Is there a way to trigger some code whenever a node is pasted or duplicated in a scene? I thought that maybe the OnCreated global event listed here [www.sidefx.com] would have done it, but that doesn't seem to be the case. I am trying to build a method of assigning a persistent unique ID to nodes, and currently this is the only part of the puzzle I seem to be missing. Any ideas?

Hello,
OnLoaded will do what you want.
To avoid calling it when Houdini is loading the scene you can use hou.hipFile.isLoadingHipFile()
Example in OnLoaded:

Thanks FDX. That's exactly what I was looking for.

That doesn't seem to be working anymore ?