diff --git a/kitty/boss.py b/kitty/boss.py
index 49f028059..6e687ced2 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -122,7 +122,7 @@ from .prewarm import PrewarmProcess
 from .rgb import color_from_int
 from .session import Session, create_sessions, get_os_window_sizing_data
 from .tabs import SpecialWindow, SpecialWindowInstance, Tab, TabDict, TabManager
-from .types import _T, AsyncResponse, WindowSystemMouseEvent, ac
+from .types import _T, AsyncResponse, SingleInstanceData, WindowSystemMouseEvent, ac
 from .typing import PopenType, TypedDict
 from .utils import (
     cleanup_ssh_control_masters,
@@ -748,12 +748,12 @@ class Boss:
             from kitty.remote_control import encode_response_for_peer
             return encode_response_for_peer(response)
 
-        data = json.loads(msg_bytes.decode('utf-8'))
+        data:SingleInstanceData = json.loads(msg_bytes.decode('utf-8'))
         if isinstance(data, dict) and data.get('cmd') == 'new_instance':
             from .cli_stub import CLIOptions
-            startup_id = data.get('startup_id')
-            activation_token = data.get('activation_token', '')
-            args, rest = parse_args(data['args'][1:], result_class=CLIOptions)
+            startup_id = data['environ'].get('DESKTOP_STARTUP_ID', '')
+            activation_token = data['environ'].get('XDG_ACTIVATION_TOKEN', '')
+            args, rest = parse_args(list(data['args'][1:]), result_class=CLIOptions)
             cmdline_args_for_open = data.get('cmdline_args_for_open')
             if cmdline_args_for_open:
                 self.launch_urls(*cmdline_args_for_open, no_replace_window=True)
@@ -779,9 +779,9 @@ class Boss:
                 if data.get('notify_on_os_window_death'):
                     self.os_window_death_actions[os_window_id] = partial(self.notify_on_os_window_death, data['notify_on_os_window_death'])
             if focused_os_window > 0:
-                focus_os_window(focused_os_window, True, activation_token or '')
+                focus_os_window(focused_os_window, True, activation_token)
             elif activation_token and is_wayland() and os_window_id:
-                focus_os_window(os_window_id, True, activation_token or '')
+                focus_os_window(os_window_id, True, activation_token)
         else:
             log_error('Unknown message received from peer, ignoring')
         return None
diff --git a/kitty/main.py b/kitty/main.py
index 93ac4c9c0..4e29a1760 100644
--- a/kitty/main.py
+++ b/kitty/main.py
@@ -50,6 +50,7 @@ from .options.utils import DELETE_ENV_VAR
 from .os_window_size import initial_window_size_func
 from .prewarm import PrewarmProcess, fork_prewarm_process
 from .session import create_sessions, get_os_window_sizing_data
+from .types import SingleInstanceData
 from .utils import (
     cleanup_ssh_control_masters,
     detach,
@@ -87,9 +88,10 @@ def talk_to_instance(args: CLIOptions) -> None:
         with open(args.session) as f:
             session_data = f.read()
 
-    data = {'cmd': 'new_instance', 'args': tuple(sys.argv), 'cmdline_args_for_open': getattr(sys, 'cmdline_args_for_open', []),
-            'startup_id': os.environ.get('DESKTOP_STARTUP_ID'), 'activation_token': os.environ.get('XDG_ACTIVATION_TOKEN'),
-            'cwd': os.getcwd(), 'session_data': session_data, 'environ': dict(os.environ)}
+    data: SingleInstanceData = {
+        'cmd': 'new_instance', 'args': tuple(sys.argv), 'cmdline_args_for_open': getattr(sys, 'cmdline_args_for_open', ()),
+        'cwd': os.getcwd(), 'session_data': session_data, 'environ': dict(os.environ), 'notify_on_os_window_death': None
+    }
     notify_socket = None
     if args.wait_for_single_instance_window_close:
         address = f'\0{appname}-os-window-close-notify-{os.getpid()}-{os.geteuid()}'
diff --git a/kitty/types.py b/kitty/types.py
index 250c5d151..237b64085 100644
--- a/kitty/types.py
+++ b/kitty/types.py
@@ -3,7 +3,7 @@
 
 from enum import Enum
 from functools import update_wrapper
-from typing import TYPE_CHECKING, Any, Callable, Dict, Generic, Iterator, NamedTuple, Tuple, TypeVar, Union
+from typing import TYPE_CHECKING, Any, Callable, Dict, Generic, Iterator, Mapping, NamedTuple, Optional, Sequence, Tuple, TypedDict, TypeVar, Union
 
 if TYPE_CHECKING:
     from kitty.fast_data_types import SingleKey
@@ -11,6 +11,16 @@ if TYPE_CHECKING:
 _T = TypeVar('_T')
 
 
+class SingleInstanceData(TypedDict):
+    cmd: str
+    args: Sequence[str]
+    cmdline_args_for_open: Sequence[str]
+    cwd: str
+    session_data: str
+    environ: Mapping[str, str]
+    notify_on_os_window_death: Optional[str]
+
+
 class OverlayType(Enum):
     transient: str = 'transient'
     main: str = 'main'