I don't have any book recommendations to make since API design is more art than science. As such I'd recommend that you beta test the API (route names, payloads

I don't have any book recommendations to make since API design is more art than science. As such I'd recommend that you beta test the API (route names, payloads, etc) with a few potential users to gauge durability and the ease with which users can intuit. The last thing you want is to release new version quickly or to require users to always refer to your documentation. Some of these problems can be solved with an SDK (highly recommend, as it can greatly improve developer experience especially in a modern text editor or IDE) or switching to GraphQL (not without its own problems).