Glossary
Definitions, in the sense this site uses them. Two of these look almost identical and one of them will cost you your identity, so that pair is first.
nsec
Your private key, in bech32. Never share it, never paste it into a website, never send it to anyone for any reason. There is no reset and no recovery: whoever holds it is you.
npub
Your public key, in bech32, derived from the nsec in one direction only. Share it freely — it is how people find and verify you.
npub and nsec differ by three characters and are the same length. That is why the prefixes exist: a person can tell them apart across a room, and software can refuse an nsec where an npub belongs before anything is transmitted.
Event
The only data structure. Seven fields, signed by the key that wrote it. A note, a profile, a follow list, a reaction and a deletion request are all events; what distinguishes them is kind.
Kind
An integer saying how to interpret an event. 0 is a profile, 1 is a note, 3 is a follow list, 7 is a reaction. The ranges carry behaviour: 10000–19999 are replaceable, 20000–29999 are ephemeral, 30000–39999 are addressable.
Tags
An array of arrays carrying every reference to anything outside the event. e points at another event, p at another key, t is a hashtag, d identifies an addressable event. Most threading bugs live here.
Relay
A server that stores events and hands them out. It is not an account provider and holds no identity. Which relays you connect to determines what you see, which is the single most surprising thing about Nostr.
Relay set
The relays a client is connected to. Two people with different sets legitimately see different replies to the same note, and neither client is wrong.
NIP
Nostr Implementation Possibility — the specification documents. See the index, where each one has a number, a status and a plain-language line.
Zap
A Lightning payment with a public receipt published as a Nostr event, so a tip is visible under a post. The receipt is signed by the recipient’s wallet server rather than by the sender, which is a trust assumption worth knowing about.
Signer · bunker
Software holding your private key that signs events on request so an application never sees the key. A browser extension does this locally (NIP-07); a remote signer, often called a bunker, does it from another device (NIP-46).
Using one is the difference between trusting an app with your identity and lending it a signature.