# Style Detection 404 Error Analysis
**Date:** October 1, 2025  
**Issue:** `GET /api/style-detection/session-analyses` returning 404 Not Found  
**Impact:** Low - Feature degrades gracefully, no user-facing errors

---

## 🔍 Root Cause Analysis

### **The Problem:**

**Frontend calls:**
```typescript
// Line 252 in websiteUtils.ts
const res = await fetch('/api/style-detection/session-analyses');
```

**Backend registered at:**
```python
# Line 43 in component_logic.py
router = APIRouter(prefix="/api/onboarding", tags=["component_logic"])

# Line 645 in component_logic.py
@router.get("/style-detection/session-analyses")
```

**Actual endpoint:**
```
/api/onboarding/style-detection/session-analyses
     ^^^^^^^^^^^^ Missing prefix!
```

**Frontend calling:**
```
/api/style-detection/session-analyses
     ❌ No /onboarding prefix
```

**Result:** 404 Not Found ❌

---

## 📋 What Is This Endpoint?

### **Purpose:**
Pre-fill the website URL input field with the last analyzed website from the user's session.

### **User Experience:**
```
User Journey:
1. User analyzes website: example.com (Step 2)
2. User completes onboarding
3. User starts new session / refreshes page
4. Returns to Step 2 (Website Analysis)
5. ✅ Website field auto-filled with: example.com
6. User doesn't have to type URL again
```

**UX Benefit:** Convenience feature - saves user from re-typing

---

## 🎯 Why It's Being Called

### **Location:** `WebsiteStep.tsx` (Lines 192-206)

```typescript
useEffect(() => {
  // Prefill from last session analysis on mount
  const loadLastAnalysis = async () => {
    const result = await fetchLastAnalysis();  // ← Calls the 404 endpoint
    if (result.success) {
      if (result.website) {
        setWebsite(result.website);  // Auto-fill URL
      }
      if (result.analysis) {
        setAnalysis(result.analysis);  // Load previous analysis
      }
    }
  };
  loadLastAnalysis();
}, []);
```

**Trigger:** Component mounts (every time user visits Step 2)

---

## 📊 Current Impact

### **User Experience:**
- ✅ **No visible errors** - Error caught and handled gracefully
- ✅ **Feature fails silently** - Just doesn't pre-fill
- ✅ **User can still proceed** - Manual URL entry works fine
- ⚠️ **Slightly inconvenient** - User must re-type URL

### **System Impact:**
- ⚠️ **Backend logs pollution** - 404 errors on every Step 2 visit
- ⚠️ **Network noise** - Unnecessary failed requests
- ✅ **No crashes** - Error handled properly

**Severity:** 🟡 Low (convenience feature, not critical)

---

## 🔧 Solutions

### **Option 1: Fix Frontend URL (Quick Fix - 30 seconds)**

```typescript
// frontend/src/components/OnboardingWizard/WebsiteStep/utils/websiteUtils.ts
// Line 252

// Before:
const res = await fetch('/api/style-detection/session-analyses');

// After:
const res = await fetch('/api/onboarding/style-detection/session-analyses');
//                        ^^^^^^^^^^^^ Add missing prefix
```

**Pros:**
- ✅ Quick fix (1 line change)
- ✅ Restores functionality
- ✅ No breaking changes

**Cons:**
- None

**Recommendation:** ✅ **Do this**

---

### **Option 2: Update Backend Route
