freecad mcp

Instructions

Args:
    doc_name: The name of the document to edit the object in.
    obj_name: The name of the object to edit.
    obj_properties: The properties of the object to edit.

Returns:
    A message indicating the success or failure of the object editing and a screenshot of the object.

Implementation Reference

• src/freecad_mcp/server.py:336-370 (handler)

  Primary MCP tool handler for 'edit_object'. Proxies the call to FreeCADConnection.edit_object, handles errors, formats response with success message and optional screenshot.

  @mcp.tool()
  def edit_object(
      ctx: Context, doc_name: str, obj_name: str, obj_properties: dict[str, Any]
  ) -> list[TextContent | ImageContent]:
      """Edit an object in FreeCAD.
      This tool is used when the `create_object` tool cannot handle the object creation.
  
      Args:
          doc_name: The name of the document to edit the object in.
          obj_name: The name of the object to edit.
          obj_properties: The properties of the object to edit.
  
      Returns:
          A message indicating the success or failure of the object editing and a screenshot of the object.
      """
      freecad = get_freecad_connection()
      try:
          res = freecad.edit_object(doc_name, obj_name, {"Properties": obj_properties})
          screenshot = freecad.get_active_screenshot()
  
          if res["success"]:
              response = [
                  TextContent(type="text", text=f"Object '{res['object_name']}' edited successfully"),
              ]
              return add_screenshot_if_available(response, screenshot)
          else:
              response = [
                  TextContent(type="text", text=f"Failed to edit object: {res['error']}"),
              ]
              return add_screenshot_if_available(response, screenshot)
      except Exception as e:
          logger.error(f"Failed to edit object: {str(e)}")
          return [
              TextContent(type="text", text=f"Failed to edit object: {str(e)}")
          ]

• src/freecad_mcp/server.py:33-34 (helper)

  Proxy method in FreeCADConnection class that forwards the edit_object RPC call to the FreeCAD XMLRPC server.

  def edit_object(self, doc_name: str, obj_name: str, obj_data: dict[str, Any]) -> dict[str, Any]:
      return self.server.edit_object(doc_name, obj_name, obj_data)

• addon/FreeCADMCP/rpc_server/rpc_server.py:152-162 (helper)

  XMLRPC server method for edit_object that queues the GUI-safe editing task and returns success/error response.

  def edit_object(self, doc_name: str, obj_name: str, properties: dict[str, Any]) -> dict[str, Any]:
      obj = Object(
          name=obj_name,
          properties=properties.get("Properties", {}),
      )
      rpc_request_queue.put(lambda: self._edit_object_gui(doc_name, obj))
      res = rpc_response_queue.get()
      if res is True:
          return {"success": True, "object_name": obj.name}
      else:
          return {"success": False, "error": res}

• addon/FreeCADMCP/rpc_server/rpc_server.py:342-375 (helper)

  GUI-thread safe implementation that performs the actual property setting on FreeCAD objects, handling special cases like References and Placement.

  def _edit_object_gui(self, doc_name: str, obj: Object):
      doc = FreeCAD.getDocument(doc_name)
      if not doc:
          FreeCAD.Console.PrintError(f"Document '{doc_name}' not found.\n")
          return f"Document '{doc_name}' not found.\n"
  
      obj_ins = doc.getObject(obj.name)
      if not obj_ins:
          FreeCAD.Console.PrintError(f"Object '{obj.name}' not found in document '{doc_name}'.\n")
          return f"Object '{obj.name}' not found in document '{doc_name}'.\n"
  
      try:
          # For Fem::ConstraintFixed
          if hasattr(obj_ins, "References") and "References" in obj.properties:
              refs = []
              for ref_name, face in obj.properties["References"]:
                  ref_obj = doc.getObject(ref_name)
                  if ref_obj:
                      refs.append((ref_obj, face))
                  else:
                      raise ValueError(f"Referenced object '{ref_name}' not found.")
              obj_ins.References = refs
              FreeCAD.Console.PrintMessage(
                  f"References updated for '{obj.name}' in '{doc_name}'.\n"
              )
              # delete References from properties
              del obj.properties["References"]
          set_object_property(doc, obj_ins, obj.properties)
          doc.recompute()
          FreeCAD.Console.PrintMessage(f"Object '{obj.name}' updated via RPC.\n")
          return True
      except Exception as e:
          return str(e)