Frappe MCP Server

Instructions

    Amend a document in Frappe (create a new amended version of a cancelled document).
    
    This tool handles document amendment by creating a new document with an amended name
    (e.g., DOC-001-1, DOC-001-2) and copying all relevant field values from the original
    cancelled document, establishing proper linkage via the 'amended_from' field.
    
    Args:
        doctype: DocType name
        name: Document name (case-sensitive) - must be a cancelled document
        
    Returns:
        Success message with new amended document name if successful, or detailed 
        error information if amendment fails due to validation errors or constraints.
    

Implementation Reference

• src/tools/documents.py:762-919 (handler)

  The main handler function for the 'amend_document' tool. It checks if the document is cancelled (docstatus=2), generates a new amended document name (e.g., DOC-001-1), copies fields from the original excluding system fields, sets 'amended_from', clears child names, and creates the new draft document via Frappe API.

  @mcp.tool()
  async def amend_document(
      doctype: str,
      name: str
  ) -> str:
      """
      Amend a document in Frappe (create a new amended version of a cancelled document).
      
      This tool handles document amendment by creating a new document with an amended name
      (e.g., DOC-001-1, DOC-001-2) and copying all relevant field values from the original
      cancelled document, establishing proper linkage via the 'amended_from' field.
      
      Args:
          doctype: DocType name
          name: Document name (case-sensitive) - must be a cancelled document
          
      Returns:
          Success message with new amended document name if successful, or detailed 
          error information if amendment fails due to validation errors or constraints.
      """
      try:
          client = get_client()
          
          # First, get the current document to check its status and get full data
          try:
              doc_response = await client.get(f"api/resource/{doctype}/{name}")
              doc_data = doc_response.get("data", {})
              current_docstatus = doc_data.get("docstatus", None)
              
              if current_docstatus is None:
                  return f"Error: Could not retrieve document {doctype} '{name}'. Document may not exist."
                  
              if current_docstatus == 0:
                  return f"Document {doctype} '{name}' is in Draft status. Only cancelled documents (docstatus=2) can be amended."
                  
              if current_docstatus == 1:
                  return f"Document {doctype} '{name}' is submitted. You must cancel it first before amending."
                  
              if current_docstatus != 2:
                  return f"Document {doctype} '{name}' has unexpected status (docstatus={current_docstatus}). Only cancelled documents (docstatus=2) can be amended."
                  
          except Exception as get_error:
              return f"Error retrieving document for amendment: {get_error}"
          
          # Generate amended document name
          base_name = name
          amended_counter = 1
          
          # Check if this document is already an amendment (contains dash and number)
          if '-' in name:
              parts = name.rsplit('-', 1)
              if len(parts) == 2 and parts[1].isdigit():
                  base_name = parts[0]
                  amended_counter = int(parts[1]) + 1
          
          # Find the next available amended name
          amended_name = f"{base_name}-{amended_counter}"
          while True:
              try:
                  # Check if amended name already exists
                  check_response = await client.get(f"api/resource/{doctype}/{amended_name}")
                  if "data" in check_response:
                      # Name exists, try next number
                      amended_counter += 1
                      amended_name = f"{base_name}-{amended_counter}"
                  else:
                      # Name doesn't exist, we can use it
                      break
              except FrappeApiError as e:
                  # If we get 404, the name doesn't exist and we can use it
                  if e.status_code == 404:
                      break
                  else:
                      # Some other error, we should handle it
                      raise e
          
          # Prepare amended document data
          amended_doc = doc_data.copy()
          
          # Clear system fields that should not be copied
          system_fields = [
              'name', 'creation', 'modified', 'modified_by', 'owner', 
              'docstatus', 'idx', '_user_tags', '_comments', '_assign', '_liked_by'
          ]
          for field in system_fields:
              amended_doc.pop(field, None)
          
          # Set amendment fields
          amended_doc['name'] = amended_name
          amended_doc['amended_from'] = name
          amended_doc['docstatus'] = 0  # New document starts as draft
          
          # Clear any child table names to let Frappe generate new ones
          for key, value in amended_doc.items():
              if isinstance(value, list):
                  for item in value:
                      if isinstance(item, dict):
                          item.pop('name', None)  # Clear child table row names
                          item['parent'] = amended_name  # Update parent reference
          
          # Create the amended document
          response = await client.post(
              f"api/resource/{doctype}",
              json_data=amended_doc
          )
          
          if "data" in response:
              created_doc = response["data"]
              created_name = created_doc.get('name', amended_name)
              return f"✅ Document successfully amended: {doctype} '{created_name}' created from cancelled document '{name}'. The amended document is in Draft status and ready for editing."
          else:
              return f"⚠️ Amendment may have succeeded but response format unexpected: {json.dumps(response, indent=2)}"
              
      except FrappeApiError as api_error:
          # Handle specific Frappe API errors with detailed information
          if api_error.response_data:
              error_data = api_error.response_data
              
              # Check for validation errors in the response
              if "exception" in error_data:
                  exception_msg = error_data["exception"]
                  
                  # Extract user-friendly error messages
                  if "ValidationError" in str(exception_msg):
                      # Common amendment validation errors
                      if "amended_from" in str(exception_msg).lower():
                          return (
                              f"❌ Amendment failed: {doctype} does not have an 'amended_from' field configured. "
                              f"This DocType may not support amendments. Contact your system administrator to enable amendment functionality."
                          )
                      elif "DuplicateEntryError" in str(exception_msg) or "duplicate" in str(exception_msg).lower():
                          return f"❌ Amendment failed: Document name conflict. The amended name may already exist. Please try again."
                      else:
                          # Generic validation error
                          return f"❌ Validation error: {exception_msg}. Please fix the validation issues before amending."
                  
                  elif "PermissionError" in str(exception_msg):
                      return f"❌ Permission denied: You don't have sufficient permissions to amend {doctype} documents."
                  
                  else:
                      # Other exceptions
                      return f"❌ Amendment failed: {exception_msg}"
              
              # Check for server messages with more details
              if "_server_messages" in error_data:
                  try:
                      messages = json.loads(error_data["_server_messages"])
                      if messages:
                          msg_data = json.loads(messages[0])
                          user_message = msg_data.get("message", "Unknown error")
                          return f"❌ Amendment failed: {user_message}"
                  except (json.JSONDecodeError, KeyError, IndexError):
                      pass
          
          return f"❌ Amendment failed: {api_error}"
          
      except Exception as error:
          return _format_error_response(error, "amend_document")

• src/server.py:40-40 (registration)

  Invocation of documents.register_tools(mcp), which registers the amend_document tool (and other document tools) with the MCP server instance.

  documents.register_tools(mcp)