Office Word MCP Server

Instructions

Implementation Reference

• word_document_server/tools/protection_tools.py:26-81 (handler)

  Core handler function implementing password protection logic using msoffcrypto to encrypt the Word document.

  async def protect_document(filename: str, password: str) -> str:
      """Add password protection to a Word document.
  
      Args:
          filename: Path to the Word document
          password: Password to protect the document with
      """
      filename = ensure_docx_extension(filename)
  
      if not os.path.exists(filename):
          return f"Document {filename} does not exist"
  
      # Check if file is writeable
      is_writeable, error_message = check_file_writeable(filename)
      if not is_writeable:
          return f"Cannot protect document: {error_message}"
  
      try:
          # Read the original file content
          with open(filename, "rb") as infile:
              original_data = infile.read()
  
          # Create an msoffcrypto file object from the original data
          file = msoffcrypto.OfficeFile(io.BytesIO(original_data))
          file.load_key(password=password) # Set the password for encryption
  
          # Encrypt the data into an in-memory buffer
          encrypted_data_io = io.BytesIO()
          
          file.encrypt(password=password, outfile=encrypted_data_io) 
  
          # Overwrite the original file with the encrypted data
          with open(filename, "wb") as outfile:
              outfile.write(encrypted_data_io.getvalue())
  
          
          base_path, _ = os.path.splitext(filename)
          metadata_path = f"{base_path}.protection"
          if os.path.exists(metadata_path):
              os.remove(metadata_path)
  
          return f"Document {filename} encrypted successfully with password."
  
      except Exception as e:
          # Attempt to restore original file content on failure
          try:
              if 'original_data' in locals():
                  with open(filename, "wb") as outfile:
                      outfile.write(original_data)
                  return f"Failed to encrypt document {filename}: {str(e)}. Original file restored."
              else:
                   return f"Failed to encrypt document {filename}: {str(e)}. Could not restore original file."
          except Exception as restore_e:
               return f"Failed to encrypt document {filename}: {str(e)}. Also failed to restore original file: {str(restore_e)}"

• word_document_server/main.py:286-290 (registration)

  MCP tool registration using FastMCP @mcp.tool() decorator. Thin wrapper delegating to protection_tools.protect_document.

  @mcp.tool()
  def protect_document(filename: str, password: str):
      """Add password protection to a Word document."""
      return protection_tools.protect_document(filename, password)

• word_document_server/tools/__init__.py:28-31 (helper)

  Export of protect_document function from protection_tools module for use in main.py.

  from word_document_server.tools.protection_tools import (
      protect_document, add_restricted_editing,
      add_digital_signature, verify_document
  )