# Builder Page Error Fixes - Summary

This document summarizes the fixes applied to resolve two critical issues with the builder page reported by the user.

## Issues Fixed

### ✅ Issue 1: Model Selector Unselects After a Few Seconds
**Symptom**: User selects a model from dropdown, but it reverts after 2-3 seconds

**Root Cause**: `refreshCurrentSession()` overwrites user's selection with server state

**Solution**: Added `userJustChangedModel` flag to prevent server from overwriting during refresh

**Files Modified**: `chat/public/builder.js`

### ✅ Issue 2: Message Text Disappears But No Message Sent  
**Symptom**: User types message and clicks send, text disappears but nothing is sent

**Root Cause**: Input cleared before ensuring session exists

**Solution**: Moved input clearing to after session confirmation

**Files Modified**: `chat/public/builder.html`

## Quick Test Guide

### Test Model Selector:
1. Open builder page
2. Select a different model from dropdown
3. Wait 5 seconds
4. **Result**: Model should stay selected ✓

### Test Message Sending:
1. Open builder page (fresh or without session)
2. Type: "Create a contact form plugin"
3. Click send immediately
4. **Result**: Message should be sent, input cleared only after success ✓

## Technical Implementation

### Model Selector Fix (builder.js)
```javascript
let userJustChangedModel = false;  // New flag

// Set flag when user changes model
if (!programmaticModelChange) {
  userJustChangedModel = true;
}
await refreshCurrentSession();
setTimeout(() => { userJustChangedModel = false; }, 500);

// Skip model update during refresh if user just changed it
if (session.model && !userJustChangedModel) {
  el.modelSelect.value = session.model;
}
```

### Message Sending Fix (builder.html)
```javascript
// REMOVED early input clearing
// input.value = '';  ❌

// Input now cleared AFTER session confirmed
await sendPlanMessage(content);

// Inside sendPlanMessage:
await ensureSessionExists();
if (!state.currentSessionId) {
  return;  // Keep input if session failed
}
input.value = '';  // ✅ Clear only after session OK
```

## Impact
- ✅ Model selection now works reliably
- ✅ No message data loss
- ✅ Better user experience
- ✅ No breaking changes to existing functionality

## Testing Status
- [x] Code changes implemented
- [x] Logic flow verified
- [x] Root causes addressed
- [ ] Manual testing in running application (requires Docker setup)

The fixes are minimal, surgical changes that address the specific root causes without affecting other functionality.