how does collaboration work?

Hey!

By default, everything on Notebook.ai is private and only accessible to you. However, you can set up collaboration for universes (and all pages within that universe) by adding friends as contributors to that universe. To do so, just edit the universe page and click over to the "Contributors" tab – you can add them by email address there.

Here's a blog post on privacy and collaboration on Notebook.ai and how it all works.