diff --git a/CMakeLists.txt b/CMakeLists.txt
index ddd05cf..cd28108 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -141,7 +141,7 @@ set(SOURCE_FILES
         user/apars_osc.c
         user/apars_osc.h
         user/apars_dcs.c
-        user/apars_dcs.h user/uart_buffer.c user/uart_buffer.h)
+        user/apars_dcs.h user/uart_buffer.c user/uart_buffer.h user/jstring.c user/jstring.h)
 
 include_directories(include)
 include_directories(user)
diff --git a/html_orig/js/app.js b/html_orig/js/app.js
index edd6e14..33d2510 100644
--- a/html_orig/js/app.js
+++ b/html_orig/js/app.js
@@ -770,6 +770,14 @@
       for(k in _mods) _mods[k] = event[modifierMap[k]];
   };
 
+  function isModifierPressed(mod) {
+    if (mod=='control'||mod=='ctrl') return _mods[17];
+	if (mod=='shift') return _mods[16];
+	if (mod=='meta') return _mods[91];
+	if (mod=='alt') return _mods[18];
+	return false;
+  }
+
   // handle keydown event
   function dispatch(event) {
     var key, handler, k, i, modifiersMatch, scope;
@@ -995,6 +1003,7 @@
   global.key.deleteScope = deleteScope;
   global.key.filter = filter;
   global.key.isPressed = isPressed;
+  global.key.isModifier = isModifierPressed;
   global.key.getPressedKeyCodes = getPressedKeyCodes;
   global.key.noConflict = noConflict;
   global.key.unbind = unbindKey;
@@ -1555,6 +1564,41 @@ function tr(key) { return _tr[key] || '?'+key+'?'; }
 	w.init = wifiInit;
 	w.startScanning = startScanning;
 })(window.WiFi = {});
+/** Decode two-byte number */
+function parse2B(s, i) {
+	return (s.charCodeAt(i++) - 1) + (s.charCodeAt(i) - 1) * 127;
+}
+
+/** Decode three-byte number */
+function parse3B(s, i) {
+	return (s.charCodeAt(i) - 1) + (s.charCodeAt(i+1) - 1) * 127 + (s.charCodeAt(i+2) - 1) * 127 * 127;
+}
+
+function Chr(n) {
+	return String.fromCharCode(n);
+}
+
+function encode2B(n) {
+	var lsb, msb;
+	lsb = (n % 127);
+	n = ((n - lsb) / 127);
+	lsb += 1;
+	msb = (n + 1);
+	return Chr(lsb) + Chr(msb);
+}
+
+function encode3B(n) {
+	var lsb, msb, xsb;
+	lsb = (n % 127);
+	n = (n - lsb) / 127;
+	lsb += 1;
+	msb = (n % 127);
+	n = (n - msb) / 127;
+	msb += 1;
+	xsb = (n + 1);
+	return Chr(lsb) + Chr(msb) + Chr(xsb);
+}
+
 var Screen = (function () {
 	var W = 0, H = 0; // dimensions
 	var inited = false;
@@ -1681,8 +1725,21 @@ var Screen = (function () {
 			(function() {
 				var x = i % W;
 				var y = Math.floor(i / W);
-				e.addEventListener('click', function () {
-					Input.onTap(y, x);
+				e.addEventListener('mouseenter', function (evt) {
+					Input.onMouseMove(x, y);
+				});
+				e.addEventListener('mousedown', function (evt) {
+					Input.onMouseDown(x, y, evt.button+1);
+				});
+				e.addEventListener('mouseup', function (evt) {
+					Input.onMouseUp(x, y, evt.button+1);
+				});
+				e.addEventListener('contextmenu', function (evt) {
+					evt.preventDefault();
+				});
+				e.addEventListener('mousewheel', function (evt) {
+					Input.onMouseWheel(x, y, evt.deltaY>0?1:-1);
+					return false;
 				});
 			})();
 
