There's nothing specifically about caching in the Books API ToS (compared to, say, the Maps API which has restrictions) so it's likely covered by the general po

There's nothing specifically about caching in the Books API ToS (compared to, say, the Maps API which has restrictions) so it's likely covered by the general policy: https://developers.google.com/terms#e_prohibitions_on_content https://developers.google.com/terms#e_prohibitions_on_conten... Short short version: you can only cache the responses for as long as the headers say you should