diff --git a/src/backend/wayland/wl_backend.c b/src/backend/wayland/wl_backend.c
index 6c8f6b7..ea0fd3b 100644
--- a/src/backend/wayland/wl_backend.c
+++ b/src/backend/wayland/wl_backend.c
@@ -19,6 +19,8 @@
  * Wayland surfaces appear in scr->focused_window list.
  * Phase 40: handle_toplevel_unmap wires XDG toplevel unmap to wUnmanageWindow.
  * Phase 41: prop_get_wm_class and window_fetch_name return XDG app_id/title.
+ * Phase 42: window_get_client_attrs returns WCLIENT_VIEWABLE + surface
+ * geometry for mapped XDG toplevels.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -165,10 +167,12 @@ handle_toplevel_map(struct wl_listener *listener, void *data)
         if (scr) {
             WWindow *wwin = wManageWindow(scr, view->id);
             if (wwin)
-                wwarning("wl_backend: wManageWindow succeeded id=0x%lx class=%s name=%s",
+                wwarning("wl_backend: wManageWindow succeeded id=0x%lx "
+                         "class=%s name=%s geo=%dx%d",
                          view->id,
                          wwin->wm_class    ? wwin->wm_class    : "(none)",
-                         wwin->wm_instance ? wwin->wm_instance : "(none)");
+                         wwin->wm_instance ? wwin->wm_instance : "(none)",
+                         wwin->client.width, wwin->client.height);
         }
     }
 }
@@ -763,9 +767,16 @@ static int  wl_overlay_text_width(WScreen *scr, const char *str, int n) { (void)
 static int
 wl_window_get_client_attrs(WNativeWindow win, WClientAttributes *out)
 {
-    (void)win;
+    /* Phase 42: return real map_state and geometry from XDG surface. */
+    struct wl_toplevel_view *v = wl_find_view_by_id(win);
     memset(out, 0, sizeof(*out));
-    out->map_state = WCLIENT_UNMAPPED;
+    if (v && v->xdg_surface && v->xdg_surface->surface) {
+        out->map_state = WCLIENT_VIEWABLE;
+        out->width     = v->xdg_surface->surface->current.width;
+        out->height    = v->xdg_surface->surface->current.height;
+    } else {
+        out->map_state = WCLIENT_UNMAPPED;
+    }
     return 1;
 }
 
diff --git a/tests/wl-smoke-test.sh b/tests/wl-smoke-test.sh
index 03be0e8..3faa3ce 100755
--- a/tests/wl-smoke-test.sh
+++ b/tests/wl-smoke-test.sh
@@ -24,6 +24,8 @@
 #      logs "toplevel unmapped" and exits cleanly after cleanup
 #  11. (Phase 41) prop_get_wm_class returns XDG app_id: "wManageWindow
 #      succeeded" log includes class=org.freedesktop.weston.simple-shm
+#  12. (Phase 42) window_get_client_attrs returns WCLIENT_VIEWABLE + geometry:
+#      "wManageWindow succeeded" log includes geo= with non-zero size
 #
 # This test grows as wl_backend vtable slots are implemented.
 #
@@ -169,6 +171,12 @@ if command -v weston-simple-shm >/dev/null 2>&1; then
     grep -q 'class=org.freedesktop.weston.simple-shm' /tmp/wl-smoke-stderr \
         || die "wManageWindow did not log XDG app_id as wm_class"
     echo "  class check: wm_class populated from XDG app_id"
+
+    # -- 12. Phase 42: geometry from XDG surface -------------------------
+    # geo= must appear and be non-zero (weston-simple-shm commits a frame)
+    GEO=$(grep -o 'geo=[0-9]*x[0-9]*' /tmp/wl-smoke-stderr | head -1)
+    [ -n "$GEO" ] || die "wManageWindow did not log geo= geometry"
+    echo "  geometry check: client geometry logged as $GEO"
 else
     echo "  client check: skipped (weston-simple-shm not installed)"
 fi