diff --git a/gen/apc_parsers.py b/gen/apc_parsers.py
index 408c8b4aa2..0d007f2fea 100755
--- a/gen/apc_parsers.py
+++ b/gen/apc_parsers.py
@@ -69,7 +69,7 @@ def parse_number(keymap: KeymapType) -> tuple[str, str]:
     return '; '.join(int_keys), '; '.join(uint_keys)
 
 
-def cmd_for_report(report_name: str, keymap: KeymapType, type_map: dict[str, Any], payload_allowed: bool) -> str:
+def cmd_for_report(report_name: str, keymap: KeymapType, type_map: dict[str, Any], payload_allowed: bool, payload_is_base64: bool) -> str:
     def group(atype: str, conv: str) -> tuple[str, str]:
         flag_fmt, flag_attrs = [], []
         cv = {'flag': 'c', 'int': 'i', 'uint': 'I'}[atype]
@@ -85,7 +85,7 @@ def group(atype: str, conv: str) -> tuple[str, str]:
 
     fmt = f'{flag_fmt} {uint_fmt} {int_fmt}'
     if payload_allowed:
-        ans = [f'REPORT_VA_COMMAND("K s {{{fmt} sI}} y#", self->window_id, "{report_name}",\n']
+        ans = [f'REPORT_VA_COMMAND("K s {{{fmt} ss#}}", self->window_id, "{report_name}",\n']
     else:
         ans = [f'REPORT_VA_COMMAND("K s {{{fmt}}}", self->window_id, "{report_name}",\n']
     if flag_attrs:
@@ -95,7 +95,10 @@ def group(atype: str, conv: str) -> tuple[str, str]:
     if int_attrs:
         ans.append(f'{int_attrs},\n')
     if payload_allowed:
-        ans.append('"payload_sz", g.payload_sz, parser_buf, g.payload_sz')
+        if payload_is_base64:
+            ans.append('"", (char*)parser_buf, g.payload_sz')
+        else:
+            ans.append('"", (char*)parser_buf + payload_start, g.payload_sz')
     ans.append(');')
     return '\n'.join(ans)
 
@@ -117,7 +120,7 @@ def generate(
     handle_key = parse_key(keymap)
     flag_keys = parse_flag(keymap, type_map, command_class)
     int_keys, uint_keys = parse_number(keymap)
-    report_cmd = cmd_for_report(report_name, keymap, type_map, payload_allowed)
+    report_cmd = cmd_for_report(report_name, keymap, type_map, payload_allowed, payload_is_base64)
     extra_init = ''
     if payload_allowed:
         payload_after_value = "case ';': state = PAYLOAD; break;"
diff --git a/kitty/boss.py b/kitty/boss.py
index 217d394bb2..14d8e53a3f 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -238,8 +238,13 @@ def __call__(self, window_id: int, what: str, *a: Any) -> None:
             if self.draw_dump_buf:
                 safe_print('draw', ''.join(self.draw_dump_buf))
                 self.draw_dump_buf = []
-            a = tuple(str(x, 'utf-8', 'replace') if isinstance(x, memoryview) else x for x in a)
-            safe_print(what, *a)
+            def fmt(x: Any) -> Any:
+                if isinstance(x, (bytes, memoryview)):
+                    return str(x, 'utf-8', 'replace')
+                if isinstance(x, dict):
+                    return json.dumps(x)
+                return x
+            safe_print(what, *map(fmt, a))
 # }}}
 
 
diff --git a/kitty/client.py b/kitty/client.py
index 541b7ac55a..4faf920470 100644
--- a/kitty/client.py
+++ b/kitty/client.py
@@ -7,10 +7,13 @@
 # kitty --replay-commands file.txt
 # will replay the commands and pause at the end waiting for user to press enter
 
+import json
 import sys
 from contextlib import suppress
 from typing import Any
 
+from .fast_data_types import TEXT_SIZE_CODE
+
 CSI = '\x1b['
 OSC = '\x1b]'
 
@@ -74,8 +77,8 @@ def screen_designate_charset(which: int, to: int) -> None:
     write(f'\x1b{w}{t}')
 
 
-def select_graphic_rendition(*a: int) -> None:
-    write(f'{CSI}{";".join(map(str, a))}m')
+def select_graphic_rendition(payload: str) -> None:
+    write(f'{CSI}{payload}m')
 
 
 def deccara(*a: int) -> None:
@@ -267,11 +270,26 @@ def clipboard_control(payload: str) -> None:
     write(f'{OSC}{payload}\x07')
 