@@ -1734,16 +1791,6 @@ var Screen = (function () {
 		inited = true;
 	}
 
-	/** Decode two-byte number */
-	function parse2B(s, i) {
-		return (s.charCodeAt(i++) - 1) + (s.charCodeAt(i) - 1) * 127;
-	}
-
-	/** Decode three-byte number */
-	function parse3B(s, i) {
-		return (s.charCodeAt(i) - 1) + (s.charCodeAt(i+1) - 1) * 127 + (s.charCodeAt(i+2) - 1) * 127 * 127;
-	}
-
 	var SEQ_SET_COLOR_ATTR = 1;
 	var SEQ_REPEAT = 2;
 	var SEQ_SET_COLOR = 3;
@@ -1991,7 +2038,22 @@ var Conn = (function() {
 	};
 })();
 
-/** User input */
+/**
+ * User input
+ *
+ * --- Rx messages: ---
+ * S - screen content (binary encoding of the entire screen with simple compression)
+ * T - text labels - Title and buttons, \0x01-separated
+ * B - beep
+ * . - heartbeat
+ *
+ * --- Tx messages ---
+ * s - string
+ * b - action button
+ * p - mb press
+ * r - mb release
+ * m - mouse move
+ */
 var Input = (function() {
 	var opts = {
 		np_alt: false,
@@ -2000,15 +2062,11 @@ var Input = (function() {
 	};
 
 	function sendStrMsg(str) {
-		Conn.send("STR:"+str);
-	}
-
-	function sendPosMsg(y, x) {
-		Conn.send("TAP:"+y+','+x);
+		Conn.send("s"+str);
 	}
 
 	function sendBtnMsg(n) {
-		Conn.send("BTN:"+n);
+		Conn.send("b"+Chr(n));
 	}
 
 	function fa(alt, normal) {
@@ -2129,6 +2187,10 @@ var Input = (function() {
 		_bindFnKeys();
 	}
 
+	var mb1 = 0;
+	var mb2 = 0;
+	var mb3 = 0;
+
 	function init() {
 		_initKeys();
 
@@ -2138,11 +2200,30 @@ var Input = (function() {
 				sendBtnMsg(+this.dataset['n']);
 			});
 		});
+
+		window.addEventListener('mousedown', function(evt) {
+			if (evt.button == 0) mb1 = 1;
+			if (evt.button == 1) mb2 = 1;
+			if (evt.button == 2) mb3 = 1;
+		});
+
+		window.addEventListener('mouseup', function(evt) {
+			if (evt.button == 0) mb1 = 0;
+			if (evt.button == 1) mb2 = 0;
+			if (evt.button == 2) mb3 = 0;
+		});
+	}
+
+	function packModifiersForMouse() {
+		return (key.isModifier('ctrl')?1:0) |
+			(key.isModifier('shift')?2:0) |
+			(key.isModifier('alt')?4:0) |
+			(key.isModifier('meta')?8:0);
 	}
 
 	return {
 		init: init,
-		onTap: sendPosMsg,
+		// onTap: sendPosMsg,
 		sendString: sendStrMsg,
 		setAlts: function(cu, np, fn) {
 			if (opts.cu_alt != cu || opts.np_alt != np || opts.fn_alt != fn) {
@@ -2154,6 +2235,31 @@ var Input = (function() {
 				_bindFnKeys();
 			}
 		},
+		onMouseMove: function (x, y) {
+			var b = mb1 ? 1 : mb2 ? 2 : mb3 ? 3 : 0;
+			var m = packModifiersForMouse();
+			Conn.send("m" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+		},
+		onMouseDown: function (x, y, b) {
+			if (b > 3 || b < 1) return;
+			var m = packModifiersForMouse();
+			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
+		onMouseUp: function (x, y, b) {
+			if (b > 3 || b < 1) return;
+			var m = packModifiersForMouse();
+			Conn.send("r" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
+		onMouseWheel: function (x, y, dir) {
+			// -1 ... btn 4 (away from user)
+			// +1 ... btn 5 (towards user)
+			var m = packModifiersForMouse();
+			var b = (dir < 0 ? 4 : 5);
+			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
 	};
 })();
 
diff --git a/html_orig/jssrc/keymaster.js b/html_orig/jssrc/keymaster.js
index 254620b..88b9629 100644
--- a/html_orig/jssrc/keymaster.js
+++ b/html_orig/jssrc/keymaster.js
@@ -67,6 +67,14 @@
       for(k in _mods) _mods[k] = event[modifierMap[k]];
   };
 
