It's just embedded as a /cashu subdirectory & iframe in the user interface. I'd like to make it more seamlessly integrated, so you could quick zap, show the balance and automatically redeem incoming zaps from npub.cash without the wallet page being open.
Discussion
As an iframe you could point it to https://nuts.cash/home
This will claim all zaps automatically and show you your balance from incoming cashu in DM and from nutszap (nip-61)
This will not let you nutszap others with ecash
I’m planning on opening the code soon, the cashu integration does not take more than 500ish lines of code