 
+def multicell_command(payload: str) -> None:
+    c = json.loads(payload)
+    text = c.pop('', '')
+    m = ''
+    if (w := c.get('width')) is not None and w > 0:
+        m += f'w={w}:'
+    if (s := c.get('scale')) is not None and s > 1:
+        m += f's={s}:'
+    if (n := c.get('subscale_n')) is not None and n > 0:
+        m += f'n={n}:'
+    if (d := c.get('subscale_d')) is not None and d > 0:
+        m += f'd={d}:'
+    write(f'{OSC}{TEXT_SIZE_CODE};{m.rstrip(":")};{text}\a')
+
+
 def replay(raw: str) -> None:
-    specials = {
-        'draw', 'set_title', 'set_icon', 'set_dynamic_color', 'set_color_table_color',
-        'process_cwd_notification', 'clipboard_control', 'shell_prompt_marking'
-    }
+    specials = frozenset({
+        'draw', 'set_title', 'set_icon', 'set_dynamic_color', 'set_color_table_color', 'select_graphic_rendition',
+        'process_cwd_notification', 'clipboard_control', 'shell_prompt_marking', 'multicell_command',
+    })
     for line in raw.splitlines():
         if line.strip() and not line.startswith('#'):
             cmd, rest = line.partition(' ')[::2]
diff --git a/kitty/fast_data_types.pyi b/kitty/fast_data_types.pyi
index 8401d16a50..aa101357e8 100644
--- a/kitty/fast_data_types.pyi
+++ b/kitty/fast_data_types.pyi
@@ -308,6 +308,7 @@ WINDOW_NORMAL: int = 0
 WINDOW_FULLSCREEN: int
 WINDOW_MAXIMIZED: int
 WINDOW_MINIMIZED: int
+TEXT_SIZE_CODE: int
 # }}}
 
 
diff --git a/kitty/line.h b/kitty/line.h
index d99f392509..60c135e568 100644
--- a/kitty/line.h
+++ b/kitty/line.h
@@ -11,11 +11,9 @@
 
 // TODO: Test setting of ch_and_idx to make sure the right ch_is_idx bit is set
 // TODO: Test handling of calt ligatures with scale see is_group_calt_ligature()
-// TODO: Font Rendering of scale > 1 and width > 1
 // TODO: Handle selection with multicell
 // TODO: URL detection with multicell
 // TODO: Cursor rendering over multicell
-// TODO: Handle replay of dumped graphics_command and multicell_command
 // TODO: Handle rewrap and restitch of multiline chars
 // TODO: Handle rewrap when a character is too wide/tall to fit on resized screen
 // TODO: Implement baseline align for box drawing
diff --git a/kitty/parse-graphics-command.h b/kitty/parse-graphics-command.h
index 622dcb3c40..092740f807 100644
--- a/kitty/parse-graphics-command.h
+++ b/kitty/parse-graphics-command.h
@@ -359,7 +359,7 @@ static inline void parse_graphics_code(PS *self, uint8_t *parser_buf,
 
   REPORT_VA_COMMAND(
       "K s {sc sc sc sc sI sI sI sI sI sI sI sI sI sI sI sI sI sI sI sI sI sI "
-      "sI sI sI sI si si si sI} y#",
+      "sI sI sI sI si si si ss#}",
       self->window_id, "graphics_command",
 
       "action", g.action, "delete_action", g.delete_action, "transmission_type",
@@ -384,7 +384,7 @@ static inline void parse_graphics_code(PS *self, uint8_t *parser_buf,
       (int)g.offset_from_parent_x, "offset_from_parent_y",
       (int)g.offset_from_parent_y,
 
-      "payload_sz", g.payload_sz, parser_buf, g.payload_sz);
+      "", (char *)parser_buf, g.payload_sz);
 
   screen_handle_graphics_command(self->screen, &g, parser_buf);
 }
diff --git a/kitty/parse-multicell-command.h b/kitty/parse-multicell-command.h
index b9f9ef6621..1cd8876573 100644
--- a/kitty/parse-multicell-command.h
+++ b/kitty/parse-multicell-command.h
@@ -183,14 +183,14 @@ static inline void parse_multicell_code(PS *self, uint8_t *parser_buf,
   }
 
