@@ -21,6 +21,7 @@ runner) lives in [`.agents/skills/`](../../.agents/skills); read
 | `flutter_window_title_bar_snap_test.ps1` | `window_title_bar_example` (#70) | Windows 11 | End to end in a real Flutter app: with the title bar Hidden the strip draws a Maximize / Restore chip wrapped in `MaximizeButtonArea`; resting the cursor on it opens the snap layouts and leaving closes them, a click maximizes (the chip reads Restore) and another restores to the earlier width. Owner-guarded clicks, no keyboard. Saves a screenshot. Set `TITLE_BAR_EXAMPLE_EXE` for a build outside `$RemoteWorkspace`. |
 | `flutter_window_title_bar_system_menu_test.ps1` | `window_title_bar_example` (#66) | Windows | End to end in a real Flutter app: a secondary click on the `DragToMoveArea` strip opens the native system menu at the pointer; its item states match the window (restored: Restore off; maximized: Move, Size, Maximize off); choosing Maximize maximizes and, from a second menu, Restore restores to the earlier width. Items are taken by their fixed order, so any display language works. Owner-guarded clicks, no keyboard. Set `TITLE_BAR_EXAMPLE_EXE` for a build outside `$RemoteWorkspace`. |
 | `flutter_window_title_bar_close_test.ps1` | `window_title_bar_example` (#65) | Windows | End to end in a real Flutter app: with Closing set to Keep open, the example cancels `WindowCloseRequestedEvent`; a real click on the window's own close button (found through DWM's caption button bounds) and the system menu's Close each leave the window open and count one cancelled request; with Allow, the close button closes the window and the app exits with code 0. Owner-guarded clicks, no keyboard. Set `TITLE_BAR_EXAMPLE_EXE` for a build outside `$RemoteWorkspace`. |
+| `flutter_window_title_bar_close_test_linux.py` | `window_title_bar_example` (#65) | Linux (GNOME) | The Linux twin of the close test: with Keep open, two real clicks on the header bar's close button (found by its accessible name through AT-SPI) are cancelled and counted; with Allow the click closes the window and the app exits with code 0. The Flutter view is located through AT-SPI too, since the runner's header bar sits inside the X11 client area. The system menu is gnome-shell's and is not driven. Set `TITLE_BAR_EXAMPLE_EXE` for a build outside `$REMOTE_WORKSPACE`. |
 | `core_window_shadow_layout_test_linux.cpp` | core shadow | Linux Wayland / X11 | No-input regression: stable shadow geometry, contour pixels inside transparent content, input pass-through, disable and decoration restoration |
 | `flutter_window_shape_smoke_macos.py` / `flutter_window_shape_test_windows.ps1` | `shaped_window_example` | macOS / Windows | macOS: no-input shape and pixel-alpha smoke test; Windows: native regions, real button clicks/drag, resize, clear/reapply, click-through to the underlying app window |
 | `flutter_detachable_window_test.py` / `.ps1` | `detachable_window_example` | macOS / Windows | tear a panel off, exact content size, header stays under the cursor, dock into the other window, `State` preserved |
 
@@ -0,0 +1,159 @@
+#!/usr/bin/env python3
+"""GUI test (Linux, GNOME) of cancellable window close (#65) in
+flutter_window_title_bar_example: with Closing set to Keep open the example
+cancels every WindowCloseRequestedEvent, so a real click on the header bar's
+close button leaves the window open and counts one cancelled request; with
+Allow the same click closes the window and the app exits with code 0. The
+Linux twin of flutter_window_title_bar_close_test.ps1 (Windows).
+
+    .agents/skills/remote-hosts/scripts/remote.sh linux desktop \
+        tools/gui/flutter_window_title_bar_close_test_linux.py 200
+
+The close button is GTK's own (the Flutter runner uses a header bar under
+GNOME), found by its accessible name through AT-SPI. The system menu is
+gnome-shell's, outside the app's windows, so it is not driven here. The
+example is expected built in debug in the host's checkout ($REMOTE_WORKSPACE),
+or set TITLE_BAR_EXAMPLE_EXE. The app runs under GDK_BACKEND=x11.
+"""
+
+import os
+import sys
+import time
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))  # the flat kit on a remote host
+
+from guiapp import Abort, Checks, GuiApp, assert_idle, flutter_executable, pause  # noqa: E402
+
+import gi  # noqa: E402
+
+gi.require_version('Atspi', '2.0')
+from gi.repository import Atspi  # noqa: E402
+
+NAME = 'window_title_bar_example'
+
+
+def executable():
+    if os.environ.get('TITLE_BAR_EXAMPLE_EXE'):
+        return os.environ['TITLE_BAR_EXAMPLE_EXE']
+    workspace = os.environ.get('REMOTE_WORKSPACE') or os.path.dirname(
+        os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+    return flutter_executable(
+        os.path.join(workspace, 'examples', 'flutter_window_title_bar_example'), NAME)
+
+
+def close_button(pid, timeout=10):
+    """Screen center of the header bar's close button, through AT-SPI."""