+  function isModifierPressed(mod) {
+    if (mod=='control'||mod=='ctrl') return _mods[17];
+	if (mod=='shift') return _mods[16];
+	if (mod=='meta') return _mods[91];
+	if (mod=='alt') return _mods[18];
+	return false;
+  }
+
   // handle keydown event
   function dispatch(event) {
     var key, handler, k, i, modifiersMatch, scope;
@@ -292,6 +300,7 @@
   global.key.deleteScope = deleteScope;
   global.key.filter = filter;
   global.key.isPressed = isPressed;
+  global.key.isModifier = isModifierPressed;
   global.key.getPressedKeyCodes = getPressedKeyCodes;
   global.key.noConflict = noConflict;
   global.key.unbind = unbindKey;
diff --git a/html_orig/jssrc/term.js b/html_orig/jssrc/term.js
index 313b8e1..4686cee 100644
--- a/html_orig/jssrc/term.js
+++ b/html_orig/jssrc/term.js
@@ -1,3 +1,38 @@
+/** Decode two-byte number */
+function parse2B(s, i) {
+	return (s.charCodeAt(i++) - 1) + (s.charCodeAt(i) - 1) * 127;
+}
+
+/** Decode three-byte number */
+function parse3B(s, i) {
+	return (s.charCodeAt(i) - 1) + (s.charCodeAt(i+1) - 1) * 127 + (s.charCodeAt(i+2) - 1) * 127 * 127;
+}
+
+function Chr(n) {
+	return String.fromCharCode(n);
+}
+
+function encode2B(n) {
+	var lsb, msb;
+	lsb = (n % 127);
+	n = ((n - lsb) / 127);
+	lsb += 1;
+	msb = (n + 1);
+	return Chr(lsb) + Chr(msb);
+}
+
+function encode3B(n) {
+	var lsb, msb, xsb;
+	lsb = (n % 127);
+	n = (n - lsb) / 127;
+	lsb += 1;
+	msb = (n % 127);
+	n = (n - msb) / 127;
+	msb += 1;
+	xsb = (n + 1);
+	return Chr(lsb) + Chr(msb) + Chr(xsb);
+}
+
 var Screen = (function () {
 	var W = 0, H = 0; // dimensions
 	var inited = false;
@@ -124,8 +159,21 @@ var Screen = (function () {
 			(function() {
 				var x = i % W;
 				var y = Math.floor(i / W);
-				e.addEventListener('click', function () {
-					Input.onTap(y, x);
+				e.addEventListener('mouseenter', function (evt) {
+					Input.onMouseMove(x, y);
+				});
+				e.addEventListener('mousedown', function (evt) {
+					Input.onMouseDown(x, y, evt.button+1);
+				});
+				e.addEventListener('mouseup', function (evt) {
+					Input.onMouseUp(x, y, evt.button+1);
+				});
+				e.addEventListener('contextmenu', function (evt) {
+					evt.preventDefault();
+				});
+				e.addEventListener('mousewheel', function (evt) {
+					Input.onMouseWheel(x, y, evt.deltaY>0?1:-1);
+					return false;
 				});
 			})();
 
@@ -177,16 +225,6 @@ var Screen = (function () {
 		inited = true;
 	}
 
-	/** Decode two-byte number */
-	function parse2B(s, i) {
-		return (s.charCodeAt(i++) - 1) + (s.charCodeAt(i) - 1) * 127;
-	}
-
-	/** Decode three-byte number */
-	function parse3B(s, i) {
-		return (s.charCodeAt(i) - 1) + (s.charCodeAt(i+1) - 1) * 127 + (s.charCodeAt(i+2) - 1) * 127 * 127;
-	}
-
 	var SEQ_SET_COLOR_ATTR = 1;
 	var SEQ_REPEAT = 2;
 	var SEQ_SET_COLOR = 3;
@@ -434,7 +472,22 @@ var Conn = (function() {
 	};
 })();
 