   REPORT_VA_COMMAND(
-      "K s { sI sI sI sI sI  sI} y#", self->window_id, "multicell_command",
+      "K s { sI sI sI sI sI  ss#}", self->window_id, "multicell_command",
 
       "width", (unsigned int)g.width, "scale", (unsigned int)g.scale,
       "subscale_n", (unsigned int)g.subscale_n, "subscale_d",
       (unsigned int)g.subscale_d, "vertical_align",
       (unsigned int)g.vertical_align,
 
-      "payload_sz", g.payload_sz, parser_buf, g.payload_sz);
+      "", (char *)parser_buf + payload_start, g.payload_sz);
 
   screen_handle_multicell_command(self->screen, &g, parser_buf + payload_start);
 }
diff --git a/kitty/vt-parser.c b/kitty/vt-parser.c
index a1d06e78c8..5cac099e08 100644
--- a/kitty/vt-parser.c
+++ b/kitty/vt-parser.c
@@ -61,8 +61,8 @@ static void
 _report_params(PyObject *dump_callback, id_type window_id, const char *name, int *params, unsigned int count, bool is_group, Region *r) {
     static char buf[MAX_CSI_PARAMS*3] = {0};
     unsigned int i, p=0;
-    if (r) p += snprintf(buf + p, sizeof(buf) - 2, "%u %u %u %u ", r->top, r->left, r->bottom, r->right);
-    const char *fmt = is_group ? "%i:" : "%i ";
+    if (r) p += snprintf(buf + p, sizeof(buf) - 2, "%u;%u;%u;%u;", r->top, r->left, r->bottom, r->right);
+    const char *fmt = is_group ? "%i:" : "%i;";
     for(i = 0; i < count && p < arraysz(buf)-20; i++) {
         int n = snprintf(buf + p, arraysz(buf) - p, fmt, params[i]);
         if (n < 0) break;
diff --git a/kitty_tests/parser.py b/kitty_tests/parser.py
index aec8c9086d..38d994f51f 100644
--- a/kitty_tests/parser.py
+++ b/kitty_tests/parser.py
@@ -385,7 +385,7 @@ def test_csi_codes(self):
         def sgr(*params):
             return (('select_graphic_rendition', f'{x}') for x in params)
 
-        pb('\033[1;2;3;4;7;9;34;44m', *sgr('1 2 3 4 7 9 34 44'))
+        pb('\033[1;2;3;4;7;9;34;44m', *sgr('1;2;3;4;7;9;34;44'))
         for attr in 'bold italic reverse strikethrough dim'.split():
             self.assertTrue(getattr(s.cursor, attr), attr)
         self.ae(s.cursor.decoration, 1)
@@ -397,10 +397,10 @@ def sgr(*params):
         pb('\033[38;2;1;2;3;48;2;7;8;9m', ('select_graphic_rendition', '38:2:1:2:3'), ('select_graphic_rendition', '48:2:7:8:9'))
         self.ae(s.cursor.fg, 1 << 24 | 2 << 16 | 3 << 8 | 2)
         self.ae(s.cursor.bg, 7 << 24 | 8 << 16 | 9 << 8 | 2)
-        pb('\033[0;2m', *sgr('0 2'))
-        pb('\033[;2m', *sgr('0 2'))
+        pb('\033[0;2m', *sgr('0;2'))
+        pb('\033[;2m', *sgr('0;2'))
         pb('\033[m', *sgr('0'))
-        pb('\033[1;;2m', *sgr('1 0 2'))
+        pb('\033[1;;2m', *sgr('1;0;2'))
         pb('\033[38;5;1m', ('select_graphic_rendition', '38:5:1'))
         pb('\033[58;2;1;2;3m', ('select_graphic_rendition', '58:2:1:2:3'))
         pb('\033[38;2;1;2;3m', ('select_graphic_rendition', '38:2:1:2:3'))
@@ -408,7 +408,7 @@ def sgr(*params):
         pb('\033[38:2:1:2:3;48:5:9;58;5;7m', (
             'select_graphic_rendition', '38:2:1:2:3'), ('select_graphic_rendition', '48:5:9'), ('select_graphic_rendition', '58:5:7'))
         s.reset()
-        pb('\033[1;2;3;4:5;7;9;34;44m', *sgr('1 2 3', '4:5', '7 9 34 44'))
+        pb('\033[1;2;3;4:5;7;9;34;44m', *sgr('1;2;3', '4:5', '7;9;34;44'))
         for attr in 'bold italic reverse strikethrough dim'.split():
             self.assertTrue(getattr(s.cursor, attr), attr)
         self.ae(s.cursor.decoration, 5)
@@ -584,9 +584,9 @@ def c(**k):
                       ' parent_id parent_placement_id offset_from_parent_x offset_from_parent_y'
             ).split():
                 k.setdefault(f, 0)
-            p = k.pop('payload', '').encode('utf-8')
-            k['payload_sz'] = len(p)
-            return ('graphics_command', k, p)
+            p = k.pop('payload', '')
+            k[''] = p
+            return ('graphics_command', k)
 