+    deadline = time.time() + timeout
+    while time.time() < deadline:
+        desktop = Atspi.get_desktop(0)
+        for i in range(desktop.get_child_count()):
+            app = desktop.get_child_at_index(i)
+            if app is None or app.get_process_id() != pid:
+                continue
+            stack = [app]
+            while stack:
+                node = stack.pop()
+                if (node.get_role() == Atspi.Role.PUSH_BUTTON and
+                        (node.get_name() or '').lower() == 'close'):
+                    r = node.get_extents(Atspi.CoordType.SCREEN)
+                    if r.width > 0 and r.height > 0:
+                        return r.x + r.width / 2, r.y + r.height / 2
+                stack.extend(node.get_child_at_index(j) for j in range(node.get_child_count()))
+        time.sleep(0.5)
+    raise Abort('no accessible close button: is the AT-SPI bus running?')
+
+
+def accessibles(pid):
+    """Every accessible of the app, depth first."""
+    desktop = Atspi.get_desktop(0)
+    for i in range(desktop.get_child_count()):
+        app = desktop.get_child_at_index(i)
+        if app is None or app.get_process_id() != pid:
+            continue
+        stack = [app]
+        while stack:
+            node = stack.pop()
+            yield node
+            stack.extend(node.get_child_at_index(j) for j in range(node.get_child_count()))
+
+
+def view_origin(app, timeout=10):
+    """Screen position of the Flutter view.
+
+    Under GNOME the runner puts a GTK header bar above the view, inside the X11
+    client area, so the view does not start where the harness's to_screen()
+    assumes. Its accessible, the one exactly the view's size, tells.
+    """
+    width, height = app.views()[0].size
+    deadline = time.time() + timeout
+    while time.time() < deadline:
+        for node in accessibles(app.proc.pid):
+            r = node.get_extents(Atspi.CoordType.SCREEN)
+            if abs(r.width - width) <= 1 and abs(r.height - height) <= 1:
+                return r.x, r.y
+        time.sleep(0.5)
+    raise Abort(f'no accessible of the view size {width}x{height}')
+
+
+def text_center(app, text):
+    x, y = app.views()[0].center(text)
+    ox, oy = view_origin(app)
+    return ox + x, oy + y
+
+
+def has_text(app, text):
+    return any(t == text for t, _ in app.views()[0].texts)
+
+
+def cancelled(app):
+    view = app.views()[0]
+    for text, _ in view.texts:
+        if text.startswith('Cancelled closes: '):
+            return int(text.split(':')[1])
+    raise Abort('the cancelled-closes counter is missing')
+
+
+def main():
+    assert_idle()
+    checks = Checks()
+    app = GuiApp(executable())
+    app.launch()
+    try:
+        app.click(text_center(app, 'Keep open'))
+        pause(0.8)
+        checks.check('Keep open is chosen',
+                     has_text(app, 'Close requests are cancelled; try the × or the menu'))
+        checks.check('the counter starts at 0', cancelled(app) == 0)
+
+        app.click(close_button(app.proc.pid))
+        pause(1.5)
+        checks.check('with Keep open, the close button leaves the window open',
+                     app.proc.poll() is None and len(app.windows()) == 1)
+        checks.check('and the example cancelled one request', cancelled(app) == 1)
+
+        app.click(close_button(app.proc.pid))
+        pause(1.5)
+        checks.check('a second click is cancelled too', app.proc.poll() is None and
+                     cancelled(app) == 2)
+
+        app.click(text_center(app, 'Allow'))
+        pause(0.8)
+        checks.check('Allow is chosen', has_text(app, 'Closing the window closes it'))
+        app.click(close_button(app.proc.pid))
+        try:
+            code = app.proc.wait(10)
+        except Exception:
+            code = None
+        checks.check('with Allow, the close button closes the window and the app exits',
+                     code is not None, f'exit code {code}')
+        checks.check('with exit code 0', code == 0, f'exit code {code}')
+    except Abort as error:
+        checks.check('the scenario ran to the end', False, str(error))
+    finally:
+        app.quit()
+    print('FAILED' if checks.failures else 'OK', flush=True)
+    return 1 if checks.failures else 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())