Zap (Nostr Lightning tip)

Nostr is an open protocol for decentralised social media in which users are identified by public keys and posts are relayed by independent servers. A zap combines that with Lightning: when a user taps the zap button, their client pays the author's Lightning address and the recipient's wallet service publishes a zap receipt event, defined in a protocol standard known as NIP-57, which clients display next to the post.

Zaps turned micropayments into a social gesture, replacing or complementing likes. Amounts are often tiny, from 21 sats upwards, and creators can earn directly from readers without platforms taking a cut or ads. The concept has spread to other apps that use the same word for quick Lightning tips.

Receipts are public and linked to identities, so zapping reveals who paid whom and how much, unless private zaps are used. Many users rely on custodial wallets or third-party services to send and receive zaps, which reintroduces intermediaries. As with any payment, users should be wary of fake receipts and spam bots.