         def t(cmd, **kw):
             pb('\033_G{};{}\033\\'.format(cmd, enc(kw.get('payload', ''))), c(**kw))
@@ -601,8 +601,8 @@ def e(cmd, err):
         t('i=3,p=4', id=3, placement_id=4)
         e('i=%d' % (uint32_max + 1), 'Malformed GraphicsCommand control block, number is too large')
         pb('\033_Gi=12\033\\', c(id=12))
-        t('a=t,t=d,s=100,z=-9', payload='X', action='t', transmission_type='d', data_width=100, z_index=-9, payload_sz=1)
-        t('a=t,t=d,s=100,z=9', payload='payload', action='t', transmission_type='d', data_width=100, z_index=9, payload_sz=7)
+        t('a=t,t=d,s=100,z=-9', payload='X', action='t', transmission_type='d', data_width=100, z_index=-9)
+        t('a=t,t=d,s=100,z=9', payload='payload', action='t', transmission_type='d', data_width=100, z_index=9)
         t('a=t,t=d,s=100,z=9,q=2', action='t', transmission_type='d', data_width=100, z_index=9, quiet=2)
         e(',s=1', 'Malformed GraphicsCommand control block, invalid key character: 0x2c')
         e('W=1', 'Malformed GraphicsCommand control block, invalid key character: 0x57')
@@ -616,9 +616,9 @@ def e(cmd, err):
     def test_deccara(self):
         s = self.create_screen()
         pb = partial(self.parse_bytes_dump, s)
-        pb('\033[$r', ('deccara', '0 0 0 0 0'))
+        pb('\033[$r', ('deccara', '0;0;0;0;0'))
         pb('\033[;;;;4:3;38:5:10;48:2:1:2:3;1$r',
-           ('deccara', '0 0 0 0 4:3'), ('deccara', '0 0 0 0 38:5:10'), ('deccara', '0 0 0 0 48:2:1:2:3'), ('deccara', '0 0 0 0 1'))
+           ('deccara', '0;0;0;0;4:3'), ('deccara', '0;0;0;0;38:5:10'), ('deccara', '0;0;0;0;48:2:1:2:3'), ('deccara', '0;0;0;0;1'))
         for y in range(s.lines):
             line = s.line(y)
             for x in range(s.columns):
@@ -629,7 +629,7 @@ def test_deccara(self):
                 self.ae(c.fg, (10 << 8) | 1)
                 self.ae(c.bg, (1 << 24 | 2 << 16 | 3 << 8 | 2))
         self.ae(s.line(0).cursor_from(0).bold, True)
-        pb('\033[1;2;2;3;22;39$r', ('deccara', '1 2 2 3 22 39'))
+        pb('\033[1;2;2;3;22;39$r', ('deccara', '1;2;2;3;22;39'))
         self.ae(s.line(0).cursor_from(0).bold, True)
         line = s.line(0)
         for x in range(1, s.columns):
@@ -641,7 +641,7 @@ def test_deccara(self):
             c = line.cursor_from(x)
             self.ae(c.bold, False)
         self.ae(line.cursor_from(3).bold, True)
-        pb('\033[2*x\033[3;2;4;3;34$r\033[*x', ('screen_decsace', 2), ('deccara', '3 2 4 3 34'), ('screen_decsace', 0))
+        pb('\033[2*x\033[3;2;4;3;34$r\033[*x', ('screen_decsace', 2), ('deccara', '3;2;4;3;34'), ('screen_decsace', 0))
         for y in range(2, 4):
             line = s.line(y)
             for x in range(s.columns):