From 8bf4df45138eecb69b324e2021cd89166df4fc15 Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Wed, 14 Oct 2026 05:25:11 +0200
Subject: [PATCH] feat: add a notifications panel for plugin notifications and
 app errors

---
 .../__tests__/top-bar-plugin-actions.test.tsx |   7 +-
 components/layout/mobile-header.tsx           |  26 +-
 components/layout/mv-top-bar.tsx              |   2 +
 components/layout/navigation-rail.tsx         |   3 +
 .../__tests__/notification-center.test.tsx    | 121 ++++++++
 .../notifications/notification-center.tsx     | 262 ++++++++++++++++++
 .../plugin-host-notifications.test.ts         |  27 ++
 lib/plugin-sandbox/host-api-notify.ts         |   4 +
 locales/ar/common.json                        |  11 +
 locales/ca/common.json                        |  11 +
 locales/cs/common.json                        |  11 +
 locales/da/common.json                        |  11 +
 locales/de/common.json                        |  11 +
 locales/en/common.json                        |  11 +
 locales/es/common.json                        |  11 +
 locales/fa/common.json                        |  11 +
 locales/fr/common.json                        |  11 +
 locales/he/common.json                        |  11 +
 locales/hu/common.json                        |  11 +
 locales/it/common.json                        |  11 +
 locales/ja/common.json                        |  11 +
 locales/ko/common.json                        |  11 +
 locales/lv/common.json                        |  11 +
 locales/mn/common.json                        |  11 +
 locales/nb/common.json                        |  11 +
 locales/nl/common.json                        |  11 +
 locales/pl/common.json                        |  11 +
 locales/pt/common.json                        |  11 +
 locales/ro/common.json                        |  11 +
 locales/ru/common.json                        |  11 +
 locales/sk/common.json                        |  11 +
 locales/tr/common.json                        |  11 +
 locales/uk/common.json                        |  11 +
 locales/zh-TW/common.json                     |  11 +
 locales/zh/common.json                        |  11 +
 .../notification-center-store.test.ts         |  70 +++++
 stores/notification-center-store.ts           | 114 ++++++++
 stores/toast-store.ts                         |   5 +
 38 files changed, 930 insertions(+), 8 deletions(-)
 create mode 100644 components/notifications/__tests__/notification-center.test.tsx
 create mode 100644 components/notifications/notification-center.tsx
 create mode 100644 stores/__tests__/notification-center-store.test.ts
 create mode 100644 stores/notification-center-store.ts

diff --git a/components/layout/__tests__/top-bar-plugin-actions.test.tsx b/components/layout/__tests__/top-bar-plugin-actions.test.tsx
index e3f09f61e..d4e4c48ae 100644
--- a/components/layout/__tests__/top-bar-plugin-actions.test.tsx
+++ b/components/layout/__tests__/top-bar-plugin-actions.test.tsx
@@ -56,8 +56,11 @@ describe('phone header', () => {
     render(<MobileHeader title="Inbox" />);
     fireEvent.click(screen.getByRole('button', { name: 'more' }));
 
-    expect(screen.getAllByRole('menuitem').map((m) => m.textContent)).toEqual(['title']);
-    fireEvent.click(screen.getByRole('menuitem', { name: 'title' }));
+    // Notifications and the command palette (both labelled "title" here, as
+    // the translations are keys in tests); no plugin entries.
+    const items = screen.getAllByRole('menuitem');
+    expect(items.map((m) => m.textContent)).toEqual(['title', 'title']);
+    fireEvent.click(items[1]);
     expect(opened).toHaveBeenCalled();
     window.removeEventListener('bulwark:command-palette', opened);
   });
diff --git a/components/layout/mobile-header.tsx b/components/layout/mobile-header.tsx
index 9fa7fbf64..3dc6db4cd 100644
--- a/components/layout/mobile-header.tsx
+++ b/components/layout/mobile-header.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 import { useCallback, useEffect, useRef, useState } from "react";
-import { Menu, ArrowLeft, Plus, Search, X, MoreVertical, Terminal } from "@/components/icons";
+import { Menu, ArrowLeft, Plus, Search, X, MoreVertical, Terminal, Bell } from "@/components/icons";
 import { Button } from "@/components/ui/button";
 import { useUIStore } from "@/stores/ui-store";
 import { useSettingsStore } from "@/stores/settings-store";
@@ -13,18 +13,22 @@ import { PluginActions } from "@/components/plugins/plugin-actions";
 import { useMenuNavigation } from "@/hooks/use-menu-navigation";
 import { ContextMenuItem } from "@/components/ui/context-menu";
 import { openCommandPalette } from "@/lib/app-commands";
+import { NotificationSheet, formatBadgeCount, useUnreadNotificationCount } from "@/components/notifications/notification-center";
 
 /** Plugin buttons in the top bar are not about any one item. */
 const TOP_BAR_CONTEXT: Record<string, unknown> = {};
 
 /**
- * The phone header's overflow menu: the command palette (no Ctrl+K on a
- * phone) and what the desktop top bar shows as buttons (plugin
- * top-bar-actions) and has no room for here.
+ * The phone header's overflow menu: the notifications (the desktop bell), the
+ * command palette (no Ctrl+K on a phone) and what the desktop top bar shows
+ * as buttons (plugin top-bar-actions) and has no room for here.