-/** User input */
+/**
+ * User input
+ *
+ * --- Rx messages: ---
+ * S - screen content (binary encoding of the entire screen with simple compression)
+ * T - text labels - Title and buttons, \0x01-separated
+ * B - beep
+ * . - heartbeat
+ *
+ * --- Tx messages ---
+ * s - string
+ * b - action button
+ * p - mb press
+ * r - mb release
+ * m - mouse move
+ */
 var Input = (function() {
 	var opts = {
 		np_alt: false,
@@ -443,15 +496,11 @@ var Input = (function() {
 	};
 
 	function sendStrMsg(str) {
-		Conn.send("STR:"+str);
-	}
-
-	function sendPosMsg(y, x) {
-		Conn.send("TAP:"+y+','+x);
+		Conn.send("s"+str);
 	}
 
 	function sendBtnMsg(n) {
-		Conn.send("BTN:"+n);
+		Conn.send("b"+Chr(n));
 	}
 
 	function fa(alt, normal) {
@@ -572,6 +621,10 @@ var Input = (function() {
 		_bindFnKeys();
 	}
 
+	var mb1 = 0;
+	var mb2 = 0;
+	var mb3 = 0;
+
 	function init() {
 		_initKeys();
 
@@ -581,11 +634,30 @@ var Input = (function() {
 				sendBtnMsg(+this.dataset['n']);
 			});
 		});
+
+		window.addEventListener('mousedown', function(evt) {
+			if (evt.button == 0) mb1 = 1;
+			if (evt.button == 1) mb2 = 1;
+			if (evt.button == 2) mb3 = 1;
+		});
+
+		window.addEventListener('mouseup', function(evt) {
+			if (evt.button == 0) mb1 = 0;
+			if (evt.button == 1) mb2 = 0;
+			if (evt.button == 2) mb3 = 0;
+		});
+	}
+
+	function packModifiersForMouse() {
+		return (key.isModifier('ctrl')?1:0) |
+			(key.isModifier('shift')?2:0) |
+			(key.isModifier('alt')?4:0) |
+			(key.isModifier('meta')?8:0);
 	}
 
 	return {
 		init: init,
-		onTap: sendPosMsg,
+		// onTap: sendPosMsg,
 		sendString: sendStrMsg,
 		setAlts: function(cu, np, fn) {
 			if (opts.cu_alt != cu || opts.np_alt != np || opts.fn_alt != fn) {
@@ -597,6 +669,31 @@ var Input = (function() {
 				_bindFnKeys();
 			}
 		},
+		onMouseMove: function (x, y) {
+			var b = mb1 ? 1 : mb2 ? 2 : mb3 ? 3 : 0;
+			var m = packModifiersForMouse();
+			Conn.send("m" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+		},
+		onMouseDown: function (x, y, b) {
+			if (b > 3 || b < 1) return;
+			var m = packModifiersForMouse();
+			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
+		onMouseUp: function (x, y, b) {
+			if (b > 3 || b < 1) return;
+			var m = packModifiersForMouse();
+			Conn.send("r" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
+		onMouseWheel: function (x, y, dir) {
+			// -1 ... btn 4 (away from user)
+			// +1 ... btn 5 (towards user)
+			var m = packModifiersForMouse();
+			var b = (dir < 0 ? 4 : 5);
+			Conn.send("p" + encode2B(y) + encode2B(x) + encode2B(b) + encode2B(m));
+			console.log("B ",b," M ",m);
+		},
 	};
 })();
 
