All files are stored in an encrypted regional data center of your choosing and are never used to train models. You can export your full library at any time from Settings → Export.

Yes — open any paper from the list, click the edit icon, and update the summary field. Changes are saved instantly and version history is kept for 90 days.

Collections are lightweight groupings of papers — like playlists. A paper can live in many collections at once, and collections can be shared read-only with teammates.