  */
 function MobileHeaderMenu() {
   const t = useTranslations('top_bar');
   const tPalette = useTranslations('command_palette');
+  const tNotifications = useTranslations('notification_center');
+  const unread = useUnreadNotificationCount();
+  const [showNotifications, setShowNotifications] = useState(false);
   const [open, setOpen] = useState(false);
   const triggerRef = useRef<HTMLButtonElement>(null);
   const close = useCallback(() => setOpen(false), []);
@@ -47,12 +51,15 @@ function MobileHeaderMenu() {
         variant="ghost"
         size="icon"
         onClick={() => setOpen((v) => !v)}
-        className={cn("h-11 w-11", open && "bg-accent")}
-        aria-label={t('more')}
+        className={cn("relative h-11 w-11", open && "bg-accent")}
+        aria-label={unread > 0 ? `${t('more')} (${tNotifications('unread_count', { count: unread })})` : t('more')}
         aria-haspopup="menu"
         aria-expanded={open}
       >
         <MoreVertical className="h-5 w-5" />
+        {unread > 0 && (
+          <span className="absolute top-2 end-2 w-2 h-2 rounded-full bg-red-500 ring-2 ring-background" aria-hidden="true" />
+        )}
       </Button>
       {open && (
         <div
@@ -62,6 +69,12 @@ function MobileHeaderMenu() {
           aria-label={t('more')}
           className="absolute end-0 top-full mt-1 z-50 min-w-[200px] max-w-[calc(100vw-2rem)] rounded-md border border-border bg-background py-1 shadow-lg"
         >
+          <ContextMenuItem
+            icon={Bell}
+            label={tNotifications('title')}
+            shortcut={unread > 0 ? formatBadgeCount(unread) : undefined}
+            onClick={() => { close(); setShowNotifications(true); }}
+          />
           <ContextMenuItem
             icon={Terminal}
             label={tPalette('title')}
@@ -70,6 +83,7 @@ function MobileHeaderMenu() {
           <PluginActions surface="top-bar-actions" context={TOP_BAR_CONTEXT} variant="menu" onRan={close} />
         </div>
       )}
+      {showNotifications && <NotificationSheet onClose={() => setShowNotifications(false)} />}
     </div>
   );
 }
diff --git a/components/layout/mv-top-bar.tsx b/components/layout/mv-top-bar.tsx
index d97aefa67..399ec8f2c 100644
--- a/components/layout/mv-top-bar.tsx
+++ b/components/layout/mv-top-bar.tsx
@@ -34,6 +34,7 @@ import { AccountSwitcher } from "@/components/layout/account-switcher";
 import { SearchBox, type ContactSearchField } from "@/components/search/search-box";
 import { PluginActions } from "@/components/plugins/plugin-actions";
 import { usePluginPages, pluginPageHref, isPluginPageActive } from "@/hooks/use-plugin-pages";
+import { NotificationBell } from "@/components/notifications/notification-center";
 import type { ContactSuggestion } from "@/lib/search-suggestions";
 
 /** The top bar is not about any one item: plugin clicks carry no context. */
@@ -243,6 +244,7 @@ export function MvTopBar({
       <div className="flex-1 min-w-0" />
 
       <div className="flex items-center gap-1 shrink-0">
+        <NotificationBell placement="below" className="w-12 h-12 rounded-full" />
         {onShowShortcuts && (
           <button
             type="button"
diff --git a/components/layout/navigation-rail.tsx b/components/layout/navigation-rail.tsx
index 765f6f2a6..8152d454d 100644
--- a/components/layout/navigation-rail.tsx
+++ b/components/layout/navigation-rail.tsx
@@ -28,6 +28,7 @@ import { getPathPrefix, withBasePath } from "@/lib/browser-navigation";
 import { Avatar } from "@/components/ui/avatar";
 import { toUnicodeEmail } from "@/lib/idn";
 import { usePluginPages, pluginPageHref, isPluginPageActive } from "@/hooks/use-plugin-pages";
+import { NotificationBell } from "@/components/notifications/notification-center";
 
 interface NavItem {
   id: string;
@@ -710,6 +711,8 @@ export function NavigationRail({
           </a>
         )}
 
+        <NotificationBell placement="side" className="w-10 h-10 rounded-md" />
+
         <Link
           href="/settings"
           onClick={handleNavClick('settings')}
diff --git a/components/notifications/__tests__/notification-center.test.tsx b/components/notifications/__tests__/notification-center.test.tsx
new file mode 100644
index 000000000..ffdd36d7f
--- /dev/null
+++ b/components/notifications/__tests__/notification-center.test.tsx
@@ -0,0 +1,121 @@
+import React from 'react';
+import { act, fireEvent, render, screen, within } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+// The bell and its panel, where they sit (rail, Mountain View's bar, the
+// phone header's menu) and what a click on an entry does.
+
+vi.mock('next-intl', () => ({
+  useTranslations: () => (key: string, params?: Record<string, unknown>) =>
+    params ? `${key}(${Object.values(params).join(',')})` : key,
+  useFormatter: () => ({ relativeTime: () => 'just now' }),
+  useLocale: () => 'en',
+}));
+vi.mock('@/hooks/use-config', () => ({ useConfig: () => ({ appName: 'Bulwark' }) }));
+vi.mock('@/hooks/use-stalwart-admin', () => ({ useStalwartAdmin: () => false }));
+vi.mock('@/components/layout/account-switcher', () => ({ AccountSwitcher: () => null }));
+vi.mock('@/components/plugins/plugin-slot', () => ({ PluginSlot: () => null }));
+vi.mock('@/components/keyboard-shortcuts-modal', () => ({ KeyboardShortcutsModal: () => null }));
+vi.mock('@/components/search/search-box', () => ({ SearchBox: () => null }));
+
+const { NavigationRail } = await import('@/components/layout/navigation-rail');
+const { MvTopBar } = await import('@/components/layout/mv-top-bar');
+const { MobileHeader } = await import('@/components/layout/mobile-header');
+const { useNotificationCenterStore } = await import('@/stores/notification-center-store');
+const { useUpdateStore } = await import('@/stores/update-store');
+const { toastHooks } = await import('@/lib/plugin-hooks');
+
+const add = useNotificationCenterStore.getState().add;
+const clicked = vi.fn();
+
+beforeEach(() => {
+  useUpdateStore.setState({ startPolling: vi.fn() } as never);
+  act(() => useNotificationCenterStore.getState().clear());
+  clicked.mockClear();
+  toastHooks.onNotificationClick.register('rss', clicked);
+});
+afterEach(() => toastHooks.onNotificationClick.removePlugin('rss'));
+
+const bell = () => screen.getByRole('button', { name: /^title/ });
+
+describe('notification bell', () => {
+  it('sits in the navigation rail without a count when nothing is unread', () => {
+    render(<NavigationRail collapsed />);
+    expect(bell()).toHaveAccessibleName('title');
+    expect(bell()).toHaveTextContent('');
+  });
+
+  it('shows the unread count and lists entries with their source, newest first', () => {
+    act(() => {
+      add({ level: 'error', title: 'Could not send', body: 'Server said no' });
+      add({ level: 'info', title: '3 new posts', body: 'Hacker News', pluginId: 'rss', pluginName: 'RSS Reader', tag: 'feed:hn' });
+    });
+    render(<NavigationRail collapsed />);
+
+    expect(bell()).toHaveAccessibleName('title (unread_count(2))');
+    expect(bell()).toHaveTextContent('2');
+    fireEvent.click(bell());
+
+    const panel = screen.getByRole('dialog', { name: 'title' });
+    const items = within(panel).getAllByRole('listitem');
+    expect(items.map((li) => li.getAttribute('data-entry-source'))).toEqual(['rss', 'app']);
+    expect(items[0]).toHaveTextContent('3 new posts');
+    expect(items[0]).toHaveTextContent('RSS Reader');
+    expect(items[1]).toHaveTextContent('Could not send');
+    expect(items[1]).toHaveTextContent('Bulwark');
+    expect(items[1]).toHaveTextContent('level_error');
+  });
+
+  it('tells the plugin when its entry is clicked, with the tag, and marks it read', async () => {
+    act(() => add({ level: 'info', title: '3 new posts', body: '', pluginId: 'rss', pluginName: 'RSS Reader', tag: 'feed:hn' }));
+    render(<NavigationRail collapsed />);
+    fireEvent.click(bell());
+
+    await act(async () => { fireEvent.click(screen.getByRole('button', { name: /3 new posts/ })); });
+    expect(clicked).toHaveBeenCalledWith({ tag: 'feed:hn' });
+    expect(useNotificationCenterStore.getState().entries[0].read).toBe(true);
+    expect(screen.queryByRole('dialog')).toBeNull();
+  });
+
+  it('marks all read and clears', () => {
+    act(() => {
+      add({ level: 'warning', title: 'a', body: '' });
+      add({ level: 'error', title: 'b', body: '' });
+    });
+    render(<NavigationRail collapsed />);
+    fireEvent.click(bell());
+
+    act(() => { fireEvent.click(screen.getByRole('button', { name: 'mark_all_read' })); });
+    expect(bell()).toHaveAccessibleName('title');
+    expect(screen.getAllByRole('listitem')).toHaveLength(2);
+
+    act(() => { fireEvent.click(screen.getByRole('button', { name: 'clear' })); });
+    expect(screen.queryAllByRole('listitem')).toHaveLength(0);
+    expect(screen.getByText('empty')).toBeInTheDocument();
+  });
+
+  it('sits in Mountain View\'s top bar', () => {
+    act(() => add({ level: 'error', title: 'a', body: '' }));
+    render(<MvTopBar />);
+    expect(bell()).toHaveAccessibleName('title (unread_count(1))');
+  });
+
+  it('is an entry in the phone header menu that opens the list full screen', () => {
+    act(() => add({ level: 'error', title: 'Could not send', body: '' }));
+    render(<MobileHeader title="Inbox" />);
+
+    const more = screen.getByRole('button', { name: /^more/ });
+    expect(more).toHaveAccessibleName('more (unread_count(1))');
+    fireEvent.click(more);
+    // First entry: notifications (with the count), then the command palette.