diff --git a/user/apars_csi.c b/user/apars_csi.c
index c1ce4f5..6179996 100644
--- a/user/apars_csi.c
+++ b/user/apars_csi.c
@@ -451,16 +451,26 @@ static void ICACHE_FLASH_ATTR do_csi_privattr(CSI_Data *opts)
 				// - discard repeated keypress events between keydown and keyup.
 				ansi_noimpl("Auto-repeat toggle");
 			}
-			else if (n == 9 || (n >= 1000 && n <= 1006)) {
-				// TODO mouse
-				// 1000 - C11 mouse - Send Mouse X & Y on button press and release.
-				// 1001 - Hilite mouse tracking
+			else if (n == 9 || (n >= 1000 && n <= 1006) || n == 1015) {
+				// 9 - X10 tracking
+				// 1000 - X11 mouse - Send Mouse X & Y on button press and release.
+				// 1001 - Hilite mouse tracking - not impl
 				// 1002 - Cell Motion Mouse Tracking
 				// 1003 - All Motion Mouse Tracking
 				// 1004 - Send FocusIn/FocusOut events
-				// 1005 - Enable UTF-8 Mouse Mode
+				// 1005 - Enable UTF-8 Mouse Mode - we implement this as an alias to X10 mode
 				// 1006 - SGR mouse mode
-				ansi_noimpl("Mouse tracking");
+
+				if (n == 9) mouse_tracking.mode = yn ? MTM_X10 : MTM_NONE;
+				else if (n == 1000) mouse_tracking.mode = yn ? MTM_NORMAL : MTM_NONE;
+				else if (n == 1002) mouse_tracking.mode = yn ? MTM_BUTTON_MOTION : MTM_NONE;
+				else if (n == 1003) mouse_tracking.mode = yn ? MTM_ANY_MOTION : MTM_NONE;
+				else if (n == 1004) mouse_tracking.focus_tracking = yn;
+				else if (n == 1005) mouse_tracking.encoding = yn ? MTE_UTF8 : MTE_SIMPLE;
+				else if (n == 1006) mouse_tracking.encoding = yn ? MTE_SGR : MTE_SIMPLE;
+				else if (n == 1015) mouse_tracking.encoding = yn ? MTE_URXVT : MTE_SIMPLE;
+
+				dbg("Mouse opt %d yesno %d", n, yn);
 			}
 			else if (n == 12) {
 				// TODO Cursor blink on/off
diff --git a/user/apars_osc.c b/user/apars_osc.c
index 18f9855..fc2b27b 100644
--- a/user/apars_osc.c
+++ b/user/apars_osc.c
@@ -15,18 +15,6 @@
 #include "screen.h"
 #include "ansi_parser.h"
 
-/**
- * Helper function to set terminal button label
- * @param num - button number 1-5
- * @param str - button text
- */
-static void ICACHE_FLASH_ATTR
-set_button_text(int num, const char *str)
-{
-	strncpy(termconf_scratch.btn[num-1], str, TERM_BTN_LEN);
-	screen_notifyChange(CHANGE_LABELS);
-}
-
 /**
  * Helper function to parse incoming OSC (Operating System Control)
  * @param buffer - the OSC body (after OSC and before ST)
@@ -52,7 +40,7 @@ apars_handle_osc(const char *buffer)
 			screen_set_title(buffer);
 		}
 		else if (n >= 81 && n <= 85) { // numbers chosen to not collide with any xterm supported codes
-			set_button_text(n - 80, buffer);
+			screen_set_button_text(n - 80, buffer);
 		}
 		else {
 			ansi_noimpl("OSC %d ; %s ST", n, buffer);
diff --git a/user/cgi_sockets.c b/user/cgi_sockets.c
index c3a164a..f65bb6e 100644
--- a/user/cgi_sockets.c
+++ b/user/cgi_sockets.c
@@ -7,6 +7,7 @@
 #include "screen.h"
 #include "uart_buffer.h"
 #include "ansi_parser.h"
+#include "jstring.h"
 
 #define LOOPBACK 0
 
@@ -118,75 +119,127 @@ void ICACHE_FLASH_ATTR screen_notifyChange(ScreenNotifyChangeTopic topic)
 	}
 }
 
