As of today, Goodreads users can import their shelves onto Bookish via .csv files.
Bookish CEO Ardy Khazaei commented: "This new functionality on the Bookish site is the latest example of our continued commitment to readers. They asked us for a convenient way to import their shelves from Goodreads, and we listened. This new site feature will further enhance book discovery on Bookish, especially as we roll out personalization features later this summer."
Imported ISBNs that are not currently within the Bookish catalogue will not appear on users' shelves immediately, but will be added to "My Shelves" as those titles are brought in to the site catalogue. The ability to export books from Bookish shelves is also in development.