+    const [notifications] = screen.getAllByRole('menuitem');
+    expect(notifications).toHaveTextContent('1');
+    fireEvent.click(notifications);
+
+    const sheet = screen.getByRole('dialog', { name: 'title' });
+    expect(sheet).toHaveAttribute('aria-modal', 'true');
+    expect(within(sheet).getByText('Could not send')).toBeInTheDocument();
+    fireEvent.click(within(sheet).getByRole('button', { name: 'close' }));
+    expect(screen.queryByRole('dialog')).toBeNull();
+  });
+});
diff --git a/components/notifications/notification-center.tsx b/components/notifications/notification-center.tsx
new file mode 100644
index 000000000..8d42cf953
--- /dev/null
+++ b/components/notifications/notification-center.tsx
@@ -0,0 +1,262 @@
+"use client";
+
+import { useCallback, useEffect, useLayoutEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
+import { useFormatter, useTranslations } from "next-intl";
+import { AlertCircle, AlertTriangle, Bell, CheckCheck, Puzzle, Trash2, X } from "@/components/icons";
+import { useConfig } from "@/hooks/use-config";
+import { useFocusTrap } from "@/hooks/use-focus-trap";
+import { isDocumentRTL } from "@/i18n/direction";
+import { toastHooks } from "@/lib/plugin-hooks";
+import { cn } from "@/lib/utils";
+import {
+  selectUnreadCount,
+  useNotificationCenterStore,
+  type CenterEntry,
+} from "@/stores/notification-center-store";
+
+/** "99+" past two digits, like the other badges. */
+export function formatBadgeCount(count: number): string {
+  return count > 99 ? "99+" : String(count);
+}
+
+export function useUnreadNotificationCount(): number {
+  return useNotificationCenterStore(selectUnreadCount);
+}
+
+function EntryIcon({ entry }: { entry: CenterEntry }) {
+  if (entry.level === "error") return <AlertCircle className="w-4 h-4 text-destructive" />;
+  if (entry.level === "warning") return <AlertTriangle className="w-4 h-4 text-warning" />;
+  if (entry.pluginId) return <Puzzle className="w-4 h-4 text-muted-foreground" />;
+  return <Bell className="w-4 h-4 text-muted-foreground" />;
+}
+
+/**
+ * The list behind the bell: recent notifications from plugins and the app's
+ * error and warning toasts, newest first. Clicking a plugin's entry tells
+ * that plugin (onNotificationClick), as a click on the system notification
+ * does.
+ */
+export function NotificationPanel({ onClose, className, sheet = false }: { onClose: () => void; className?: string; sheet?: boolean }) {
+  const t = useTranslations("notification_center");
+  const format = useFormatter();
+  const { appName } = useConfig();
+  const entries = useNotificationCenterStore((s) => s.entries);
+  const unread = useNotificationCenterStore(selectUnreadCount);
+  const markRead = useNotificationCenterStore((s) => s.markRead);
+  const markAllRead = useNotificationCenterStore((s) => s.markAllRead);
+  const clear = useNotificationCenterStore((s) => s.clear);
+  const [now] = useState(() => Date.now());
+
+  const openEntry = (entry: CenterEntry) => {
+    markRead(entry.id);
+    if (!entry.pluginId) return;
+    onClose();
+    void toastHooks.onNotificationClick.emitTo(entry.pluginId, { tag: entry.tag ?? "" });
+  };
+
+  return (
+    <div className={cn("flex flex-col bg-background text-foreground", className)} data-notification-panel="">
+      <div className="flex items-center gap-1 px-3 h-12 border-b border-border shrink-0">
+        <h2 className="flex-1 min-w-0 truncate text-sm font-semibold">{t("title")}</h2>
+        <button
+          type="button"
+          onClick={markAllRead}
+          disabled={unread === 0}
+          className="inline-flex items-center gap-1 h-8 px-2 rounded-md text-xs text-muted-foreground hover:bg-muted hover:text-foreground disabled:opacity-50 disabled:pointer-events-none transition-colors"
+        >
+          <CheckCheck className="w-4 h-4" />
+          <span>{t("mark_all_read")}</span>
+        </button>
+        <button
+          type="button"
+          onClick={clear}
+          disabled={entries.length === 0}
+          className="inline-flex items-center gap-1 h-8 px-2 rounded-md text-xs text-muted-foreground hover:bg-muted hover:text-foreground disabled:opacity-50 disabled:pointer-events-none transition-colors"
+        >
+          <Trash2 className="w-4 h-4" />
+          <span>{t("clear")}</span>
+        </button>
+        {sheet && (
+          <button
+            type="button"
+            onClick={onClose}
+            className="grid place-items-center h-10 w-10 rounded-md text-muted-foreground hover:bg-muted hover:text-foreground transition-colors"
+            aria-label={t("close")}
+          >
+            <X className="w-5 h-5" />
+          </button>
+        )}
+      </div>
+      {entries.length === 0 ? (
+        <p className="px-4 py-8 text-center text-sm text-muted-foreground">{t("empty")}</p>
+      ) : (
+        <ul className="flex-1 min-h-0 overflow-y-auto py-1" aria-label={t("title")}>
+          {entries.map((entry) => {
+            const source = entry.pluginName ?? appName;
+            const content = (
+              <>
+                <span className="mt-0.5 flex-shrink-0" aria-hidden="true"><EntryIcon entry={entry} /></span>
+                <span className="flex-1 min-w-0">
+                  <span className="flex items-baseline gap-2">
+                    <span className={cn("flex-1 min-w-0 truncate text-sm", !entry.read && "font-semibold")}>{entry.title}</span>
+                    <time dateTime={new Date(entry.time).toISOString()} className="flex-shrink-0 text-[11px] text-muted-foreground tabular-nums">
+                      {format.relativeTime(new Date(entry.time), now)}
+                    </time>
+                  </span>
+                  {entry.body && <span className="block text-xs text-muted-foreground line-clamp-2 break-words">{entry.body}</span>}
+                  <span className="block text-[11px] text-muted-foreground truncate">
+                    {entry.level !== "info" && <span className="sr-only">{t(entry.level === "error" ? "level_error" : "level_warning")}: </span>}
+                    {source}
+                  </span>
+                </span>
+                {!entry.read && (
+                  <span className="mt-1.5 w-2 h-2 rounded-full bg-primary flex-shrink-0" aria-label={t("unread")} />
+                )}
+              </>
+            );
+            return (
+              <li key={entry.id} data-entry-source={entry.pluginId ?? "app"}>
+                {entry.pluginId ? (
+                  <button
+                    type="button"
+                    onClick={() => openEntry(entry)}
+                    className="w-full flex items-start gap-2.5 px-3 py-2 text-start hover:bg-muted focus-visible:bg-muted focus-visible:outline-none transition-colors"
+                  >
+                    {content}
+                  </button>
+                ) : (
+                  <div className="flex items-start gap-2.5 px-3 py-2">
+                    {content}
+                  </div>
+                )}
+              </li>
+            );
+          })}
+        </ul>
+      )}
+    </div>
+  );
+}
+
+/** The phone version: the panel over the whole screen. */
+export function NotificationSheet({ onClose }: { onClose: () => void }) {
+  const t = useTranslations("notification_center");
+  const ref = useFocusTrap({ isActive: true, onEscape: onClose, restoreFocus: true });
+  return createPortal(
+    <div
+      ref={ref}
+      role="dialog"
+      aria-modal="true"
+      aria-label={t("title")}
+      className="fixed inset-0 z-50 flex flex-col bg-background pt-[env(safe-area-inset-top)]"
+    >
+      <NotificationPanel onClose={onClose} sheet className="flex-1 min-h-0" />
+    </div>,
+    document.body,
+  );
+}
+
+/**
+ * The bell with the unread count. `side` opens the panel beside the button
+ * (navigation rail), `below` drops it under the button (Mountain View's top
+ * bar).
