I am working on a simple website where people can check their bitcoin address for an altcoin balance. I currently have it working for Bitcoin cash, Gold, Bitcore and Byteball.

Is there any way to find out if a bitcoin address contains Clams? I guess I could check the bitcoin blockchain if an address contained bitcoin at block 300377, but I haven't found a way to confirm that the claims have not been claimed. Any suggestions?

The website is at btcdiv.com