How private is a zap? How private is paying an invoice? Presume to self custodial wallets with own nodes. Can the recipient of a payment see the full wallet balance of the sender? For bitcoin this is clear. But how is it for lightning? Would that be different? Happy for guidance.
Discussion
Can't see the wallet balance of the sender.
What you can see via nostr depends on the client/wallet used.
More and more are integrating Nostr so that your zaps are tracked through Nostr.
I sent thousands of sats anonymously through Iris/Alby, and then they started tracking it and now my zaps show up on sites like nostr.band.