+ */
+export function NotificationBell({ placement, className }: { placement: "side" | "below"; className?: string }) {
+  const t = useTranslations("notification_center");
+  const unread = useUnreadNotificationCount();
+  const [open, setOpen] = useState(false);
+  const buttonRef = useRef<HTMLButtonElement>(null);
+  const panelRef = useRef<HTMLDivElement>(null);
+  const [style, setStyle] = useState<React.CSSProperties>({});
+  const close = useCallback(() => setOpen(false), []);
+
+  const position = useCallback(() => {
+    const rect = buttonRef.current?.getBoundingClientRect();
+    if (!rect) return;
+    if (placement === "side") {
+      const bottom = Math.max(8, window.innerHeight - rect.bottom);
+      setStyle(isDocumentRTL()
+        ? { position: "fixed", right: window.innerWidth - rect.left + 8, bottom }
+        : { position: "fixed", left: rect.right + 8, bottom });
+    } else {
+      const top = rect.bottom + 4;
+      setStyle(isDocumentRTL()
+        ? { position: "fixed", left: Math.max(8, rect.left), top }
+        : { position: "fixed", right: Math.max(8, window.innerWidth - rect.right), top });
+    }
+  }, [placement]);
+
+  useLayoutEffect(() => {
+    if (open) position();
+  }, [open, position]);
+
+  useEffect(() => {
+    if (!open) return;
+    const onPointerDown = (e: MouseEvent) => {
+      if (buttonRef.current?.contains(e.target as Node) || panelRef.current?.contains(e.target as Node)) return;
+      setOpen(false);
+    };
+    const onKeyDown = (e: KeyboardEvent) => {
+      if (e.key === "Escape") {
+        setOpen(false);
+        buttonRef.current?.focus();
+      }
+    };
+    document.addEventListener("mousedown", onPointerDown);
+    document.addEventListener("keydown", onKeyDown);
+    window.addEventListener("resize", position);
+    return () => {
+      document.removeEventListener("mousedown", onPointerDown);
+      document.removeEventListener("keydown", onKeyDown);
+      window.removeEventListener("resize", position);
+    };
+  }, [open, position]);
+
+  const label = unread > 0 ? `${t("title")} (${t("unread_count", { count: unread })})` : t("title");
+
+  return (
+    <>
+      <button
+        ref={buttonRef}
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        className={cn(
+          "relative grid place-items-center transition-colors",
+          open ? "bg-muted text-foreground" : "text-muted-foreground hover:bg-muted hover:text-foreground",
+          className,
+        )}
+        title={t("title")}
+        aria-label={label}
+        aria-haspopup="dialog"
+        aria-expanded={open}
+        data-notification-bell=""
+      >
+        <Bell className={placement === "side" ? "w-[18px] h-[18px]" : "w-5 h-5"} />
+        {unread > 0 && (
+          <span
+            className={cn(
+              "absolute flex items-center justify-center min-w-[16px] h-4 px-1 rounded-full bg-red-500 text-white text-[10px] font-bold",
+              placement === "side" ? "-top-0.5 -end-0.5" : "top-1.5 end-1.5",
+            )}
+            aria-hidden="true"
+          >
+            {formatBadgeCount(unread)}
+          </span>
+        )}
+      </button>
+      {open && createPortal(
+        <div
+          ref={panelRef}
+          role="dialog"
+          aria-label={t("title")}
+          style={style}
+          className="z-50 w-[22rem] max-w-[calc(100vw-1rem)] max-h-[min(32rem,80vh)] flex flex-col overflow-hidden rounded-lg border border-border bg-background shadow-lg"
+        >
+          <NotificationPanel onClose={close} className="flex-1 min-h-0" />
+        </div>,
+        document.body,
+      )}
+    </>
+  );
+}
diff --git a/lib/__tests__/plugin-host-notifications.test.ts b/lib/__tests__/plugin-host-notifications.test.ts
index 0d51cd103..c798f3737 100644
--- a/lib/__tests__/plugin-host-notifications.test.ts
+++ b/lib/__tests__/plugin-host-notifications.test.ts
@@ -113,3 +113,30 @@ describe('api.notifications.show', () => {
     expect(FakeNotification.shown[0].options.body).toBe('a b\nRSS Reader');
   });
 });
+
+describe('api.notifications.show in the notification panel', () => {
+  beforeEach(async () => {
+    const { useNotificationCenterStore } = await import('@/stores/notification-center-store');
+    useNotificationCenterStore.getState().clear();
+  });
+  const entries = async () => (await import('@/stores/notification-center-store')).useNotificationCenterStore.getState().entries;
+
+  it('lists each one with the plugin and its tag, shown as system notification or toast', async () => {
+    await call(RSS, { title: '3 new posts', body: 'From Hacker News', tag: 'feed:hn' });
+    FakeNotification.permission = 'default';
+    await call(RSS, { title: 'Synced' });
+
+    expect((await entries()).map((e) => [e.title, e.body, e.pluginId, e.pluginName, e.tag])).toEqual([
+      ['Synced', '', 'rss', 'RSS Reader', undefined],
+      ['3 new posts', 'From Hacker News', 'rss', 'RSS Reader', 'feed:hn'],
+    ]);
+  });
+
+  it('lists nothing the plugin was refused', async () => {
+    await expect(call(RSS, { title: 'ok', tag: 'has space' })).rejects.toThrow();
+    for (let i = 0; i < 5; i++) await call(RSS, { title: `n${i}` });
+    await expect(call(RSS, { title: 'too many' })).rejects.toThrow();
+    expect((await entries()).map((e) => e.title)).not.toContain('too many');
+    expect(await entries()).toHaveLength(5);
+  });
+});
diff --git a/lib/plugin-sandbox/host-api-notify.ts b/lib/plugin-sandbox/host-api-notify.ts
index a6cf4a6a1..df882a2a1 100644
--- a/lib/plugin-sandbox/host-api-notify.ts
+++ b/lib/plugin-sandbox/host-api-notify.ts
@@ -6,6 +6,7 @@ import type { InstalledPlugin, NotificationInput } from '../plugin-types';
 import { toast as appToast } from '@/stores/toast-store';
 import { toastHooks } from '../plugin-hooks';
 import { readObject, readString, withinRate } from './host-api-input';
+import { recordNotification } from '@/stores/notification-center-store';
 
 export const MAX_NOTIFICATION_TITLE = 120;
 export const MAX_NOTIFICATION_BODY = 300;
@@ -39,6 +40,9 @@ export function doNotificationsShow(plugin: InstalledPlugin, input: unknown): 's
   }
 
   const source = plugin.name || plugin.id;
+  // Also listed in the app's notification panel (the bell), where a click
+  // reaches the plugin the same way as a click on the system notification.
