@white-balloon-205 I think it is your example on that gist.

If you use the regular Function constructor, you will need to creat a Role and attach policies to that role manually, and the. Pass that role to the Function. CallbackFunction takes care of automating a bit of that boilerplate in the common case, but it’s equivalent to doing it manually.

Right, thank you for clearing that up. But why such a difference in the interface? Seems confusing.

Mostly for historical reasons - and agreed that this is a non-orthogonality in the api design here that can be confusing.