Crons

Scheduled task handlers for automated system maintenance.

• Purpose: Safety net for viewing session cleanup when normal session ending fails
• Schedule: Every minute
• Threshold: Sessions older than 60 seconds without heartbeat updates
• Function: Marks stale sessions as not viewing and syncs to Notion

Multi-Layer Session Ending System:

The viewing system uses a three-tier approach to ensure sessions are properly ended:

1. Primary (Immediate): beforeunload event with sendBeacon

   • Triggers when user closes tab, navigates away, or browser crashes
   • Uses navigator.sendBeacon() for maximum reliability during page unload
   • Falls back to synchronous fetch if sendBeacon fails
   • Most reliable for normal user behavior

2. Secondary (Component Cleanup): React useEffect cleanup

   • Triggers when user navigates within the app (SPA navigation)
   • Runs when React component unmounts normally
   • Uses standard fetch with full error handling
   • Reliable for in-app navigation

3. Tertiary (Safety Net): This cron job

   • Catches any sessions missed by the above methods
   • Handles edge cases: network failures, browser force-quit, system crashes
   • Runs every minute to find sessions with no heartbeat for 60+ seconds
   • Guaranteed cleanup for all scenarios

Processing Flow:

1. Lists all viewing blobs with prefix glimpse--viewing--
2. Checks each blob's lastUpdate timestamp
3. Identifies sessions where:
   • sessionStart is not null (actively viewing)
   • lastUpdate is older than 60 seconds (stale)
4. Updates blob: sets sessionStart to null, updates lastUpdate
5. Immediately syncs to Notion: Sets "Session start" property to null
6. Logs cleanup statistics and any errors

Why This Safety Net is Essential:

• Network failures: Primary/secondary methods may fail to reach server
• Browser crashes: No opportunity for graceful cleanup
• System sleep/hibernate: Processes may be suspended mid-request
• Force quit scenarios: No cleanup functions execute
• Mobile browser behavior: Aggressive tab suspension/termination
• Development/debugging: Stopping processes during testing

Notion Integration:

• Maintains data consistency between blob storage and Notion
• Ensures "Session start" property accurately reflects active sessions
• Prevents "ghost" sessions that appear active but aren't
• Provides reliable session duration tracking

• Purpose: Cleans up orphaned agent blobs
• Schedule: Every minute (configurable in Val Town UI)
• Function: Deletes agent blobs where the agent ID doesn't match the demo's "Glimpse agents" relation in Notion
• Read-Only Notion: Only reads Notion data, never modifies it
• Blob Cleanup: Removes mismatched/orphaned blobs to keep storage synchronized with Notion

Cron schedules are managed through the Val Town web interface. Click on each cron file to modify its schedule as needed.