+  recordNotification({ level: 'info', title, body, pluginId: plugin.id, pluginName: source, ...(tag ? { tag } : {}) });
   if (typeof Notification !== 'undefined' && Notification.permission === 'granted') {
     try {
       const notification = new Notification(title, {
diff --git a/locales/ar/common.json b/locales/ar/common.json
index f48703e28..86e18cb38 100644
--- a/locales/ar/common.json
+++ b/locales/ar/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "الانتقال إلى",
     "group_actions": "إجراءات",
     "group_plugins": "الإضافات"
+  },
+  "notification_center": {
+    "title": "الإشعارات",
+    "mark_all_read": "تعليم الكل كمقروء",
+    "clear": "مسح",
+    "empty": "لا توجد إشعارات",
+    "close": "إغلاق",
+    "unread": "غير مقروء",
+    "unread_count": "غير المقروءة: {count}",
+    "level_error": "خطأ",
+    "level_warning": "تحذير"
   }
 }
diff --git a/locales/ca/common.json b/locales/ca/common.json
index b79cc2fc1..cc65b03f3 100644
--- a/locales/ca/common.json
+++ b/locales/ca/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Ves a",
     "group_actions": "Accions",
     "group_plugins": "Connectors"
+  },
+  "notification_center": {
+    "title": "Notificacions",
+    "mark_all_read": "Marca-ho tot com a llegit",
+    "clear": "Esborra",
+    "empty": "No hi ha notificacions",
+    "close": "Tanca",
+    "unread": "No llegida",
+    "unread_count": "{count} sense llegir",
+    "level_error": "Error",
+    "level_warning": "Avís"
   }
 }
diff --git a/locales/cs/common.json b/locales/cs/common.json
index 97d070dcd..edfec1d50 100644
--- a/locales/cs/common.json
+++ b/locales/cs/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Přejít na",
     "group_actions": "Akce",
     "group_plugins": "Pluginy"
+  },
+  "notification_center": {
+    "title": "Oznámení",
+    "mark_all_read": "Označit vše jako přečtené",
+    "clear": "Vymazat",
+    "empty": "Žádná oznámení",
+    "close": "Zavřít",
+    "unread": "Nepřečtené",
+    "unread_count": "Nepřečtené: {count}",
+    "level_error": "Chyba",
+    "level_warning": "Upozornění"
   }
 }
diff --git a/locales/da/common.json b/locales/da/common.json
index 362f80467..f21bc61c1 100644
--- a/locales/da/common.json
+++ b/locales/da/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Gå til",
     "group_actions": "Handlinger",
     "group_plugins": "Plugins"
+  },
+  "notification_center": {
+    "title": "Notifikationer",
+    "mark_all_read": "Markér alle som læst",
+    "clear": "Ryd",
+    "empty": "Ingen notifikationer",
+    "close": "Luk",
+    "unread": "Ulæst",
+    "unread_count": "{count} ulæste",
+    "level_error": "Fejl",
+    "level_warning": "Advarsel"
   }
 }
diff --git a/locales/de/common.json b/locales/de/common.json
index 997d4e2a0..3fc12b853 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Wechseln zu",
     "group_actions": "Aktionen",
     "group_plugins": "Plugins"
+  },
+  "notification_center": {
+    "title": "Benachrichtigungen",
+    "mark_all_read": "Alle als gelesen markieren",
+    "clear": "Leeren",
+    "empty": "Keine Benachrichtigungen",
+    "close": "Schließen",
+    "unread": "Ungelesen",
+    "unread_count": "{count} ungelesen",
+    "level_error": "Fehler",
+    "level_warning": "Warnung"
   }
 }
diff --git a/locales/en/common.json b/locales/en/common.json
index 169125524..7ad0bd579 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Go to",
     "group_actions": "Actions",
     "group_plugins": "Plugins"
+  },
+  "notification_center": {
+    "title": "Notifications",
+    "mark_all_read": "Mark all read",
+    "clear": "Clear",
+    "empty": "No notifications",
+    "close": "Close",
+    "unread": "Unread",
+    "unread_count": "{count} unread",
+    "level_error": "Error",
+    "level_warning": "Warning"
   }
 }
diff --git a/locales/es/common.json b/locales/es/common.json
index e47767b5a..7a11b880b 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Ir a",
     "group_actions": "Acciones",
     "group_plugins": "Complementos"
+  },
+  "notification_center": {
+    "title": "Notificaciones",
+    "mark_all_read": "Marcar todo como leído",
+    "clear": "Borrar",
+    "empty": "No hay notificaciones",
+    "close": "Cerrar",
+    "unread": "Sin leer",
+    "unread_count": "{count} sin leer",
+    "level_error": "Error",
+    "level_warning": "Advertencia"
   }
 }
diff --git a/locales/fa/common.json b/locales/fa/common.json
index dca1b790a..e23fe3ef2 100644
--- a/locales/fa/common.json
+++ b/locales/fa/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "رفتن به",
     "group_actions": "کارها",
     "group_plugins": "افزونه‌ها"
+  },
+  "notification_center": {
+    "title": "اعلان‌ها",
+    "mark_all_read": "علامت‌گذاری همه به‌عنوان خوانده‌شده",
+    "clear": "پاک کردن",
+    "empty": "اعلانی نیست",
+    "close": "بستن",
+    "unread": "خوانده‌نشده",
+    "unread_count": "{count} خوانده‌نشده",
+    "level_error": "خطا",
+    "level_warning": "هشدار"
   }
 }
diff --git a/locales/fr/common.json b/locales/fr/common.json
index 0134c04fd..915ce2f4b 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Aller à",
     "group_actions": "Actions",
     "group_plugins": "Plugins"
+  },
+  "notification_center": {
+    "title": "Notifications",
+    "mark_all_read": "Tout marquer comme lu",
+    "clear": "Effacer",
+    "empty": "Aucune notification",
+    "close": "Fermer",
+    "unread": "Non lu",
+    "unread_count": "Non lues : {count}",
+    "level_error": "Erreur",
+    "level_warning": "Avertissement"
   }
 }
diff --git a/locales/he/common.json b/locales/he/common.json
index b3b103e50..75c53dd8b 100644
--- a/locales/he/common.json
+++ b/locales/he/common.json
@@ -4366,5 +4366,16 @@
     "group_navigation": "מעבר אל",
     "group_actions": "פעולות",
     "group_plugins": "תוספים"
+  },
+  "notification_center": {
+    "title": "התראות",
+    "mark_all_read": "סימון הכול כנקרא",
+    "clear": "ניקוי",
+    "empty": "אין התראות",
+    "close": "סגירה",
+    "unread": "לא נקרא",
