freecad mcp

Instructions

Args:
    relative_path: The relative path of the part to insert.

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

Implementation Reference

• src/freecad_mcp/server.py:467-497 (handler)

  MCP handler for 'insert_part_from_library' tool. Proxies to FreeCADConnection RPC and adds response with optional screenshot.

  @mcp.tool()
  def insert_part_from_library(ctx: Context, relative_path: str) -> list[TextContent | ImageContent]:
      """Insert a part from the parts library addon.
  
      Args:
          relative_path: The relative path of the part to insert.
  
      Returns:
          A message indicating the success or failure of the part insertion and a screenshot of the object.
      """
      freecad = get_freecad_connection()
      try:
          res = freecad.insert_part_from_library(relative_path)
          screenshot = freecad.get_active_screenshot()
          
          if res["success"]:
              response = [
                  TextContent(type="text", text=f"Part inserted from library: {res['message']}"),
              ]
              return add_screenshot_if_available(response, screenshot)
          else:
              response = [
                  TextContent(type="text", text=f"Failed to insert part from library: {res['error']}"),
              ]
              return add_screenshot_if_available(response, screenshot)
      except Exception as e:
          logger.error(f"Failed to insert part from library: {str(e)}")
          return [
              TextContent(type="text", text=f"Failed to insert part from library: {str(e)}")
          ]

• addon/FreeCADMCP/rpc_server/parts_library.py:8-17 (helper)

  Core implementation: merges the specified FCStd part file from the user's parts library into the active FreeCAD document.

  def insert_part_from_library(relative_path):
      parts_lib_path = os.path.join(FreeCAD.getUserAppDataDir(), "Mod", "parts_library")
      part_path = os.path.join(parts_lib_path, relative_path)
  
      if not os.path.exists(part_path):
          raise FileNotFoundError(f"Not found: {part_path}")
  
      FreeCADGui.ActiveDocument.mergeProject(part_path)

• src/freecad_mcp/server.py:39-40 (helper)

  Proxy method in FreeCADConnection class that forwards the call to the XML-RPC server.

  def insert_part_from_library(self, relative_path: str) -> dict[str, Any]:
      return self.server.insert_part_from_library(relative_path)

• addon/FreeCADMCP/rpc_server/rpc_server.py:437-441 (registration)

  RPC server registration of FreeCADRPC instance, which exposes the insert_part_from_library method.

  rpc_server_instance = SimpleXMLRPCServer(
      (host, port), allow_none=True, logRequests=False
  )
  rpc_server_instance.register_instance(FreeCADRPC())

• addon/FreeCADMCP/rpc_server/rpc_server.py:210-216 (helper)

  RPC method dispatcher: queues the insertion task for GUI thread safety and returns success/error response.

  def insert_part_from_library(self, relative_path):
      rpc_request_queue.put(lambda: self._insert_part_from_library(relative_path))
      res = rpc_response_queue.get()
      if res is True:
          return {"success": True, "message": "Part inserted from library."}
      else:
          return {"success": False, "error": res}