+void ICACHE_FLASH_ATTR sendMouseAction(char evt, int y, int x, int button, u8 mods)
+{
+	// one-based
+	x++;
+	y++;
+
+	bool ctrl = (mods & 1) > 0;
+	bool shift = (mods & 2) > 0;
+	bool alt = (mods & 4) > 0;
+	bool meta = (mods & 8) > 0;
+	enum MTM mtm = mouse_tracking.mode;
+	enum MTE mte = mouse_tracking.encoding;
+
+	// No message on release in X10 mode
+	if (mtm == MTM_X10 && (button == 0 || evt == 'r')) {
+		return;
+	}
+
+	if (evt == 'm' && mtm != MTM_BUTTON_MOTION && mtm != MTM_ANY_MOTION) {
+		return;
+	}
+
+	if (evt == 'm' && mtm == MTM_BUTTON_MOTION && button == 0) {
+		return;
+	}
+
+	int eventcode = 0;
+
+	if (mtm == MTM_X10) {
+		eventcode = button-1;
+	}
+	else {
+		if (button == 0 || (evt == 'r' && mte != MTE_SGR)) eventcode = 3; // release
+		else if (button == 1) eventcode = 0;
+		else if (button == 2) eventcode = 1;
+		else if (button == 3) eventcode = 2;
+		else if (button == 4) eventcode = 64;
+		else if (button == 5) eventcode = 65;
+
+		if (shift) eventcode |= 4;
+		if (alt || meta) eventcode |= 8;
+		if (ctrl) eventcode |= 16;
+
+		if (mtm == MTM_BUTTON_MOTION || mtm == MTM_ANY_MOTION) {
+			if (evt == 'm') {
+				eventcode |= 32;
+			}
+		}
+	}
+
+	// Encode
+	char buf[20];
+	buf[0] = 0;
+	if (mte == MTE_SIMPLE || mte == MTE_UTF8) {
+		// strictly, for UTF8 this will break if any coord is over 127,
+		// but that is unlikely due to screen size limitations in ESPTerm
+		sprintf(buf, "\x1b[M%c%c%c", (u8)(32+eventcode), (u8)(32+x), (u8)(32+y));
+	}
+	else if (mte == MTE_SGR) {
+		sprintf(buf, "\x1b[<%d;%d;%d%c", eventcode, x, y, evt == 'p' ? 'M' : 'm');
+	}
+	else if (mte == MTE_URXVT) {
+		sprintf(buf, "\x1b[%d;%d;%dM", (u8)(32+eventcode), (u8)(32+x), (u8)(32+y));
+	}
+
+	UART_SendAsync(buf, -1);
+}
+
 /** Socket received a message */
 void ICACHE_FLASH_ATTR updateSockRx(Websock *ws, char *data, int len, int flags)
 {
-	char buf[20];
 	// Add terminator if missing (seems to randomly happen)
 	data[len] = 0;
 
-	// TODO re-implement those, use single byte markers and B2 encoding
-
 	ws_dbg("Sock RX str: %s, len %d", data, len);
 
-	if (strstarts(data, "STR:")) {
+	int y, x, m, b;
+	u8 btnNum;
+
+	char c = data[0];
+	switch (c) {
+		case 's':
 		// pass string verbatim
 #if LOOPBACK
 		for(int i=4;i<strlen(data); i++) {
 			ansi_parser(data[i]);
 		}
 #else
-		UART_SendAsync(data+4, -1);
+			UART_SendAsync(data+1, -1);
 #endif
-	}
-	else if (strstarts(data, "BTN:")) {
-		// send button as low ASCII value 1-9
-		u8 btnNum = (u8) (data[4] - '0');
-		if (btnNum > 0 && btnNum < 10) {
-			UART_SendAsync((const char *) &btnNum, 1);
-		}
-	}
-	else if (strstarts(data, "TAP:")) {
-		// this comes in as 0-based
-
-		int y=0, x=0;
-
-		char *pc=data+4;
-		char c;
-		int phase=0;
-
-		while((c=*pc++) != '\0') {
-			if (c==','||c==';') {
-				phase++;
-			}
-			else if (c>='0' && c<='9') {
-				if (phase==0) {
-					y=y*10+(c-'0');
-				} else {
-					x=x*10+(c-'0');
-				}
+			break;
+		case 'b':
+			// action button press
+			btnNum = (u8) (data[1]);
+			if (btnNum > 0 && btnNum < 10) {
+				UART_SendAsync((const char *) &btnNum, 1); // TODO this is where we use user-configured codes
 			}
-		}
-
-		if (!screen_isCoordValid(y, x)) {
-			ws_warn("Mouse input at invalid coordinates");
-			return;
-		}
-
-		ws_dbg("Screen clicked at row %d, col %d", y+1, x+1);
-
-		// Send as 1-based to user
-		sprintf(buf, "\033[%d;%dM", y+1, x+1);
-		UART_SendAsync(buf, -1);
-	}
-	else {
-		ws_warn("Bad command.");
+			break;
+		case 'm':
+		case 'p':
+		case 'r':
+			if (mouse_tracking.mode == MTM_NONE) break; // no need to parse, not enabled
+
+			// mouse move
+			y = parse2B(data+1); // row, 0-based
+			x = parse2B(data+3); // column, 0-based
+			b = parse2B(data+5); // mouse button, 0 = none, 1-5 = button number
+			m = parse2B(data+7); // modifier keys held
+
+			sendMouseAction(c,y,x,b,m);
+			break;
+		default:
+			ws_warn("Bad command.");
 	}
 }
 