+    "unread_count": "לא נקראו: {count}",
+    "level_error": "שגיאה",
+    "level_warning": "אזהרה"
   }
 }
diff --git a/locales/hu/common.json b/locales/hu/common.json
index 40b016251..8b493a44a 100644
--- a/locales/hu/common.json
+++ b/locales/hu/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Ugrás ide",
     "group_actions": "Műveletek",
     "group_plugins": "Bővítmények"
+  },
+  "notification_center": {
+    "title": "Értesítések",
+    "mark_all_read": "Összes megjelölése olvasottként",
+    "clear": "Törlés",
+    "empty": "Nincsenek értesítések",
+    "close": "Bezárás",
+    "unread": "Olvasatlan",
+    "unread_count": "{count} olvasatlan",
+    "level_error": "Hiba",
+    "level_warning": "Figyelmeztetés"
   }
 }
diff --git a/locales/it/common.json b/locales/it/common.json
index 35edc4398..6678918a0 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Vai a",
     "group_actions": "Azioni",
     "group_plugins": "Plugin"
+  },
+  "notification_center": {
+    "title": "Notifiche",
+    "mark_all_read": "Segna tutte come lette",
+    "clear": "Cancella",
+    "empty": "Nessuna notifica",
+    "close": "Chiudi",
+    "unread": "Non letta",
+    "unread_count": "{count} non lette",
+    "level_error": "Errore",
+    "level_warning": "Avviso"
   }
 }
diff --git a/locales/ja/common.json b/locales/ja/common.json
index 053c04031..1ad2be5f2 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "移動",
     "group_actions": "操作",
     "group_plugins": "プラグイン"
+  },
+  "notification_center": {
+    "title": "通知",
+    "mark_all_read": "すべて既読にする",
+    "clear": "クリア",
+    "empty": "通知はありません",
+    "close": "閉じる",
+    "unread": "未読",
+    "unread_count": "未読 {count} 件",
+    "level_error": "エラー",
+    "level_warning": "警告"
   }
 }
diff --git a/locales/ko/common.json b/locales/ko/common.json
index 643bb7558..46a634941 100644
--- a/locales/ko/common.json
+++ b/locales/ko/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "이동",
     "group_actions": "작업",
     "group_plugins": "플러그인"
+  },
+  "notification_center": {
+    "title": "알림",
+    "mark_all_read": "모두 읽음으로 표시",
+    "clear": "지우기",
+    "empty": "알림이 없습니다",
+    "close": "닫기",
+    "unread": "읽지 않음",
+    "unread_count": "읽지 않음 {count}개",
+    "level_error": "오류",
+    "level_warning": "경고"
   }
 }
diff --git a/locales/lv/common.json b/locales/lv/common.json
index e2cb18184..11bab0506 100644
--- a/locales/lv/common.json
+++ b/locales/lv/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Pāriet uz",
     "group_actions": "Darbības",
     "group_plugins": "Spraudņi"
+  },
+  "notification_center": {
+    "title": "Paziņojumi",
+    "mark_all_read": "Atzīmēt visus kā lasītus",
+    "clear": "Notīrīt",
+    "empty": "Nav paziņojumu",
+    "close": "Aizvērt",
+    "unread": "Nelasīts",
+    "unread_count": "Nelasīti: {count}",
+    "level_error": "Kļūda",
+    "level_warning": "Brīdinājums"
   }
 }
diff --git a/locales/mn/common.json b/locales/mn/common.json
index b4e7e9f92..65570d59b 100644
--- a/locales/mn/common.json
+++ b/locales/mn/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Очих",
     "group_actions": "Үйлдлүүд",
     "group_plugins": "Залгаасууд"
+  },
+  "notification_center": {
+    "title": "Мэдэгдэл",
+    "mark_all_read": "Бүгдийг уншсан болгох",
+    "clear": "Цэвэрлэх",
+    "empty": "Мэдэгдэл алга",
+    "close": "Хаах",
+    "unread": "Уншаагүй",
+    "unread_count": "Уншаагүй: {count}",
+    "level_error": "Алдаа",
+    "level_warning": "Анхааруулга"
   }
 }
diff --git a/locales/nb/common.json b/locales/nb/common.json
index c1ff00c11..f8ce92b63 100644
--- a/locales/nb/common.json
+++ b/locales/nb/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Gå til",
     "group_actions": "Handlinger",
     "group_plugins": "Tillegg"
+  },
+  "notification_center": {
+    "title": "Varsler",
+    "mark_all_read": "Merk alle som lest",
+    "clear": "Tøm",
+    "empty": "Ingen varsler",
+    "close": "Lukk",
+    "unread": "Ulest",
+    "unread_count": "{count} uleste",
+    "level_error": "Feil",
+    "level_warning": "Advarsel"
   }
 }
diff --git a/locales/nl/common.json b/locales/nl/common.json
index 4596218a5..8ee8a40be 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Naar",
     "group_actions": "Acties",
     "group_plugins": "Plug-ins"
+  },
+  "notification_center": {
+    "title": "Meldingen",
+    "mark_all_read": "Alles als gelezen markeren",
+    "clear": "Wissen",
+    "empty": "Geen meldingen",
+    "close": "Sluiten",
+    "unread": "Ongelezen",
+    "unread_count": "{count} ongelezen",
+    "level_error": "Fout",
+    "level_warning": "Waarschuwing"
   }
 }
diff --git a/locales/pl/common.json b/locales/pl/common.json
index c38cf8627..fd572eff5 100644
--- a/locales/pl/common.json
+++ b/locales/pl/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Przejdź do",
     "group_actions": "Działania",
     "group_plugins": "Wtyczki"
+  },
+  "notification_center": {
+    "title": "Powiadomienia",
+    "mark_all_read": "Oznacz wszystkie jako przeczytane",
+    "clear": "Wyczyść",
+    "empty": "Brak powiadomień",
+    "close": "Zamknij",
+    "unread": "Nieprzeczytane",
+    "unread_count": "Nieprzeczytane: {count}",
+    "level_error": "Błąd",
+    "level_warning": "Ostrzeżenie"
   }
 }
diff --git a/locales/pt/common.json b/locales/pt/common.json
index 7642d9559..b13c01779 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Ir para",
     "group_actions": "Ações",
     "group_plugins": "Plugins"
+  },
+  "notification_center": {
+    "title": "Notificações",
+    "mark_all_read": "Marcar todas como lidas",
+    "clear": "Limpar",
+    "empty": "Nenhuma notificação",
+    "close": "Fechar",
+    "unread": "Não lida",
+    "unread_count": "{count} não lidas",
+    "level_error": "Erro",
+    "level_warning": "Aviso"
   }
 }
diff --git a/locales/ro/common.json b/locales/ro/common.json
index 9dfb217b9..80795a2a7 100644
--- a/locales/ro/common.json
