MCP PDF Forms

Instructions

Implementation Reference

• mcp_pdf_forms/server.py:133-202 (handler)

  The main handler function for the 'highlight_form_field' tool. It opens the PDF using PyMuPDF, locates the specified form field on its page, renders the page at 2x zoom, draws a thick red rectangle around the field using PIL, and returns the resulting PNG image via MCP's Image type. The @mcp.tool() decorator registers it as a tool.
  @mcp.tool() def highlight_form_field(pdf_path: str, field_name: str) -> Image: """ Generate an image with the specified form field highlighted with a red box Args: pdf_path: Path to the PDF file field_name: Name of the form field to highlight Returns: Image of the page with the field highlighted """ try: doc = fitz.open(pdf_path) # Find the field and its page field_found = False field_page = None field_rect = None for page_num, page in enumerate(doc): for widget in page.widgets(): if widget.field_name == field_name: field_found = True field_page = page field_rect = widget.rect break if field_found: break if not field_found: raise ValueError(f"Field '{field_name}' not found in the document") # Render the page as an image zoom = 2 # higher zoom for better quality mat = fitz.Matrix(zoom, zoom) pix = field_page.get_pixmap(matrix=mat) # Convert to PIL Image img = PILImage.frombytes("RGB", [pix.width, pix.height], pix.samples) # Draw red rectangle around the form field draw = ImageDraw.Draw(img) # Scale rectangle coordinates according to zoom factor rect = ( field_rect.x0 * zoom, field_rect.y0 * zoom, field_rect.x1 * zoom, field_rect.y1 * zoom, ) # Draw rectangle with 3-pixel width for i in range(3): draw.rectangle( (rect[0] - i, rect[1] - i, rect[2] + i, rect[3] + i), outline="red" ) # Convert to bytes buffer = io.BytesIO() img.save(buffer, format="PNG") img_bytes = buffer.getvalue() doc.close() # Return MCP Image object return Image(data=img_bytes, format="png") except Exception as e: raise Exception(f"Error highlighting form field: {str(e)}")