i < len; i++) {
+		if (buf[i] == 'u' || buf[i] == '~' || buf[i] == 'A' ||
+		    buf[i] == 'B' || buf[i] == 'C' || buf[i] == 'D' ||
+		    buf[i] == 'E' || buf[i] == 'F' || buf[i] == 'H' ||
+		    buf[i] == 'P' || buf[i] == 'Q' || buf[i] == 'S') {
+			*end = i;
+			return (0);
+		}
+		if (!isdigit((u_char)buf[i]) && buf[i] != ';' && buf[i] != ':')
+			return (-1);
+	}
+	return (1);
+}
+
+static key_code
+tty_kitty_function(u_int number, char final)
+{
+	u_int	i;
+
+	if (final == 'u') {
+		switch (number) {
+		case 9:
+			return (C0_HT);
+		case 13:
+			return (C0_CR);
+		case 27:
+			return (C0_ESC);
+		case 127:
+			return (KEYC_BSPACE);
+		}
+		for (i = 0; i < nitems(tty_kitty_keys); i++) {
+			if (tty_kitty_keys[i].number == number)
+				return (tty_kitty_keys[i].key);
+		}
+		return (KEYC_NONE);
+	}
+
+	if (final == '~') {
+		switch (number) {
+		case 2: return (KEYC_IC);
+		case 3: return (KEYC_DC);
+		case 5: return (KEYC_PPAGE);
+		case 6: return (KEYC_NPAGE);
+		case 7: return (KEYC_HOME);
+		case 8: return (KEYC_END);
+		case 11: return (KEYC_F1);
+		case 12: return (KEYC_F2);
+		case 13: return (KEYC_F3);
+		case 14: return (KEYC_F4);
+		case 15: return (KEYC_F5);
+		case 17: return (KEYC_F6);
+		case 18: return (KEYC_F7);
+		case 19: return (KEYC_F8);
+		case 20: return (KEYC_F9);
+		case 21: return (KEYC_F10);
+		case 23: return (KEYC_F11);
+		case 24: return (KEYC_F12);
+		case 29: return (KEYC_MENU);
+		case 57427: return (KEYC_KP_BEGIN|KEYC_KEYPAD);
+		}
+		return (KEYC_UNKNOWN);
+	}
+	if (number != 1)
+		return (KEYC_UNKNOWN);
+	switch (final) {
+	case 'A': return (KEYC_UP|KEYC_CURSOR);
+	case 'B': return (KEYC_DOWN|KEYC_CURSOR);
+	case 'C': return (KEYC_RIGHT|KEYC_CURSOR);
+	case 'D': return (KEYC_LEFT|KEYC_CURSOR);
+	case 'E': return (KEYC_KP_BEGIN|KEYC_KEYPAD);
+	case 'F': return (KEYC_END);
+	case 'H': return (KEYC_HOME);
+	case 'P': return (KEYC_F1);
+	case 'Q': return (KEYC_F2);
+	case 'S': return (KEYC_F4);
+	}
+	return (KEYC_UNKNOWN);
+}
+
+int
+tty_keys_kitty_query(struct tty *tty, const char *buf, size_t len,
+    size_t *size)
+{
+	struct client	*c = tty->client;
+	size_t		 i;
+	u_int		 flags = 0;
+
+	*size = 0;
+	if (tty->flags & TTY_HAVEKKB)
+		return (-1);
+
+	if (buf[0] != '\033')
+		return (-1);
+	if (len == 1)
+		return (1);
+	if (buf[1] != '[')
+		return (-1);
+	if (len == 2)
+		return (1);
+	if (buf[2] != '?')