+++ b/locales/ro/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Mergi la",
     "group_actions": "Acțiuni",
     "group_plugins": "Pluginuri"
+  },
+  "notification_center": {
+    "title": "Notificări",
+    "mark_all_read": "Marchează toate ca citite",
+    "clear": "Golește",
+    "empty": "Nicio notificare",
+    "close": "Închide",
+    "unread": "Necitită",
+    "unread_count": "Necitite: {count}",
+    "level_error": "Eroare",
+    "level_warning": "Avertisment"
   }
 }
diff --git a/locales/ru/common.json b/locales/ru/common.json
index 86468538d..814b251a1 100644
--- a/locales/ru/common.json
+++ b/locales/ru/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Перейти",
     "group_actions": "Действия",
     "group_plugins": "Плагины"
+  },
+  "notification_center": {
+    "title": "Уведомления",
+    "mark_all_read": "Отметить все как прочитанные",
+    "clear": "Очистить",
+    "empty": "Нет уведомлений",
+    "close": "Закрыть",
+    "unread": "Непрочитанное",
+    "unread_count": "Непрочитанных: {count}",
+    "level_error": "Ошибка",
+    "level_warning": "Предупреждение"
   }
 }
diff --git a/locales/sk/common.json b/locales/sk/common.json
index 08666a759..81981ea8a 100644
--- a/locales/sk/common.json
+++ b/locales/sk/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Prejsť na",
     "group_actions": "Akcie",
     "group_plugins": "Doplnky"
+  },
+  "notification_center": {
+    "title": "Oznámenia",
+    "mark_all_read": "Označiť všetko ako prečítané",
+    "clear": "Vymazať",
+    "empty": "Žiadne oznámenia",
+    "close": "Zavrieť",
+    "unread": "Neprečítané",
+    "unread_count": "Neprečítané: {count}",
+    "level_error": "Chyba",
+    "level_warning": "Varovanie"
   }
 }
diff --git a/locales/tr/common.json b/locales/tr/common.json
index 4d5180fbd..240e95fba 100644
--- a/locales/tr/common.json
+++ b/locales/tr/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Git",
     "group_actions": "Eylemler",
     "group_plugins": "Eklentiler"
+  },
+  "notification_center": {
+    "title": "Bildirimler",
+    "mark_all_read": "Tümünü okundu işaretle",
+    "clear": "Temizle",
+    "empty": "Bildirim yok",
+    "close": "Kapat",
+    "unread": "Okunmamış",
+    "unread_count": "{count} okunmamış",
+    "level_error": "Hata",
+    "level_warning": "Uyarı"
   }
 }
diff --git a/locales/uk/common.json b/locales/uk/common.json
index 321128785..e9c9875ec 100644
--- a/locales/uk/common.json
+++ b/locales/uk/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "Перейти",
     "group_actions": "Дії",
     "group_plugins": "Плагіни"
+  },
+  "notification_center": {
+    "title": "Сповіщення",
+    "mark_all_read": "Позначити всі як прочитані",
+    "clear": "Очистити",
+    "empty": "Немає сповіщень",
+    "close": "Закрити",
+    "unread": "Непрочитане",
+    "unread_count": "Непрочитаних: {count}",
+    "level_error": "Помилка",
+    "level_warning": "Попередження"
   }
 }
diff --git a/locales/zh-TW/common.json b/locales/zh-TW/common.json
index 66991e896..e6dc964f7 100644
--- a/locales/zh-TW/common.json
+++ b/locales/zh-TW/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "前往",
     "group_actions": "動作",
     "group_plugins": "外掛程式"
+  },
+  "notification_center": {
+    "title": "通知",
+    "mark_all_read": "全部標示為已讀",
+    "clear": "清除",
+    "empty": "沒有通知",
+    "close": "關閉",
+    "unread": "未讀",
+    "unread_count": "{count} 則未讀",
+    "level_error": "錯誤",
+    "level_warning": "警告"
   }
 }
diff --git a/locales/zh/common.json b/locales/zh/common.json
index dea411efc..3884bfb03 100644
--- a/locales/zh/common.json
+++ b/locales/zh/common.json
@@ -4365,5 +4365,16 @@
     "group_navigation": "前往",
     "group_actions": "操作",
     "group_plugins": "插件"
+  },
+  "notification_center": {
+    "title": "通知",
+    "mark_all_read": "全部标为已读",
+    "clear": "清除",
+    "empty": "没有通知",
+    "close": "关闭",
+    "unread": "未读",
+    "unread_count": "{count} 条未读",
+    "level_error": "错误",
+    "level_warning": "警告"
   }
 }
diff --git a/stores/__tests__/notification-center-store.test.ts b/stores/__tests__/notification-center-store.test.ts
new file mode 100644
index 000000000..7dcb96087
--- /dev/null
+++ b/stores/__tests__/notification-center-store.test.ts
@@ -0,0 +1,70 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import {
+  MAX_ENTRIES,
+  reloadNotificationCenter,
+  selectUnreadCount,
+  useNotificationCenterStore,
+} from '../notification-center-store';
+import { toast } from '../toast-store';
+
+const store = () => useNotificationCenterStore.getState();
+
+beforeEach(() => {
+  localStorage.clear();
+  store().clear();
+});
+afterEach(() => vi.restoreAllMocks());
+
+describe('notification center', () => {
+  it('keeps the newest first and only the last 50', () => {
+    for (let i = 0; i < MAX_ENTRIES + 5; i++) store().add({ level: 'info', title: `n${i}`, body: '' });
+    expect(store().entries).toHaveLength(MAX_ENTRIES);
+    expect(store().entries[0].title).toBe(`n${MAX_ENTRIES + 4}`);
+    expect(store().entries.at(-1)!.title).toBe('n5');
+  });
+
+  it('survives a reload of the page', () => {
+    store().add({ level: 'info', title: 'From the plugin', body: 'b', pluginId: 'rss', pluginName: 'RSS', tag: 't1' });
+    useNotificationCenterStore.setState({ entries: [] });
+    reloadNotificationCenter();
+    expect(store().entries).toMatchObject([{ title: 'From the plugin', pluginId: 'rss', pluginName: 'RSS', tag: 't1', read: false }]);
+  });
+
+  it('counts unread, marks all read and clears', () => {
+    store().add({ level: 'error', title: 'a', body: '' });
+    store().add({ level: 'warning', title: 'b', body: '' });
+    expect(selectUnreadCount(store())).toBe(2);
+    store().markAllRead();
+    expect(selectUnreadCount(store())).toBe(0);
+    reloadNotificationCenter();
+    expect(selectUnreadCount(store())).toBe(0);
+    store().clear();
+    reloadNotificationCenter();
+    expect(store().entries).toEqual([]);
+  });
+
+  it('works without storage', () => {
