Fair questions
Why an extension and not a website?
Goodreads shut off its public API in 2020, and Amazon has never let
anyone near your cart. A website would need both your passwords. This
needs neither — it works inside the tabs you're already signed in to.
What do you collect?
Nothing. No server, no account, no analytics. Books without an ISBN get
an anonymous title lookup at Open Library. That's the lot.
What if Goodreads changes something?
You get a CSV to drop into their bulk importer instead. Less magic, same
books.
Will it mess with my Amazon cart?
Only if you tick the box, and only for books Goodreads confirmed. Wish
lists are never touched.