diff --git a/apps/web/src/components/settings/desktop-app-settings.test.tsx b/apps/web/src/components/settings/desktop-app-settings.test.tsx
index 0cdd742..9c3b846 100644
--- a/apps/web/src/components/settings/desktop-app-settings.test.tsx
+++ b/apps/web/src/components/settings/desktop-app-settings.test.tsx
@@ -1,5 +1,6 @@
-import { cleanup, render, screen } from '@testing-library/react';
+import { act, cleanup, render, screen } from '@testing-library/react';
 import { afterEach, describe, expect, it, vi } from 'vitest';
+import { DESKTOP_COOKIE_NAME } from '@/lib/desktop-client';
 import { DesktopAppSettings } from './desktop-app-settings';
 
 /**
@@ -34,9 +35,14 @@ vi.mock('@/lib/desktop', async (importOriginal) => {
   };
 });
 
+function clearDesktopCookie() {
+  document.cookie = `${DESKTOP_COOKIE_NAME}=; expires=Thu, 01 Jan 1970 00:00:00 GMT; path=/`;
+}
+
 afterEach(() => {
   cleanup();
   vi.clearAllMocks();
+  clearDesktopCookie();
 });
 
 const windowsFile = {
@@ -102,4 +108,24 @@ describe('DesktopAppSettings (18-03)', () => {
       ),
     ).toBeInTheDocument();
   });
+
+  it('Test 4 (im Desktop-Client): zeigt verbundenen Server und Änderungshinweis', async () => {
+    document.cookie = `${DESKTOP_COOKIE_NAME}=1; path=/`;
+    loadDesktopLatest.mockResolvedValue(null);
+    render(<DesktopAppSettings />);
+
+    expect(await screen.findByText('Verbunden mit: http://localhost:3000')).toBeInTheDocument();
+    expect(
+      screen.getByText('Ändern über das Tessera-Symbol im Infobereich → „Server-Adresse ändern…“'),
+    ).toBeInTheDocument();
+    expect(screen.getByTestId('desktop-connected')).toBeInTheDocument();
+  });
+
+  it('Test 5 (im Browser): kein Block ohne Desktop-Cookie', async () => {
+    loadDesktopLatest.mockResolvedValue(null);
+    render(<DesktopAppSettings />);
+    await act(async () => {});
+
+    expect(screen.queryByTestId('desktop-connected')).toBeNull();
+  });
 });
diff --git a/apps/web/src/components/settings/desktop-app-settings.tsx b/apps/web/src/components/settings/desktop-app-settings.tsx
index 7726d97..491d654 100644
--- a/apps/web/src/components/settings/desktop-app-settings.tsx
+++ b/apps/web/src/components/settings/desktop-app-settings.tsx
@@ -3,6 +3,7 @@
 import { useEffect, useState } from 'react';
 import { useLocale, useTranslations } from 'next-intl';
 import { desktopDownloadUrl, type DesktopFileInfo, type DesktopLatestInfo, formatFileSize, loadDesktopLatest } from '@/lib/desktop';
+import { useIsDesktopClient } from '@/lib/desktop-client';
 
 const BUTTON_CLASS =
   'inline-flex items-center gap-2 rounded-md bg-primary px-4 py-2.5 text-sm font-medium text-primary-foreground hover:opacity-90';
@@ -59,11 +60,17 @@ function DownloadButton({
 /**
  * Inhalt der Einstellungsseite "Desktop-App" (D-12): vier erklaerende
  * Saetze, dann Version/Downloads oder ein Hinweis, wenn der Server keine
- * Pakete traegt (`loadDesktopLatest()` liefert `null`).
+ * Pakete traegt (`loadDesktopLatest()` liefert `null`). Im Desktop-Client
+ * (260917-jn2) zusaetzlich ein Block "Verbunden mit: {origin}" -- `isDesktop`
+ * ist im Server-HTML und im ersten Client-Render false (Hook mit
+ * `useEffect`), der Block rendert also erst nach der Hydration, weshalb
+ * `window.location.origin` hier direkt gelesen werden darf (kein
+ * Hydration-Fehler).
  */
 export function DesktopAppSettings() {
   const t = useTranslations('settings');
   const locale = useLocale();
+  const isDesktop = useIsDesktopClient();
   const [info, setInfo] = useState<DesktopLatestInfo | null | undefined>(undefined);
 
   useEffect(() => {
@@ -85,6 +92,16 @@ export function DesktopAppSettings() {
       <p className="text-sm text-muted-foreground">{t('desktop.tray')}</p>
       <p className="text-sm text-muted-foreground">{t('desktop.update')}</p>
 
+      {isDesktop && (
+        <div
+          data-testid="desktop-connected"
+          className="mt-4 space-y-1 rounded border border-border bg-muted/30 p-3 text-sm"
+        >
+          <p className="text-foreground">{t('desktop.connectedTo', { origin: window.location.origin })}</p>
+          <p className="text-muted-foreground">{t('desktop.changeHint')}</p>
+        </div>
+      )}
+
       {info === null && <p className="mt-4 text-sm text-muted-foreground">{t('desktop.unavailable')}</p>}
 
       {info && (
diff --git a/apps/web/src/messages/de.json b/apps/web/src/messages/de.json
index 88d73e9..a7b88e6 100644
--- a/apps/web/src/messages/de.json
+++ b/apps/web/src/messages/de.json
@@ -169,7 +169,9 @@
       "downloadWindows": "Für Windows herunterladen",
       "downloadLinux": "Für Linux herunterladen",
       "fileInfo": "{name} · {size}",
-      "unavailable": "Auf diesem Server sind derzeit keine Desktop-Pakete hinterlegt."
+      "unavailable": "Auf diesem Server sind derzeit keine Desktop-Pakete hinterlegt.",
+      "connectedTo": "Verbunden mit: {origin}",
+      "changeHint": "Ändern über das Tessera-Symbol im Infobereich → „Server-Adresse ändern…“"
     },
     "sourceDeleteConfirm": "Möchten Sie diese Kalenderquelle wirklich löschen?",
     "sourceDeleteCta": "Quelle löschen",
diff --git a/apps/web/src/messages/en.json b/apps/web/src/messages/en.json
index 86fbd3e..96d909d 100644
--- a/apps/web/src/messages/en.json
+++ b/apps/web/src/messages/en.json
@@ -169,7 +169,9 @@
       "downloadWindows": "Download for Windows",
       "downloadLinux": "Download for Linux",
       "fileInfo": "{name} · {size}",
-      "unavailable": "No desktop packages are available on this server yet."
+      "unavailable": "No desktop packages are available on this server yet.",
+      "connectedTo": "Connected to: {origin}",
+      "changeHint": "To change it, use the Tessera icon in the notification area → “Change server address…”"
     },
     "sourceDeleteConfirm": "Are you sure you want to delete this calendar source?",
     "sourceDeleteCta": "Delete source",