+		return (-1);
+	if (len == 3)
+		return (1);
+
+	for (i = 3; i < len && isdigit((u_char)buf[i]); i++) {
+		if (flags > (UINT_MAX - (buf[i] - '0')) / 10)
+			return (-1);
+		flags = (flags * 10) + (buf[i] - '0');
+	}
+	if (i == len)
+		return (1);
+	if (i == 3 || buf[i] != 'u')
+		return (-1);
+
+	*size = i + 1;
+	tty->kitty_keys = flags;
+	tty->flags |= TTY_HAVEKKB;
+	log_debug("%s: received Kitty keyboard flags %u", c->name, flags);
+	tty_parse_client_features(c, "kittykeys", ",");
+	tty_update_features(tty);
+	return (0);
+}
+
+void
+tty_update_kitty(struct tty *tty, struct screen *s)
+{
+	u_int	flags;
+	char	buf[32];
+
+	if (options_get_number(global_options, "extended-keys") == 0 ||
+	    (~tty->term->flags & TERM_KITTYKEYS)) {
+		if (tty->flags & TTY_KKBPUSHED) {
+			tty_puts(tty, "\033[<u");
+			tty->flags &= ~TTY_KKBPUSHED;
+		}
+		return;
+	}
+	flags = KITTY_KEY_DISAMBIGUATE;
+	if (s != NULL && (s->kitty_keys.flags & KITTY_KEY_SUPPORTED) != 0)
+		flags = s->kitty_keys.flags & KITTY_KEY_SUPPORTED;
+	if ((tty->flags & TTY_KKBPUSHED) == 0) {
+		xsnprintf(buf, sizeof buf, "\033[>%uu", flags);
+		tty_puts(tty, buf);
+		tty->flags |= TTY_KKBPUSHED;
+	} else if (tty->kitty_keys != flags) {
+		xsnprintf(buf, sizeof buf, "\033[=%uu", flags);
+		tty_puts(tty, buf);
+	}
+	tty->kitty_keys = flags;
+}
+
+int
+tty_keys_kitty(struct tty *tty, const char *buf, size_t len, size_t *size,
+    key_code *key)
+{
+	struct client	*c = tty->client;
+	struct utf8_data ud;
+	utf8_char	 uc;
+	size_t		 end;
+	char		 tmp[128], *copy, *field, final;
+	u_int		 number = 0, modifiers = 1, event = 1, value;
+	u_int		 fields = 0;
+	key_code	 nkey, onlykey;
+	int		 result;
+
+	*size = 0;
+	if ((tty->flags & TTY_KKBPUSHED) == 0)
+		return (-1);
+	if (len == 0 || buf[0] != '\033')
+		return (-1);
+	if (len == 1)
+		return (1);
+	if (buf[1] != '[')
+		return (-1);
+	if (len == 2)
+		return (1);
+	if (buf[2] == '?')
+		return (-1);
+
+	result = tty_kitty_find_end(buf, len, &end);
+	if (result != 0)
+		return (result);
+	if (end - 2 >= sizeof tmp)
+		return (-1);
+	memcpy(tmp, buf + 2, end - 2);
+	tmp[end - 2] = '\0';
+	final = buf[end];
+	*size = end + 1;
+
+	copy = tmp;
+	while ((field = strsep(&copy, ";")) != NULL) {
+		if (fields == 3)
+			return (-1);
+		value = 0;
+		if (fields == 0) {
+			if (*field == '\0') {
+				if (final == 'u')
+					return (-1);
+				number = 1;
+			} else if (tty_kitty_parse_list(field, &number, &value,
+			    1, 3) != 0)
+				return (-1);
+		} else if (fields == 1) {
+			if (tty_kitty_parse_list(field, &modifiers, &event, 1,
+			    2) != 0)
+				return (-1);
+		} else if (tty_kitty_parse_list(field, &value, &value, 1, 0) != 0)
+			return (-1);
+		fields++;
+	}
+	if (fields == 0 || number == 0 || modifiers == 0)
+		return (-1);
+	if (event == 0 || event == 3 || event > 3)
+		return (-2);
+
+	modifiers--;
+	if (modifiers & 32)
+		return (-2);
+	nkey = tty_kitty_function(number, final);
+	if (nkey == KEYC_NONE) {
+		if (final != 'u')
+			return (-1);
+		if (number >= 57344 && number <= 63743)
+			return (-2);
+		if (number <= 0x7f)
+			nkey = number;
+		else if (utf8_fromwc(number, &ud) != UTF8_DONE ||
+		    utf8_from_data(&ud, &uc) != UTF8_DONE)
+			return (-2);
+		else
+			nkey = uc;
+	} else if (nkey == KEYC_UNKNOWN)
+		return (-1);
+
+	if (modifiers & 1)
+		nkey |= KEYC_SHIFT;
+	if (modifiers & 2)
+		nkey |= KEYC_META|KEYC_IMPLIED_META;
+	if (modifiers & 4)
+		nkey |= KEYC_CTRL;
+	if (modifiers & 8)
+		nkey |= KEYC_SUPER;
+	if (modifiers & 16)
+		nkey |= KEYC_HYPER;
+
+	/* Shift-Tab has a dedicated tmux key code. */
+	onlykey = nkey & KEYC_MASK_KEY;
+	if (onlykey == C0_HT && (nkey & KEYC_SHIFT))
+		nkey = KEYC_BTAB|(nkey & ~KEYC_MASK_KEY & ~KEYC_SHIFT);
+
+	if (log_get_level() != 0) {
+		log_debug("%s: Kitty key %.*s is %llx (%s)", c->name,
+		    (int)*size, buf, nkey, key_string_lookup_key(nkey, 1));
+	}
+	*key = nkey;
+	return (0);
+}
--- a/tty.c
+++ b/tty.c
