FreeCAD MCP

Instructions

Args:
    doc_name: The name of the document to get the object from.
    obj_name: The name of the object to get.

Returns:
    The object and a screenshot of the object.

Implementation Reference

• src/freecad_mcp/server.py:524-548 (handler)

  Primary MCP tool handler for 'get_object'. Retrieves object properties via FreeCADConnection proxy, serializes to JSON, adds screenshot if available, and returns as TextContent.

  @mcp.tool()
  def get_object(ctx: Context, doc_name: str, obj_name: str) -> dict[str, Any]:
      """Get an object from a document.
      You can use this tool to get the properties of an object to see what you can check or edit.
  
      Args:
          doc_name: The name of the document to get the object from.
          obj_name: The name of the object to get.
  
      Returns:
          The object and a screenshot of the object.
      """
      freecad = get_freecad_connection()
      try:
          screenshot = freecad.get_active_screenshot()
          response = [
              TextContent(type="text", text=json.dumps(freecad.get_object(doc_name, obj_name))),
          ]
          return add_screenshot_if_available(response, screenshot)
      except Exception as e:
          logger.error(f"Failed to get object: {str(e)}")
          return [
              TextContent(type="text", text=f"Failed to get object: {str(e)}")
          ]

• src/freecad_mcp/server.py:84-85 (helper)

  Helper method in FreeCADConnection class that proxies the get_object RPC call to the XML-RPC server.

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

• addon/FreeCADMCP/rpc_server/rpc_server.py:203-209 (helper)

  Backend RPC server implementation of get_object. Fetches the FreeCAD DocumentObject by name and serializes it using serialize_object.

  def get_object(self, doc_name, obj_name):
      doc = FreeCAD.getDocument(doc_name)
      if doc:
          return serialize_object(doc.getObject(obj_name))
      else:
          return None

• addon/FreeCADMCP/rpc_server/serialize.py:50-52 (helper)

  Serialization helper function used to convert FreeCAD objects to JSON-serializable dicts. (Full function spans multiple lines including recursive serialization.)

  def serialize_object(obj):
      if isinstance(obj, list):
          return [serialize_object(item) for item in obj]