Yes. Activate the chronological order then use .AskChildrenOrder to get a list of components in order; the first in the list will be the first that was added to the assembly.
Thanks, I will try it. Is it necessarily to explicitly activate the order, or can I just refer to it?
According to the API docs:
Given a parent NXOpen.Assemblies.Component this method returns immediate child NXOpen.Assemblies.Component s
in the same order in which they are ordered in this NXOpen.Assemblies.ComponentOrder
Since it only takes the parent component as input and not a specified order, it would seem that you need to activate the desired order first.