Thanks!
We're using the Google Picker API - https://developers.google.com/photos/picker/reference/rest
You create a picker "session" which is a link where the user can select images from Google's side. Then you poll the session and once the user is done, you can get access to the media items (imgs and videos) that the user selected.
At first, we wanted to auto-sync galleries and were bummed by the way this API works, but tbh it ended up being more private and secure for the user (no auto-syncing that embarrassing picture that shouldn't be online) and helped us avoid implementing a picker on our end.
The session is active for couple of hours IIRC. Once the user is done with the selection we upload the images to our servers (Supabase storage) and delete the GPhotos session.
At first, we wanted to auto-sync galleries and were bummed by the way this API works, but tbh it ended up being more private and secure for the user (no auto-syncing that embarrassing picture that shouldn't be online) and helped us avoid implementing a picker on our end.