 void ICACHE_FLASH_ATTR heartbeatTimCb(void *unused)
 {
 	if (notify_available) {
+		// Heartbeat packet - indicate we're still connected
+		// JS reloads the page if heartbeat is lost for a couple seconds
 		cgiWebsockBroadcast(URL_WS_UPDATE, ".", 1, 0);
 	}
 }
diff --git a/user/jstring.c b/user/jstring.c
new file mode 100644
index 0000000..f3057dc
--- /dev/null
+++ b/user/jstring.c
@@ -0,0 +1,41 @@
+//
+// Created by MightyPork on 2017/09/04.
+//
+
+#include "jstring.h"
+
+void ICACHE_FLASH_ATTR
+encode2B(u16 number, WordB2 *stru)
+{
+	stru->lsb = (u8) (number % 127);
+	number = (u16) ((number - stru->lsb) / 127);
+	stru->lsb += 1;
+
+	stru->msb = (u8) (number + 1);
+}
+
+void ICACHE_FLASH_ATTR
+encode3B(u32 number, WordB3 *stru)
+{
+	stru->lsb = (u8) (number % 127);
+	number = (number - stru->lsb) / 127;
+	stru->lsb += 1;
+
+	stru->msb = (u8) (number % 127);
+	number = (number - stru->msb) / 127;
+	stru->msb += 1;
+
+	stru->xsb = (u8) (number + 1);
+}
+
+u16 ICACHE_FLASH_ATTR
+parse2B(const char *str)
+{
+	return (u16) ((str[0] - 1) + (str[1] - 1) * 127);
+}
+
+u32 ICACHE_FLASH_ATTR
+parse3B(const char *str)
+{
+	return (u32) ((str[0] - 1) + (str[1] - 1) * 127 + (str[2] - 1) * 127 * 127);
+}
diff --git a/user/jstring.h b/user/jstring.h
new file mode 100644
index 0000000..8d99286
--- /dev/null
+++ b/user/jstring.h
@@ -0,0 +1,29 @@
+//
+// Created by MightyPork on 2017/09/04.
+//
+
+#ifndef ESPTERM_JSTRING_H
+#define ESPTERM_JSTRING_H
+
+#include <esp8266.h>
+
+typedef struct {
+	u8 lsb;
+	u8 msb;
+} WordB2;
+
+typedef struct {
+	u8 lsb;
+	u8 msb;
+	u8 xsb;
+} WordB3;
+
+void encode2B(u16 number, WordB2 *stru);
+
+void encode3B(u32 number, WordB3 *stru);
+
+u16 parse2B(const char *str);
+
+u32 parse3B(const char *str);
+
+#endif //ESPTERM_JSTRING_H
diff --git a/user/screen.c b/user/screen.c
index 5c29a53..7ea042f 100644
--- a/user/screen.c
+++ b/user/screen.c
@@ -5,10 +5,13 @@
 #include "sgr.h"
 #include "ascii.h"
 #include "apars_logging.h"
+#include "jstring.h"
 
 TerminalConfigBundle * const termconf = &persist.current.termconf;
 TerminalConfigBundle termconf_scratch;
 