+    vi.spyOn(Storage.prototype, 'setItem').mockImplementation(() => { throw new Error('blocked'); });
+    vi.spyOn(localStorage, 'setItem').mockImplementation(() => { throw new Error('blocked'); });
+    expect(() => store().add({ level: 'info', title: 'x', body: '' })).not.toThrow();
+    expect(store().entries).toHaveLength(1);
+  });
+
+  it('drops malformed stored entries', () => {
+    localStorage.setItem('notification-center', JSON.stringify([{ id: 1 }, 'x', { id: 'a', time: 1, title: 't', body: '', read: false, level: 'info' }]));
+    reloadNotificationCenter();
+    expect(store().entries.map((e) => e.id)).toEqual(['a']);
+  });
+
+  it('records the app\'s error and warning toasts, not the others', () => {
+    toast.error('Could not send', 'Server said no');
+    toast.warning('Quota almost full');
+    toast.success('Sent');
+    toast.info('Heads up');
+    expect(store().entries.map((e) => [e.level, e.title, e.body])).toEqual([
+      ['warning', 'Quota almost full', ''],
+      ['error', 'Could not send', 'Server said no'],
+    ]);
+    expect(store().entries[0].pluginId).toBeUndefined();
+  });
+});
diff --git a/stores/notification-center-store.ts b/stores/notification-center-store.ts
new file mode 100644
index 000000000..4491f8461
--- /dev/null
+++ b/stores/notification-center-store.ts
@@ -0,0 +1,114 @@
+import { create } from 'zustand';
+import { generateUUID } from '@/lib/utils';
+
+// The in-app notification list behind the bell: what plugins showed with
+// api.notifications.show and the app's own error and warning toasts. Kept in
+// this browser only (localStorage), the last MAX_ENTRIES of them.
+
+export const MAX_ENTRIES = 50;
+const STORAGE_KEY = 'notification-center';
+
+export interface CenterEntry {
+  id: string;
+  /** Unix ms. */
+  time: number;
+  level: 'error' | 'warning' | 'info';
+  title: string;
+  body: string;
+  /** Set for plugin notifications: whose they are, and the tag the plugin passed. */
+  pluginId?: string;
+  pluginName?: string;
+  tag?: string;
+  read: boolean;
+}
+
+export type CenterEntryInput = Omit<CenterEntry, 'id' | 'time' | 'read'> & { time?: number };
+
+interface NotificationCenterState {
+  entries: CenterEntry[];
+  add: (input: CenterEntryInput) => void;
+  markRead: (id: string) => void;
+  markAllRead: () => void;
+  clear: () => void;
+}
+
+function isEntry(value: unknown): value is CenterEntry {
+  if (!value || typeof value !== 'object') return false;
+  const e = value as Record<string, unknown>;
+  return typeof e.id === 'string' && typeof e.time === 'number' && typeof e.title === 'string'
+    && typeof e.body === 'string' && typeof e.read === 'boolean'
+    && (e.level === 'error' || e.level === 'warning' || e.level === 'info');
+}
+
+function load(): CenterEntry[] {
+  try {
+    const raw = typeof localStorage !== 'undefined' ? localStorage.getItem(STORAGE_KEY) : null;
+    if (!raw) return [];
+    const parsed: unknown = JSON.parse(raw);
+    return Array.isArray(parsed) ? parsed.filter(isEntry).slice(0, MAX_ENTRIES) : [];
+  } catch {
+    return [];
+  }
+}
+
+function save(entries: CenterEntry[]): void {
+  try {
+    if (entries.length === 0) localStorage.removeItem(STORAGE_KEY);
+    else localStorage.setItem(STORAGE_KEY, JSON.stringify(entries));
+  } catch {
+    // Storage blocked or full: the list still works for this page load.
+  }
+}
+
+export const useNotificationCenterStore = create<NotificationCenterState>((set, get) => ({
+  entries: load(),
+
+  add: (input) => {
+    const entry: CenterEntry = {
+      id: generateUUID(),
+      time: input.time ?? Date.now(),
+      level: input.level,
+      title: input.title,
+      body: input.body,
+      ...(input.pluginId ? { pluginId: input.pluginId, pluginName: input.pluginName ?? input.pluginId } : {}),
+      ...(input.tag ? { tag: input.tag } : {}),
+      read: false,
+    };
+    const entries = [entry, ...get().entries].slice(0, MAX_ENTRIES);
+    set({ entries });
+    save(entries);
+  },
+
+  markRead: (id) => {
+    const entries = get().entries.map((e) => (e.id === id && !e.read ? { ...e, read: true } : e));
+    set({ entries });
+    save(entries);
+  },
+
+  markAllRead: () => {
+    const entries = get().entries.map((e) => (e.read ? e : { ...e, read: true }));
+    set({ entries });
+    save(entries);
+  },
+
+  clear: () => {
+    set({ entries: [] });
+    save([]);
+  },
+}));
+
+export const selectUnreadCount = (s: NotificationCenterState) => s.entries.reduce((n, e) => n + (e.read ? 0 : 1), 0);
+
+/** Add an entry from outside React (toast store, plugin host API). */
+export function recordNotification(input: CenterEntryInput): void {
+  try {
+    useNotificationCenterStore.getState().add(input);
+  } catch {
+    // Never let the list break the thing that is being reported.
+  }
+}
+
+/** Test helper: read the list back from storage as a fresh page load would. */
+export function reloadNotificationCenter(): void {
+  useNotificationCenterStore.setState({ entries: load() });
+}
diff --git a/stores/toast-store.ts b/stores/toast-store.ts
index 8c114c3c4..682d1e34f 100644
--- a/stores/toast-store.ts
+++ b/stores/toast-store.ts
@@ -2,6 +2,7 @@ import { create } from "zustand";
 import { Toast, ToastAction } from "@/components/ui/toast";
 import { generateUUID } from "@/lib/utils";
 import { toastHooks } from "@/lib/plugin-hooks";
+import { recordNotification } from "@/stores/notification-center-store";
 
 interface ToastStore {
   toasts: Toast[];
@@ -33,6 +34,10 @@ export const useToastStore = create<ToastStore>((set, get) => ({
     void toastHooks.onToastShow.emit({
       id, type: toast.type, title: toast.title, message: toast.message ?? "",
     });
+    // Errors and warnings stay in the bell's list after the toast is gone.
+    if (toast.type === "error" || toast.type === "warning") {
+      recordNotification({ level: toast.type, title: toast.title, body: toast.message ?? "" });
+    }
     return id;
   },