fix(web): keep global SSE alive for session list status updates (#694)

When a session is open, the web app now keeps an always-on all:true SSE
connection for sidebar session-updated events while using a second
session-scoped stream for message delivery. Also bump session activity on
hub sendMessage so web-originated sends refresh list timestamps.

Fixes #693

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: heavygee

hub/src/sync/syncEngine.ts

@@ -364,6 +364,7 @@ export class SyncEngine {
     ): Promise<void> {
         await this.messageService.sendMessage(sessionId, payload)
         this.sessionCache.markMessageQueued(sessionId)
+        this.sessionCache.recordSessionActivity(sessionId, Date.now())
     }
 
     async cancelQueuedMessage(

web/src/App.tsx

@@ -19,6 +19,7 @@ import { useAppGoBack } from '@/hooks/useAppGoBack'
 import { useTranslation } from '@/lib/use-translation'
 import { VoiceProvider } from '@/lib/voice-context'
 import { requireHubUrlForLogin } from '@/lib/runtime-config'
+import { getAppGlobalSseSubscription, getAppSessionSseSubscription } from '@/lib/appSseSubscriptions'
 import { LoginPrompt } from '@/components/LoginPrompt'
 import { InstallPrompt } from '@/components/InstallPrompt'
 import { OfflineBanner } from '@/components/OfflineBanner'
@@ -295,28 +296,44 @@ function AppInner() {
         })
     }, [addToast, translateIncomingToast])
 
-    const eventSubscription = useMemo(() => {
-        if (selectedSessionId) {
-            return { sessionId: selectedSessionId }
-        }
-        return { all: true }
-    }, [selectedSessionId])
+    const globalEventSubscription = useMemo(() => getAppGlobalSseSubscription(), [])
+    const sessionEventSubscription = useMemo(
+        () => getAppSessionSseSubscription(selectedSessionId),
+        [selectedSessionId]
+    )
+    const sseEnabled = Boolean(api && token)
 
-    const { subscriptionId } = useSSE({
-        enabled: Boolean(api && token),
+    const { subscriptionId: globalSubscriptionId } = useSSE({
+        enabled: sseEnabled,
         token: token ?? '',
         baseUrl,
-        subscription: eventSubscription,
+        subscription: globalEventSubscription,
+        scope: 'global',
         onConnect: handleSseConnect,
         onDisconnect: handleSseDisconnect,
-        onEvent: handleSseEvent,
+        onEvent: () => {},
         onToast: handleToast
     })
 
+    const { subscriptionId: sessionSubscriptionId } = useSSE({
+        enabled: sseEnabled && Boolean(sessionEventSubscription),
+        token: token ?? '',
+        baseUrl,
+        subscription: sessionEventSubscription ?? undefined,
+        scope: 'full',
+        onEvent: handleSseEvent
+    })
+
+    useVisibilityReporter({
+        api,
+        subscriptionId: globalSubscriptionId,
+        enabled: sseEnabled
+    })
+
     useVisibilityReporter({
         api,
-        subscriptionId,
-        enabled: Boolean(api && token)
+        subscriptionId: sessionSubscriptionId,
+        enabled: sseEnabled && Boolean(sessionEventSubscription)
     })
 
     // Loading auth source

web/src/hooks/useSSE.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, it } from 'vitest'
+import { isGlobalScopedMessageStreamEvent } from './useSSE'
+
+describe('useSSE scope handling', () => {
+    it('treats message stream events as global-scoped skips', () => {
+        expect(isGlobalScopedMessageStreamEvent('global', 'message-received')).toBe(true)
+        expect(isGlobalScopedMessageStreamEvent('global', 'messages-consumed')).toBe(true)
+        expect(isGlobalScopedMessageStreamEvent('global', 'message-cancelled')).toBe(true)
+    })
+
+    it('does not skip session lifecycle events on the global connection', () => {
+        expect(isGlobalScopedMessageStreamEvent('global', 'session-updated')).toBe(false)
+        expect(isGlobalScopedMessageStreamEvent('global', 'session-added')).toBe(false)
+        expect(isGlobalScopedMessageStreamEvent('global', 'session-removed')).toBe(false)
+    })
+
+    it('processes message stream events on full-scoped connections', () => {
+        expect(isGlobalScopedMessageStreamEvent('full', 'message-received')).toBe(false)
+    })
+})

