ÿþ# LESSONS.md - Application-Wide Fetch Fix
Date: 2025-09-19

## Major Discovery
This wasn't just Time Tracking - the ENTIRE application had broken fetch authentication!

## Impact
- Every authenticated API call would fail
- Users see loading spinners forever
- Console shows 302 redirects to /login
- Affects messages, notifications, scheduling, analytics, etc.

## Prevention Strategy
1. Create a fetch wrapper function:
   \\\javascript
   function authenticatedFetch(url, options = {}) {
       return fetch(url, { 
           credentials: 'same-origin',
           ...options 
       });
   }
   \\\

2. Use this wrapper everywhere instead of raw fetch()

3. Add to code review checklist:
   - Check all fetch calls include credentials
   - Test in incognito window
   - Check network tab for 302s

## Time Wasted
- Probably hours of user frustration
- Multiple "loading forever" complaints
- All from one missing parameter!