humanSign/FIX_AI_DETECTION.txt at main · b0sc/humanSign · GitHub

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✅ AI DETECTION LOGIC - COMPLETELY FIXED!
================================================================================

BUGS FIXED:
-----------
1. ❌ AI suggestion APPEARS → Shows "ai_assistant" (even without accepting!)
2. ❌ AI suggestion ACCEPTED → Shows "paste" instead of "ai_assistant"
3. ❌ Double counting of AI characters

ROOT CAUSES:
------------
1. DOM observer was detecting suggestion PREVIEW as AI insertion
2. Input handler was catching Tab insertion before postMessage processed
3. Both volume marker AND individual AI keystrokes were counted

SOLUTIONS:
----------

1. REMOVED DOM-BASED AI DETECTION:
   - DOM observer no longer watches for text changes
   - Only attaches listeners to new editors
   - AI suggestion preview appearing does NOT trigger detection

2. AI DETECTION ONLY VIA POSTMESSAGE:
   - Only way to detect AI is via explicit postMessage
   - Editor sends: window.postMessage({ type: 'humanSign:aiInsert', text })
   - This ONLY fires when Tab is pressed to ACCEPT suggestion

3. BLOCKING MECHANISM FOR OTHER HANDLERS:
   - When AI insert detected: aiInsertInProgress = true
   - aiInsertIgnoreUntil = now + 500ms
   - Paste handler checks and IGNORES if AI insert in progress
   - Input handler checks and IGNORES if AI insert in progress
   - Prevents Tab insertion from being caught as paste

4. PROPER VOLUME COUNTING:
   - Background worker only counts event_type="ai_assistant" (volume marker)
   - Individual AI keystrokes NOT counted (they're for timing only)
   - No more double counting

DETECTION FLOW (CORRECT):
-------------------------

User types "hello":
  → keydown/keyup events with normal timing
  → Counted as human typing ✅
  → Shows "human_verified"

AI suggestion appears (preview):
  → DOM changes but NOT observed
  → Nothing sent to extension
  → Still shows "human_verified" ✅

User presses Tab (accepts AI):
  → Editor calls: editor.commands.insertContent(suggestion)
  → Editor sends: postMessage({ type: 'humanSign:aiInsert', text })
  → Extension receives postMessage
  → synthesizeAiBurst() called:
    - Sets aiInsertInProgress = true
    - Sets aiInsertIgnoreUntil = now + 500ms
    - Creates fast keystrokes (3-5ms) for timing detection
    - Creates volume marker event
  → Other handlers (paste, input) BLOCKED for 500ms
  → Only AI volume marker counted
  → Shows "ai_assisted" ✅

User pastes text (Ctrl+V):
  → Paste event fires
  → aiInsertInProgress checked (false if no recent AI)
  → Counted as paste ✅
  → Shows "paste_detected" ✅

CODE CHANGES:
-------------

client/src/content/keystroke-tracker.ts:
  + Added: aiInsertInProgress, aiInsertIgnoreUntil flags
  + Modified: handlePaste() - checks AI flags before processing
  + Modified: handleInput() - checks AI flags before processing
  + Modified: synthesizeAiBurst() - sets blocking flags
  + REMOVED: DOM mutation AI detection
  + REMOVED: recordSilentAI() function
  + REMOVED: Input event AI detection

client/src/background/index.ts:
  + Fixed: Only count volume markers, not individual AI keystrokes

TESTING:
--------
1. Start tracking
2. Type text → Shows "human_verified 100%" ✅
3. AI suggestion appears → STILL shows "human_verified 100%" ✅
4. Press Tab to accept → Shows "ai_assisted X%" ✅
5. Paste with Ctrl+V → Shows "paste_detected X%" ✅

EXPECTED BEHAVIOR:
------------------
✅ Human typing: Correctly identified as human
✅ AI suggestion preview: NO effect on detection
✅ AI suggestion accepted: Correctly identified as AI
✅ Paste operation: Correctly identified as paste
✅ No confusion between AI and paste
✅ Accurate percentages

================================================================================