MCP Web Browser Server

Instructions

Capture screenshot of the current page.

Args:
    full_page: Whether to capture the entire page or just the viewport
    selector: Optional CSS selector to screenshot a specific element
    context: Optional context object for logging (ignored)

Returns:
    Base64 encoded screenshot image

Implementation Reference

• src/mcp_web_browser/server.py:204-244 (handler)

  The main handler function for the 'get_page_screenshots' tool. It captures a screenshot of the current page (full page or viewport) or a specific element, encodes it as base64, and returns it. Requires a page to be loaded via 'browse_to' first.

  async def get_page_screenshots(
      full_page: bool = False, 
      selector: Optional[str] = None,
      context: Optional[Any] = None
  ) -> str:
      """
      Capture screenshot of the current page.
      
      Args:
          full_page: Whether to capture the entire page or just the viewport
          selector: Optional CSS selector to screenshot a specific element
          context: Optional context object for logging (ignored)
      
      Returns:
          Base64 encoded screenshot image
      """
      global _current_page
      
      if not _current_page:
          raise ValueError("No page is currently loaded. Use browse_to first.")
      
      try:
          if selector:
              element = await _current_page.query_selector(selector)
              if not element:
                  raise ValueError(f"No element found with selector: {selector}")
              screenshot_bytes = await element.screenshot()
          else:
              screenshot_bytes = await _current_page.screenshot(full_page=full_page)
          
          # Convert to base64 for easy transmission
          screenshot_base64 = base64.b64encode(screenshot_bytes).decode('utf-8')
          
          print(f"Screenshot captured: {'full page' if full_page else 'viewport'}", file=sys.stderr)
          
          return screenshot_base64
      
      except Exception as e:
          print(f"Error capturing screenshot: {e}", file=sys.stderr)
          raise ValueError(f"Error capturing screenshot: {e}")