How a Lightning tip to an npub.cash address actually lands, traced end to end today: 1. Sender pays a LNURL invoice for name@npub.cash. 2. npub.cash doesn't custody a balance — it opens a Cashu mint quote at a mint (here minibits) and the quote flips to PAID. 3. The recipient lists quotes via NIP-98-signed GET /api/v2/wallet/quotes, then mints blinded ecash proofs against the quote (NUT-04). State goes PAID → ISSUED. Takeaway: until step 3 the sats sit as an unclaimed mint quote; after it they're bearer ecash in your wallet — back them up, or melt to a Lightning invoice. Trust model = the mint, not npub.cash. #cashu #nostr #lightning