How does Nostr work?

The name stands for "Notes and Other Stuff Transmitted by Relays". The protocol was first written in 2020 by a Brazilian developer who goes by fiatjaf, and it's defined in a set of short, numbered documents called NIPs (Nostr Implementation Possibilities). NIP-01 is the core; the rest add features that apps may support.

1. Your account is a key pair

There's no sign-up server. An app generates a private key and derives a public key from it (secp256k1, the same curve as Bitcoin). The public key, usually shown as an npub1…, is your identity. The private key (nsec1…) signs everything you post. Lose it and the account is gone; leak it and someone else can post as you. More on keys, with a converter.

2. Everything is a signed event

A note, a like, a profile, a follow list, a long article: each is an event with the same seven fields. The id is a hash of the content, and sig is a Schnorr signature of that id, so anyone can check that the author wrote exactly this.

{
  "id": "<sha256 of the fields below>",
  "pubkey": "<author's public key, hex>",
  "created_at": 1730700000,
  "kind": 1,
  "tags": [["p", "<someone you mention>"]],
  "content": "Hello, Nostr",
  "sig": "<Schnorr signature of the id>"
}

The kind says what it is: 0 is your profile, 1 a short text note, 3 your follow list, 7 a reaction. Some kinds are replaceable (only the newest version counts, like your profile), some are ephemeral (relays don't store them), and kinds 30000 to 39999 are addressable, such as articles you can edit.

3. Relays store and forward

A relay is a server that accepts events over a WebSocket and serves them back to anyone who asks with a filter ("notes from these people since yesterday"). Your app publishes to several relays and reads from several. Relays can refuse, delete or charge, but they can't forge or alter your events, because the signature would fail. What a relay is, in detail.

To find you, other apps need to know where you publish. You announce that in a relay list (kind 10002, NIP-65), and apps fetch your notes from your listed write relays.

4. Apps are interchangeable

Every app (a "client") reads the same events. Sign in to a second app with the same key and your profile, follows and posts are there, because they were never in the first app. Apps differ in design and features: some are for short notes, some for long articles, photos, video or chat. The app list has the main ones.

The extras are NIPs too: NIP-05 names (you@example.com, checked against a file on that domain), zaps (Lightning payments tied to a post, NIP-57), and private messages (NIP-17, encrypted with NIP-44 and "gift-wrapped" so relays can't read them or see who sent them).

Is Nostr safe?

It's as safe as your private key. The protocol itself is sound: signatures make posts impossible to forge. The risks are practical:

• Your key: an app or website that holds your nsec can lose it. Use a signer, so apps ask for signatures instead of holding the key.
• Everything public is public for good. Notes are copied to many relays. Deleting sends a request (NIP-09), and the spec says itself that deletion can't be guaranteed.
• Metadata: relays see your IP address and what you ask for, like any server. Pick relays you trust, or connect through a VPN or Tor.
• Moderation is per app and per relay. There's no central team removing spam or abuse; apps filter with mute lists, webs of trust and paid or private relays.

Is Nostr dead?

No, but it's small. As of our last check, 1,277 public relays answered, out of 1,429 we know. The main relay programs ship releases (see relay software), and the NIPs repository is still active. Interest is flat rather than growing: English Wikipedia's Nostr article gets a median of about 5,600 views a month (73,000 in the year to November 2026), against 511,000 for Bluesky's in the same year. We don't count users, and the user numbers you'll see elsewhere are estimates from crawling public keys, so treat them with care.

Where it came from

fiatjaf published the idea in 2020 as a simpler alternative to federated networks: no servers to trust, only relays that store signed notes. It grew in late 2022, when Jack Dorsey, a co-founder of Twitter, gave about 14 bitcoin (roughly $245,000 at the time) to fund its development, and apps like Damus reached app stores soon after.