Excel MCP Server

Instructions

Implementation Reference

• mcp_excel_server/server.py:253-309 (handler)

  The handler function for the 'update_excel' tool. Decorated with @mcp.tool() for automatic registration in FastMCP. Parses input data (CSV/JSON), handles multiple file formats (.xlsx, .csv, etc.), preserves other sheets in Excel files while updating the specified sheet, and returns success/error messages.
  @mcp.tool() def update_excel(file_path: str, data: str, sheet_name: Optional[str] = "Sheet1", format: Optional[str] = "csv") -> str: """ Update an existing Excel file with new data. Args: file_path: Path to the Excel file to update data: New data in CSV or JSON format sheet_name: Name of the sheet to update (for Excel files) format: Format of the input data ('csv' or 'json') Returns: Confirmation message """ try: # Check if file exists if not os.path.exists(file_path): return f"File not found: {file_path}" # Load new data if format.lower() == 'csv': new_df = pd.read_csv(io.StringIO(data)) elif format.lower() == 'json': new_df = pd.read_json(io.StringIO(data)) else: return f"Unsupported data format: {format}" # Get file extension _, ext = os.path.splitext(file_path) ext = ext.lower() # Read existing file if ext in ['.xlsx', '.xls', '.xlsm']: # For Excel files, we need to read all sheets excel_file = pd.ExcelFile(file_path) with pd.ExcelWriter(file_path) as writer: # Copy all existing sheets for sheet in excel_file.sheet_names: if sheet != sheet_name: df = pd.read_excel(excel_file, sheet_name=sheet) df.to_excel(writer, sheet_name=sheet, index=False) # Write new data to specified sheet new_df.to_excel(writer, sheet_name=sheet_name, index=False) elif ext == '.csv': new_df.to_csv(file_path, index=False) elif ext == '.tsv': new_df.to_csv(file_path, sep='\t', index=False) elif ext == '.json': new_df.to_json(file_path, orient='records') else: return f"Unsupported file extension: {ext}" return f"Successfully updated {file_path}" except Exception as e: return f"Error updating file: {str(e)}"