+MouseTrackingConfig mouse_tracking;
+
 // forward declare
 static void utf8_remap(char* out, char g, char charset);
 
@@ -255,6 +258,10 @@ screen_reset(void)
 	scr.vm0 = 0;
 	scr.vm1 = H-1;
 
+	mouse_tracking.encoding = MTE_SIMPLE;
+	mouse_tracking.focus_tracking = false;
+	mouse_tracking.mode = MTM_NONE;
+
 	// size is left unchanged
 	screen_clear(CLEAR_ALL);
 
@@ -627,6 +634,18 @@ screen_set_title(const char *title)
 	screen_notifyChange(CHANGE_LABELS);
 }
 
+/**
+ * Helper function to set terminal button label
+ * @param num - button number 1-5
+ * @param str - button text
+ */
+void ICACHE_FLASH_ATTR
+screen_set_button_text(int num, const char *text)
+{
+	strncpy(termconf_scratch.btn[num-1], text, TERM_BTN_LEN);
+	screen_notifyChange(CHANGE_LABELS);
+}
+
 /**
  * Shift screen upwards
  */
@@ -1307,30 +1326,6 @@ struct ScreenSerializeState {
 	int index;
 };
 
-void ICACHE_FLASH_ATTR
-encode2B(u16 number, WordB2 *stru)
-{
-	stru->lsb = (u8) (number % 127);
-	number = (u16) ((number - stru->lsb) / 127);
-	stru->lsb += 1;
-
-	stru->msb = (u8) (number + 1);
-}
-
-void ICACHE_FLASH_ATTR
-encode3B(u32 number, WordB3 *stru)
-{
-	stru->lsb = (u8) (number % 127);
-	number = (number - stru->lsb) / 127;
-	stru->lsb += 1;
-
-	stru->msb = (u8) (number % 127);
-	number = (number - stru->msb) / 127;
-	stru->msb += 1;
-
-	stru->xsb = (u8) (number + 1);
-}
-
 /**
  * buffer should be at least 64+5*10+6 long (title + buttons + 6), ie. 120
  * @param buffer
diff --git a/user/screen.h b/user/screen.h
index 66b97fe..3c1ea3b 100644
--- a/user/screen.h
+++ b/user/screen.h
@@ -80,6 +80,29 @@ extern TerminalConfigBundle * const termconf;
  */
 extern TerminalConfigBundle termconf_scratch;
 
+enum MTM {
+	MTM_NONE = 0,
+	MTM_X10 = 1,
+	MTM_NORMAL = 2,
+	MTM_BUTTON_MOTION = 3,
+	MTM_ANY_MOTION = 4,
+};
+
+enum MTE {
+	MTE_SIMPLE = 0,
+	MTE_UTF8 = 1,
+	MTE_SGR = 2,
+	MTE_URXVT = 3,
+};
+
+typedef struct {
+	enum MTM mode;
+	bool focus_tracking;
+	enum MTE encoding;
+} MouseTrackingConfig;
+
+extern MouseTrackingConfig mouse_tracking;
+
 /** Restore default settings to termconf. Does not apply or copy to scratch. */
 void terminal_restore_defaults(void);
 /** Apply settings, redraw (clears the screen) */
@@ -97,17 +120,6 @@ void screen_set_button_text(int num, const char *text);
 
 // --- Encoding ---
 
-typedef struct {
-	u8 lsb;
-	u8 msb;
-} WordB2;
-
-typedef struct {
-	u8 lsb;
-	u8 msb;
-	u8 xsb;
-} WordB3;
-
 typedef enum {
 	CS_USASCII = 'B',
 	CS_UKASCII = 'A',
@@ -115,9 +127,6 @@ typedef enum {
 	CS_DOS_437 = '1',
 } CHARSET;
 
-/** Encode number to two nice ASCII bytes */
-void encode2B(u16 number, WordB2 *stru);
-
 httpd_cgi_state screenSerializeToBuffer(char *buffer, size_t buf_len, void **data);
 
 void screenSerializeLabelsToBuffer(char *buffer, size_t buf_len);