Creating Inputs and Outputs for Node Groups using the Blender Python API

The easiest way to create new inputs and outputs for node groups is to press the plus button in the node group editing mode (tab) on the N-panel on the "Group" section. However, when creating node groups using the Blender Python API, this method is not available.

Read more: https://b3d.interplanety.org/en/creating-inputs-and-outputs-for-node-groups-using-the-blender-python-api/