web/src/hooks/useSSE.ts

@@ -21,6 +21,18 @@ type SSESubscription = {
     machineId?: string
 }
 
+export type SSEScope = 'global' | 'full'
+
+const MESSAGE_STREAM_EVENT_TYPES = new Set<SyncEvent['type']>([
+    'message-received',
+    'messages-consumed',
+    'message-cancelled'
+])
+
+export function isGlobalScopedMessageStreamEvent(scope: SSEScope, eventType: SyncEvent['type']): boolean {
+    return scope === 'global' && MESSAGE_STREAM_EVENT_TYPES.has(eventType)
+}
+
 type VisibilityState = 'visible' | 'hidden'
 
 type ToastEvent = Extract<SyncEvent, { type: 'toast' }>
@@ -105,6 +117,7 @@ export function useSSE(options: {
     token: string
     baseUrl: string
     subscription?: SSESubscription
+    scope?: SSEScope
     onEvent: (event: SyncEvent) => void
     onConnect?: () => void
     onDisconnect?: (reason: string) => void
@@ -151,10 +164,11 @@ export function useSSE(options: {
     }, [options.onToast])
 
     const subscription = options.subscription ?? {}
+    const scope = options.scope ?? 'full'
 
     const subscriptionKey = useMemo(() => {
-        return `${subscription.all ? '1' : '0'}|${subscription.sessionId ?? ''}|${subscription.machineId ?? ''}`
-    }, [subscription.all, subscription.sessionId, subscription.machineId])
+        return `${scope}|${subscription.all ? '1' : '0'}|${subscription.sessionId ?? ''}|${subscription.machineId ?? ''}`
+    }, [scope, subscription.all, subscription.sessionId, subscription.machineId])
 
     useEffect(() => {
         if (!options.enabled) {
@@ -425,6 +439,14 @@ export function useSSE(options: {
                 return
             }
 
+            if (scope === 'global' && MESSAGE_STREAM_EVENT_TYPES.has(event.type)) {
+                if (event.type === 'message-received') {
+                    queueSessionListInvalidation()
+                }
+                onEventRef.current(event)
+                return
+            }
+
             if (event.type === 'messages-consumed') {
                 markMessagesConsumed(event.sessionId, event.localIds, event.invokedAt)
             }
@@ -575,7 +597,7 @@ export function useSSE(options: {
             }
             setSubscriptionId(null)
         }
-    }, [options.baseUrl, options.enabled, options.token, subscriptionKey, queryClient, reconnectNonce])
+    }, [options.baseUrl, options.enabled, options.scope, options.token, scope, subscriptionKey, queryClient, reconnectNonce])
 
     return { subscriptionId }
 }

web/src/lib/appSseSubscriptions.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest'
+import { getAppGlobalSseSubscription, getAppSessionSseSubscription } from './appSseSubscriptions'
+
+describe('app SSE subscriptions', () => {
+    it('always uses a global all:true subscription for the session list', () => {
+        expect(getAppGlobalSseSubscription()).toEqual({ all: true })
+    })
+
+    it('uses a session-scoped subscription only when a session is selected', () => {
+        expect(getAppSessionSseSubscription(null)).toBeNull()
+        expect(getAppSessionSseSubscription(undefined)).toBeNull()
+        expect(getAppSessionSseSubscription('')).toBeNull()
+        expect(getAppSessionSseSubscription('session-a')).toEqual({ sessionId: 'session-a' })
+    })
+})

web/src/lib/appSseSubscriptions.ts

@@ -0,0 +1,20 @@
+export type AppGlobalSseSubscription = {
+    all: true
+}
+
+export type AppSessionSseSubscription = {
+    sessionId: string
+}
+
+export function getAppGlobalSseSubscription(): AppGlobalSseSubscription {
+    return { all: true }
+}
+
+export function getAppSessionSseSubscription(
+    selectedSessionId: string | null | undefined
+): AppSessionSseSubscription | null {
+    if (!selectedSessionId) {
+        return null
+    }
+    return { sessionId: selectedSessionId }
+}