diff --git a/kitty/boss.py b/kitty/boss.py
index 46ce5d13b..ce155d33d 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -95,6 +95,13 @@ class Boss:
         if dpi_changed:
             self.on_dpi_change(os_window_id)
 
+    def list_os_windows(self):
+        for os_window_id, tm in self.os_window_map.items():
+            yield {
+                'id': os_window_id,
+                'tabs': list(tm.list_tabs()),
+            }
+
     def _new_os_window(self, args, cwd_from=None):
         sw = self.args_to_special_window(args, cwd_from) if args else None
         startup_session = create_session(self.opts, special_window=sw, cwd_from=cwd_from)
diff --git a/kitty/child.py b/kitty/child.py
index c7acaf639..834102ff4 100644
--- a/kitty/child.py
+++ b/kitty/child.py
@@ -19,6 +19,13 @@ def cwd_of_process(pid):
     return os.path.realpath(ans)
 
 
+def cmdline_of_process(pid):
+    if is_macos:
+        # TODO: macOS implementation, see DarwinProcess.c in htop for inspiration
+        raise NotImplementedError()
+    return open('/proc/{}/cmdline'.format(pid), 'rb').read().decode('utf-8').split('\0')
+
+
 def remove_cloexec(fd):
     fcntl.fcntl(fd, fcntl.F_SETFD, fcntl.fcntl(fd, fcntl.F_GETFD) & ~fcntl.FD_CLOEXEC)
 
diff --git a/kitty/remote_control.py b/kitty/remote_control.py
index 97a55bca8..99f5cdf1f 100644
--- a/kitty/remote_control.py
+++ b/kitty/remote_control.py
@@ -36,7 +36,9 @@ def cmd_ls(global_opts, opts, args):
 
 
 def ls(boss, window):
-    raise NotImplementedError()
+    data = list(boss.list_os_windows())
+    data = json.dumps(data, indent=2, sort_keys=True)
+    return data
 
 
 def handle_cmd(boss, window, cmd):
diff --git a/kitty/tabs.py b/kitty/tabs.py
index 536cc440a..4adc7d902 100644
--- a/kitty/tabs.py
+++ b/kitty/tabs.py
@@ -202,6 +202,10 @@ class Tab:  # {{{
     def move_window_backward(self):
         self.move_window(-1)
 
+    def list_windows(self):
+        for w in self:
+            yield w.as_dict()
+
     def __iter__(self):
         yield from iter(self.windows)
 
@@ -379,6 +383,14 @@ class TabManager:  # {{{
     def __len__(self):
         return len(self.tabs)
 
+    def list_tabs(self):
+        for tab in self:
+            yield {
+                'id': tab.id,
+                'title': tab.name or tab.title,
+                'windows': list(tab.list_windows()),
+            }
+
     @property
     def active_tab(self):
         return self.tabs[self.active_tab_idx] if self.tabs else None
diff --git a/kitty/window.py b/kitty/window.py
index 3c0d71ff2..6bc15087d 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -8,6 +8,7 @@ import weakref
 from collections import deque
 from enum import Enum
 
+from .child import cmdline_of_process, cwd_of_process
 from .config import build_ansi_color_table, parse_send_text_bytes
 from .constants import (
     ScreenGeometry, WindowGeometry, appname, get_boss, wakeup
@@ -107,6 +108,22 @@ class Window:
     def __repr__(self):
         return 'Window(title={}, id={})'.format(self.title, self.id)
 
+    def as_dict(self):
+        try:
+            cwd = cwd_of_process(self.child.pid)
+        except Exception:
+            cwd = None
+        try:
+            cmdline = cmdline_of_process(self.child.pid)
+        except Exception:
+            cmdline = None
+        return dict(
+            id=self.id,
+            title=self.override_title or self.title,
+            pid=self.child.pid,
+            cwd=cwd, cmdline=cmdline
+        )
+
     def set_visible_in_layout(self, window_idx, val):
         val = bool(val)
         if val is not self.is_visible_in_layout: