pdf_fill_form
Fill form fields in PDF documents with specified values to complete digital forms. This tool populates text fields, checkboxes, and other form elements in PDF files.
Instructions
Fill form fields in a PDF with values.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| pdf_path | Yes | ||
| field_values | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Implementation Reference
- Primary handler implementation for the 'pdf_fill_form' tool. Uses PyMuPDF to iterate through PDF pages and widgets, filling form fields matching keys in field_values dictionary based on widget type. Includes input validation, error handling, and saves output to timestamped file. The @mcp.tool() decorator handles registration and schema inference from type hints and docstring.
@mcp.tool() async def pdf_fill_form( pdf_path: str, field_values: Dict[str, Any] ) -> str: """Fill form fields in a PDF with values.""" if not os.path.exists(pdf_path): return f"Error: PDF file not found: {pdf_path}" if not validate_pdf_file(pdf_path): return f"Error: Invalid PDF file: {pdf_path}" try: # Open PDF document doc = fitz.open(pdf_path) filled_fields = 0 # Fill form fields for page_num in range(len(doc)): page = doc[page_num] widgets = page.widgets() for widget in widgets: field_name = widget.field_name if field_name in field_values: value = field_values[field_name] # Set field value based on widget type if widget.field_type == fitz.PDF_WIDGET_TYPE_TEXT: widget.field_value = str(value) elif widget.field_type == fitz.PDF_WIDGET_TYPE_CHECKBOX: widget.field_value = bool(value) elif widget.field_type == fitz.PDF_WIDGET_TYPE_RADIOBUTTON: widget.field_value = str(value) elif widget.field_type == fitz.PDF_WIDGET_TYPE_COMBOBOX: widget.field_value = str(value) widget.update() filled_fields += 1 if filled_fields == 0: doc.close() return "No matching form fields found to fill." # Generate output filename output_path = generate_output_filename(pdf_path) # Save the modified PDF doc.save(output_path) doc.close() return f"Successfully filled {filled_fields} form fields. Output saved to: {output_path}" except Exception as e: return f"Error filling form fields: {str(e)}" - Helper function used by pdf_fill_form to validate the input PDF file is valid by attempting to open it with PyMuPDF.
def validate_pdf_file(pdf_path: str) -> bool: """Validate that the file is a valid PDF.""" try: doc = fitz.open(pdf_path) doc.close() return True except Exception: return False - Helper function used by pdf_fill_form to generate a timestamped output filename to prevent overwriting the original PDF.
def generate_output_filename(input_path: str, suffix: str = "modified") -> str: """Generate a new filename with timestamp to avoid overwriting originals.""" path = Path(input_path) timestamp = datetime.now().strftime("%Y%m%d_%H%M%S") return str(path.parent / f"{path.stem}_{suffix}_{timestamp}{path.suffix}") - pdf_manipulation_mcp_server/pdf_server.py:19-19 (registration)Initialization of the FastMCP server instance. All tools decorated with @mcp.tool() are automatically registered here.
mcp = FastMCP("pdf-manipulation")