Yes, that’s what I was telling you yesterday;
Found it: https://github.com/cashubtc/nuts/blob/main/05.md
You can "melt" a token to pay an LN invoice. To convert to Bitcoin you can plug in an LN invoice from boltz.exchange
This also makes it possible for "nutzap" wallets to do "regular zaps", by getting the invoice and then "melting" to it.
I think it's actually even possible to receive NIP-57 zaps, with a small glue layer between LNURL and the Cashu mint. The server needs to associate their Cashu mint somehow, then it give them a Lightning address. The LNURL call will make a proxy request to the "mint" endpoint internally to generate LN invoices.
Discussion
Fuck, accidental post. I was saying you can have a NIP-60 wallet that pays NIP-57 zaps
Which is why NIP-60 and NIP-61 are independent nips, they are great together, but are independent of each other. You could receive NIP-61 nutzaps and immediately melt them into your self-custodial wallet.
Self-custodial LN on mobile sucks. But NIP-61 could make it possible; essentially instead of creating a hodl invoice in the route, which is problematic from a liquidity and also causes issues when both sender and receiver are on mobile (as was illustrated when the mutiny and Zeus folks were at war), paying via a NIP-61 nutzap is like “parking” the sats on a mint until the receiver comes online and redeems all the cashu into their wallet.