Frida Game Hacking MCP

Instructions

Take a screenshot of a specific window.

Args:
    target: Window title (string) or HWND handle (integer)
    save_path: Optional path to save the screenshot (PNG). If empty, returns base64.

Returns:
    Screenshot info with base64 data or saved file path.

Implementation Reference

• src/frida_game_hacking_mcp/server.py:1949-2049 (handler)

  The handler function for the 'screenshot_window' tool. It captures a screenshot of a specified window using Windows API (win32gui, win32ui) and PIL for image processing, supporting both base64 output and file saving.

  @mcp.tool()
  def screenshot_window(target: Union[str, int], save_path: str = "") -> Dict[str, Any]:
      """
      Take a screenshot of a specific window.
      
      Args:
          target: Window title (string) or HWND handle (integer)
          save_path: Optional path to save the screenshot (PNG). If empty, returns base64.
      
      Returns:
          Screenshot info with base64 data or saved file path.
      """
      if not SCREENSHOT_AVAILABLE:
          return {"error": "Screenshot support not available. Install: pip install pywin32 pillow"}
      
      try:
          # Find the window
          hwnd = None
          if isinstance(target, int):
              hwnd = target
          else:
              def find_window(h, _):
                  nonlocal hwnd
                  if win32gui.IsWindowVisible(h):
                      title = win32gui.GetWindowText(h)
                      if title and target.lower() in title.lower():
                          hwnd = h
                          return False
                  return True
              win32gui.EnumWindows(find_window, None)
          
          if not hwnd:
              return {"error": f"Window not found: {target}"}
          
          # Get window dimensions
          rect = win32gui.GetWindowRect(hwnd)
          width = rect[2] - rect[0]
          height = rect[3] - rect[1]
          
          if width <= 0 or height <= 0:
              return {"error": "Window has invalid dimensions"}
          
          # Capture the window
          hwnd_dc = win32gui.GetWindowDC(hwnd)
          mfc_dc = win32ui.CreateDCFromHandle(hwnd_dc)
          save_dc = mfc_dc.CreateCompatibleDC()
          
          bitmap = win32ui.CreateBitmap()
          bitmap.CreateCompatibleBitmap(mfc_dc, width, height)
          save_dc.SelectObject(bitmap)
          
          # Try PrintWindow first (works for most windows)
          result = ctypes.windll.user32.PrintWindow(hwnd, save_dc.GetSafeHdc(), 2)
          
          if result == 0:
              # Fallback to BitBlt
              save_dc.BitBlt((0, 0), (width, height), mfc_dc, (0, 0), win32con.SRCCOPY)
          
          # Convert to PIL Image
          bmp_info = bitmap.GetInfo()
          bmp_str = bitmap.GetBitmapBits(True)
          
          img = Image.frombuffer(
              'RGB',
              (bmp_info['bmWidth'], bmp_info['bmHeight']),
              bmp_str, 'raw', 'BGRX', 0, 1
          )
          
          # Cleanup
          win32gui.DeleteObject(bitmap.GetHandle())
          save_dc.DeleteDC()
          mfc_dc.DeleteDC()
          win32gui.ReleaseDC(hwnd, hwnd_dc)
          
          # Save or return base64
          if save_path:
              img.save(save_path, 'PNG')
              return {
                  "success": True,
                  "path": save_path,
                  "width": width,
                  "height": height,
                  "window_title": win32gui.GetWindowText(hwnd)
              }
          else:
              buffer = io.BytesIO()
              img.save(buffer, format='PNG')
              img_base64 = base64.b64encode(buffer.getvalue()).decode('utf-8')
              
              return {
                  "success": True,
                  "width": width,
                  "height": height,
                  "window_title": win32gui.GetWindowText(hwnd),
                  "image_base64": img_base64,
                  "format": "png"
              }
      
      except Exception as e:
          return {"error": f"Screenshot failed: {str(e)}"}