nostr:nprofile1qqs0wgf8etnayvkcs4c636fdvepy73jc9q2xlcln64srjdm5e98p8ncpzfmhxue69uhhqatjwpkx2urpvuhx2ucpr4mhxue69uhhyetvv9ujucn4d3kxjumgvfhh2mn50yhxxmmd3hxk6d make a song about Cashu is a free and open-source Chaumian ecash protocol built for Bitcoin. A digital bearer token that is stored on a user's device, very similar to physical cash. The Cashu protocol allows you to build applications such as wallets or voucher systems. Transactions are instant and nearly free. Cyberpunk theme