diff --git a/src/components/HabitGrid.jsx b/src/components/HabitGrid.jsx
index f344a2d..3b77170 100644
--- a/src/components/HabitGrid.jsx
+++ b/src/components/HabitGrid.jsx
@@ -40,19 +40,26 @@ const HabitGrid = ({ habit, onUpdate, fullView = false }) => {
 
   const handleCellClick = async (date) => {
     const dateStr = formatDate(date);
-    // Optimistically update completions for instant UI
-    const habits = JSON.parse(localStorage.getItem('habitgrid_data') || '[]');
-    const idx = habits.findIndex(h => h.id === habit.id);
-    if (idx !== -1) {
-      const completions = Array.isArray(habits[idx].completions) ? [...habits[idx].completions] : [];
-      const cidx = completions.indexOf(dateStr);
-      if (cidx > -1) completions.splice(cidx, 1); else completions.push(dateStr);
-      habits[idx].completions = completions;
-      localStorage.setItem('habitgrid_data', JSON.stringify(habits));
+    const user = await getAuthUser();
+    if (user) {
+      // Optimistically update completions for instant UI
+      const habits = JSON.parse(localStorage.getItem('habitgrid_data') || '[]');
+      const idx = habits.findIndex(h => h.id === habit.id);
+      if (idx !== -1) {
+        const completions = Array.isArray(habits[idx].completions) ? [...habits[idx].completions] : [];
+        const cidx = completions.indexOf(dateStr);
+        if (cidx > -1) completions.splice(cidx, 1); else completions.push(dateStr);
+        habits[idx].completions = completions;
+        localStorage.setItem('habitgrid_data', JSON.stringify(habits));
+      }
+      onUpdate();
+      // Sync in background
+      toggleCompletion(habit.id, dateStr);
+    } else {
+      // Local-only: just call toggleCompletion, then update UI
+      await toggleCompletion(habit.id, dateStr);
+      onUpdate();
     }
-    onUpdate();
-    // Sync in background
-    toggleCompletion(habit.id, dateStr);
   };
 
   return (
diff --git a/src/components/MiniGrid.jsx b/src/components/MiniGrid.jsx
index bf372ae..37c59e4 100644
--- a/src/components/MiniGrid.jsx
+++ b/src/components/MiniGrid.jsx
@@ -69,19 +69,26 @@ const MiniGrid = ({ habit, onUpdate }) => {
     const dateStr = formatDate(date);
     const isTodayCell = isToday(date);
     const wasCompleted = habit.completions.includes(dateStr);
-    // Optimistically update completions for instant UI
-    const habits = JSON.parse(localStorage.getItem('habitgrid_data') || '[]');
-    const idx = habits.findIndex(h => h.id === habit.id);
-    if (idx !== -1) {
-      const completions = Array.isArray(habits[idx].completions) ? [...habits[idx].completions] : [];
-      const cidx = completions.indexOf(dateStr);
-      if (cidx > -1) completions.splice(cidx, 1); else completions.push(dateStr);
-      habits[idx].completions = completions;
-      localStorage.setItem('habitgrid_data', JSON.stringify(habits));
+    const user = await getAuthUser();
+    if (user) {
+      // Optimistically update completions for instant UI
+      const habits = JSON.parse(localStorage.getItem('habitgrid_data') || '[]');
+      const idx = habits.findIndex(h => h.id === habit.id);
+      if (idx !== -1) {
+        const completions = Array.isArray(habits[idx].completions) ? [...habits[idx].completions] : [];
+        const cidx = completions.indexOf(dateStr);
+        if (cidx > -1) completions.splice(cidx, 1); else completions.push(dateStr);
+        habits[idx].completions = completions;
+        localStorage.setItem('habitgrid_data', JSON.stringify(habits));
+      }
+      onUpdate();
+      // Sync in background
+      toggleCompletion(habit.id, dateStr);
+    } else {
+      // Local-only: just call toggleCompletion, then update UI
+      await toggleCompletion(habit.id, dateStr);
+      onUpdate();
     }
-    onUpdate();
-    // Sync in background
-    toggleCompletion(habit.id, dateStr);
     // Only show encouragement toast if validating (adding) today's dot
     if (isTodayCell && !wasCompleted) {
       try {