C is the way to code here. That JSON library, JSMN, is pretty slick, very low level, I used it before, but I use C++ now and ‘JSON for modern C++’ . Still working on my CMake port , will post here when done 
GitHub
initial json decoding · damus-io/nostrdb@32b0e57
The unfairly fast embedded nostr database backed by lmdb - initial json decoding · damus-io/nostrdb@32b0e57