@@ -409,6 +409,8 @@ tty_send_requests(struct tty *tty)
 		return;

 	if (tty->term->flags & TERM_VT100LIKE) {
+		if (~tty->flags & TTY_HAVEKKB)
+			tty_puts(tty, "\033[?u");
 		if (~tty->flags & TTY_HAVEDA)
 			tty_puts(tty, "\033[c");
 		if (~tty->flags & TTY_HAVEDA2)
@@ -507,6 +509,10 @@ tty_stop_tty(struct tty *tty)
 		tty_raw(tty, "\033[?7727l");
 	tty_raw(tty, tty_term_string(tty->term, TTYC_DSFCS));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_DSEKS));
+	if (tty->flags & TTY_KKBPUSHED) {
+		tty_raw(tty, "\033[<u");
+		tty->flags &= ~TTY_KKBPUSHED;
+	}

 	if (tty_use_margin(tty))
 		tty_raw(tty, tty_term_string(tty->term, TTYC_DSMG));
@@ -559,8 +565,12 @@ tty_update_features(struct tty *tty)

 	if (tty_use_margin(tty))
 		tty_putcode(tty, TTYC_ENMG);
-	if (options_get_number(global_options, "extended-keys"))
+	if (options_get_number(global_options, "extended-keys") == 0 ||
+	    (tty->term->flags & TERM_KITTYKEYS))
+		tty_puts(tty, tty_term_string(tty->term, TTYC_DSEKS));
+	else
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENEKS));
+	tty_update_kitty(tty, NULL);
 	if (options_get_number(global_options, "focus-events"))
 		tty_puts(tty, tty_term_string(tty->term, TTYC_ENFCS));
 	if (tty->term->flags & TERM_VT100LIKE)
--- a/window-buffer.c
+++ b/window-buffer.c
@@ -606,8 +606,7 @@ window_buffer_start_edit(struct window_buffer_modedata *data,
 	ed->name = xstrdup(paste_buffer_name(pb));
 	ed->pb = pb;

-	ed->editor = spawn_editor(c, buf, len, NULL, window_buffer_edit_close_cb,
-	    ed);
+	ed->editor = spawn_editor(c, buf, len, window_buffer_edit_close_cb, ed);
 	if (ed->editor == NULL)
 		window_buffer_finish_edit(ed);
 	else {
--- a/window-copy.c
+++ b/window-copy.c
--- a/window-customize.c
+++ b/window-customize.c
@@ -2104,8 +2104,8 @@ window_customize_start_edit(struct window_customize_modedata *data,
 		buf = "\n";
 		len = 1;
 	}
-	ed->editor = spawn_editor(c, buf, len, NULL,
-	    window_customize_edit_close_cb, ed);
+	ed->editor = spawn_editor(c, buf, len, window_customize_edit_close_cb,
+	    ed);
 	free(value);
 	if (ed->editor == NULL)
 		window_customize_finish_edit(ed);
Author	SHA1	Message	Date
Michael Grant	8c96fde851	Detection, done like sync: - ESC[?u goes to every VT100-like terminal at attach, whatever the options. - A reply turns on a new kittykeys terminal feature. Users can force it on or off with terminal-features kittykeys, including kittykeys@ to turn it off. - Changing extended-keys now takes effect immediately for attached clients (options.c). Use, per client, when extended-keys is on: Kitty for clients that have kittykeys, modifyOtherKeys for clients with extkeys, VT10x otherwise. Pane side: - Applications can request either protocol; Kitty wins if one asks for both. - Each application gets what it asked for, whichever client typed the key. - ESC[?u is answered truthfully. - The per-client gate is gone. window.c and popup.c are simply master's versions again. extended-keys always is back to its master meaning, forcing modifyOtherKeys mode 1 only. Forcing Kitty on every program would have sent bash ESC[97;5u for Ctrl-A. extended-keys-format kitty is still accepted, but now behaves the same as csi-u.	2026-09-19 07:32:57 +01:00
Michael Grant	1abf9f7023	Add a test for Kitty keyboard protocol input parsing Also note that kitty-keys-terminal.sh cannot run under the regress Makefile, which uses env -i and so removes DISPLAY and HOME, and make the Kitty test file modes match the rest of regress.	2026-09-17 06:16:11 +01:00
Michael Grant	cb80f01460	Cleanup.	2026-09-17 06:00:13 +01:00
Michael Grant	e2334c3205	Document Kitty query snapshot semantics	2026-09-15 06:14:43 +01:00
Michael Grant	9e88490a05	Simplify Kitty query completion flag	2026-09-15 06:11:25 +01:00
Michael Grant	10ea823da6	Make Kitty keyboard negotiation per client	2026-09-15 05:45:58 +01:00
Michael Grant	75cb580e36	Add Kitty keyboard protocol support	2026-09-14 14:14:28 +01:00