MCP Web Browser Server

Instructions

Navigate to a specific URL and return the page's HTML content.

Args:
    url: The full URL to navigate to
    context: Optional context object for logging (ignored)

Returns:
    The full HTML content of the page

Implementation Reference

• src/mcp_web_browser/server.py:84-132 (handler)

  The core handler function for the 'browse_to' tool. Uses Playwright to launch a browser (if needed), create a new page, navigate to the given URL with networkidle wait and 30s timeout, ignoring HTTPS errors, and returns the full HTML content of the page.

  @mcp.tool()
  async def browse_to(url: str, context: Optional[Any] = None) -> str:
      """
      Navigate to a specific URL and return the page's HTML content.
      
      Args:
          url: The full URL to navigate to
          context: Optional context object for logging (ignored)
      
      Returns:
          The full HTML content of the page
      """
      global _current_page, _browser, _browser_context
      
      # Ensure browser is launched with SSL validation disabled
      _, browser_context = await _ensure_browser()
      
      # Close any existing page
      await _close_current_page()
      
      # Optional logging, but do nothing with context
      print(f"Navigating to {url}", file=sys.stderr)
      
      try:
          # Create a new page and navigate
          _current_page = await browser_context.new_page()
          
          # Additional options to handle various SSL/security issues
          await _current_page.goto(url, 
              wait_until='networkidle',
              timeout=30000,  # 30 seconds timeout
          )
          
          # Get full page content including dynamically loaded JavaScript
          page_content = await _current_page.content()
          
          # Optional: extract additional metadata
          try:
              title = await _current_page.title()
              print(f"Page title: {title}", file=sys.stderr)
          except Exception:
              pass
          
          return page_content
      
      except Exception as e:
          print(f"Error navigating to {url}: {e}", file=sys.stderr)
          raise

• src/mcp_web_browser/server.py:84-84 (registration)

  The @mcp.tool() decorator registers the browse_to function as an MCP tool.

  @mcp.tool()

• src/mcp_web_browser/server.py:21-35 (helper)

  Helper function to ensure the Playwright Chromium browser and context are initialized, with HTTPS errors ignored.

  async def _ensure_browser():
      """Ensure a browser instance is available with SSL validation disabled"""
      global _browser, _browser_context, _playwright_instance
      
      if _browser is None:
          playwright_module = _import_playwright()
          _playwright_instance = await playwright_module().start()
          _browser = await _playwright_instance.chromium.launch()
          
          # Create a browser context that ignores HTTPS errors
          _browser_context = await _browser.new_context(
              ignore_https_errors=True,  # Ignore SSL certificate errors
          )
      return _browser, _browser_context

• src/mcp_web_browser/server.py:36-45 (helper)

  Helper to close the current browser page before navigating to a new URL.

  async def _close_current_page():
      """Close the current page if it exists"""
      global _current_page
      if _current_page:
          try:
              await _current_page.close()
          except Exception:
              pass
          _current_page = None