I am writing a blockchain explorer in php to run off my local Bitcoin Core node. I am getting the RPC to work. I will need some calculated data like estimated btc transferred in a block or btc balance for random addresses (not my own wallet). I can write the php to do this but wondering if there is a library somewhere. I searched github and didn't see this kind of function.
You might have already searched there, but
the better place to find something like this is Github. Anyway, if you wan to make an explorer note that you'll also need a database : making RPC calls on-the-fly at user request is just not viable at all.