diff --git a/apps/desktop/src/app/desktop-controller.tsx b/apps/desktop/src/app/desktop-controller.tsx
index c2523bf3654..5ca73061135 100644
--- a/apps/desktop/src/app/desktop-controller.tsx
+++ b/apps/desktop/src/app/desktop-controller.tsx
@@ -14,13 +14,13 @@ import { useSkinCommand } from '@/themes/use-skin-command'
 import { formatRefValue } from '../components/assistant-ui/directive-text'
 import { getCronJobs, getSessionMessages, listAllProfileSessions, type SessionInfo, triggerCronJob } from '../hermes'
 import { type ChatMessage, chatMessageText, preserveLocalAssistantErrors, toChatMessages } from '../lib/chat-messages'
+import { storedSessionIdForNotification } from '../lib/session-ids'
 import {
   isMessagingSource,
   LOCAL_SESSION_SOURCE_IDS,
   MESSAGING_SESSION_SOURCE_IDS,
   normalizeSessionSource
 } from '../lib/session-source'
-import { storedSessionIdForNotification } from '../lib/session-ids'
 import { latestSessionTodos } from '../lib/todos'
 import { setCronFocusJobId, setCronJobs } from '../store/cron'
 import {
diff --git a/apps/desktop/src/lib/session-ids.test.ts b/apps/desktop/src/lib/session-ids.test.ts
new file mode 100644
index 00000000000..b5653c8eecd
--- /dev/null
+++ b/apps/desktop/src/lib/session-ids.test.ts
@@ -0,0 +1,44 @@
+import { describe, expect, it } from 'vitest'
+
+import { storedSessionIdForNotification } from './session-ids'
+
+describe('storedSessionIdForNotification', () => {
+  it('translates a runtime id back to its stored id', () => {
+    // The route is keyed by the stored id, but notifications carry the runtime
+    // id. Resolving runtime -> stored keeps notification-click navigation from
+    // resuming a non-existent stored session ("session not found").
+    const map = new Map([['stored-abc', 'runtime-123']])
+
+    expect(storedSessionIdForNotification('runtime-123', map)).toBe('stored-abc')
+  })
+
+  it('returns the id unchanged when no mapping is known', () => {
+    // A notification for a session this window never opened may already carry a
+    // stored id; let the resume/REST lookup handle it as-is.
+    const map = new Map([['stored-abc', 'runtime-123']])
+
+    expect(storedSessionIdForNotification('stored-xyz', map)).toBe('stored-xyz')
+  })
+
+  it('returns the id unchanged for an empty map', () => {
+    expect(storedSessionIdForNotification('runtime-123', new Map())).toBe('runtime-123')
+  })
+
+  it('resolves the correct stored id among several sessions', () => {
+    const map = new Map([
+      ['stored-1', 'runtime-1'],
+      ['stored-2', 'runtime-2'],
+      ['stored-3', 'runtime-3']
+    ])
+
+    expect(storedSessionIdForNotification('runtime-2', map)).toBe('stored-2')
+  })
+
+  it('does not treat a stored id as a runtime id (keys are not matched)', () => {
+    // The map is stored -> runtime. A value that only appears as a *key* must
+    // not be rewritten, otherwise an already-stored id could be mangled.
+    const map = new Map([['stored-1', 'runtime-1']])
+
+    expect(storedSessionIdForNotification('stored-1', map)).toBe('stored-1')
+  })
+})