diff --git a/src/stores/notification.js b/src/stores/notification.js
index 7287babf..7c302a51 100644
--- a/src/stores/notification.js
+++ b/src/stores/notification.js
@@ -10,6 +10,7 @@ import {
     checkCanInvite,
     displayLocation,
     escapeTag,
+    executeWithBackoff,
     extractFileId,
     extractFileVersion,
     getUserMemo,
@@ -403,6 +404,71 @@ export const useNotificationStore = defineStore('Notification', () => {
         database.seenNotificationV2(notificationId);
     }
 
+    const seeQueue = [];
+    const seenIds = new Set();
+    let seeProcessing = false;
+    const SEE_CONCURRENCY = 5;
+
+    async function processSeeQueue() {
+        if (seeProcessing) return;
+        seeProcessing = true;
+        const worker = async () => {
+            let item;
+            while ((item = seeQueue.shift())) {
+                const { id, version } = item;
+                try {
+                    await executeWithBackoff(
+                        async () => {
+                            if (version >= 2) {
+                                const args =
+                                    await notificationRequest.seeNotificationV2(
+                                        { notificationId: id }
+                                    );
+                                handleNotificationV2Update({
+                                    params: { notificationId: id },
+                                    json: { ...args.json, seen: true }
+                                });
+                            } else {
+                                await notificationRequest.seeNotification({
+                                    notificationId: id
+                                });
+                                handleNotificationSee(id);
+                            }
+                        },
+                        {
+                            maxRetries: 3,
+                            baseDelay: 1000,
+                            shouldRetry: (err) =>
+                                err?.status === 429 ||
+                                (err?.message || '').includes('429')
+                        }
+                    );
+                } catch (err) {
+                    console.warn('Failed to mark notification as seen:', id);
+                    if (version >= 2) {
+                        handleNotificationV2Hide(id);
+                    }
+                }
+            }
+        };
+        await Promise.all(
+            Array.from({ length: SEE_CONCURRENCY }, () => worker())
+        );
+        seeProcessing = false;
+    }
+
+    /**
+     * Queue a notification to be marked as seen.
+     * @param {string} notificationId
+     * @param {number} [version=1]
+     */
+    function queueMarkAsSeen(notificationId, version = 1) {
+        if (seenIds.has(notificationId)) return;
+        seenIds.add(notificationId);
+        seeQueue.push({ id: notificationId, version });
+        processSeeQueue();
+    }
+
     function handleNotificationAccept(args) {
         let ref;
         const array = notificationTable.value.data;
@@ -2754,6 +2820,7 @@ export const useNotificationStore = defineStore('Notification', () => {
         hasUnseenNotifications,
         getNotificationCategory,
         isNotificationExpired,
-        openNotificationLink
+        openNotificationLink,
+        queueMarkAsSeen
     };
 });
diff --git a/src/views/Sidebar/components/NotificationItem.vue b/src/views/Sidebar/components/NotificationItem.vue
index 40e2cb19..31f5771f 100644
--- a/src/views/Sidebar/components/NotificationItem.vue
+++ b/src/views/Sidebar/components/NotificationItem.vue
@@ -249,7 +249,6 @@
     import { Badge } from '@/components/ui/badge';
     import { Separator } from '@/components/ui/separator';
     import { TooltipWrapper } from '@/components/ui/tooltip';
-    import { notificationRequest } from '@/api';
     import { storeToRefs } from 'pinia';
     import { useI18n } from 'vue-i18n';
 
@@ -273,7 +272,7 @@
     const notificationStore = useNotificationStore();
     const { lastLocation } = storeToRefs(useLocationStore());
     const { isGameRunning } = storeToRefs(useGameStore());
-    const { openNotificationLink, isNotificationExpired, handleNotificationV2Hide } = useNotificationStore();
+    const { openNotificationLink, isNotificationExpired } = useNotificationStore();
 
     const senderName = computed(() => {
         const n = props.notification;
@@ -479,34 +478,11 @@
     }
 
     onBeforeUnmount(() => {
-        // Mark as seen
+        // Mark as seen (queued to avoid 429 rate-limiting)
         if (isNotificationExpired(props.notification) || isSeen.value) {
             return;
         }
-        const params = { notificationId: props.notification.id };
-        if (!props.notification.version || props.notification.version < 2) {
-            notificationRequest.seeNotification({ notificationId: props.notification.id }).then((args) => {
-                console.log('Marked notification-v1 as seen:', args.json);
-                notificationStore.handleNotificationSee(props.notification.id);
-            });
-            return;
-        }
-        notificationRequest
-            .seeNotificationV2(params)
-            .then((args) => {
-                console.log('Marked notification-v2 as seen:', args.json);
-                const newArgs = {
-                    params,
-                    json: {
-                        ...args.json,
-                        seen: true
-                    }
-                };
-                notificationStore.handleNotificationV2Update(newArgs);
-            })
-            .catch((err) => {
-                console.error('Failed to mark notification-v2 as seen:', err);
-                handleNotificationV2Hide(props.notification.id);
-            });
+        const version = props.notification.version || 1;
+        notificationStore.queueMarkAsSeen(props.notification.id, version);
     });
 </script>