Thanks to nostr:npub1q3sle0kvfsehgsuexttt3ugjd8xdklxfwwkh559wxckmzddywnws6cd26p codebase. I just recently implement a Generic API Policy for nfrelay.app to handle RplyFamily spam. Although, example of API server has not fully written yet but feel free to take a look 😄

https://github.com/atrifat/strfry-policies/pull/1