| Communication protocol | |
 A common logo used to represent Nostr | |
| Abbreviation | Nostr |
|---|---|
| Purpose | Decentralized social networking |
| Developer(s) | fiatjaf |
| Introduction | March 2020; 5 years ago (2020-03)[1] |
| Port(s) | 80, 443 |
| Website | github.com/nostr |
Nostr (acronym forNotes and Other Stuff Transmitted by Relays) is anopen protocol for decentralized message transmission, with the intention to be able to resistinternet censorship[2] while maintainingsession integrity. "Noster" can also be translated as "our" or "ours" from Latin. The protocol achieves decentralization through users publishing content associated with acryptographic public key to various "relays", which areWebSocket servers that store and distribute anactivity stream of received data from users. This allows the network to verify users and achieve account portability on Nostr, as users have tosign all posts using their secret key, preventing any relay from tampering with content without invalidating the signature.[3]
The Nostr protocol was first written in 2020 by a Brazilianopen source developer known by the pseudonym "fiatjaf" as a response to perceived moderation issues on Twitter, as well as both technical and cultural disagreements with other protocols such asActivityPub andSecure Scuttlebutt.[4][5] In 2024, in an article reporting on the project's funding,Business Insider claimed to have identified fiatjaf, and had found two websites previously published by this person to disseminate the work ofOlavo de Carvalho, a far-right conspiracy theorist.[4]
Nostr is anopen standard, and the majority of third-party apps which utilities Nostr arefree and open-source.[6] Data on the Nostr protocol is stored inJSON blobs called Events, which is the only kind of object on the Nostr protocol.[7][3] Users are identified by their public key, tagged as an "npub" key. Different extensions to the Nostr protocol are called Nostr Implementation Possibilities, or "NIPs".[8] One of these extensions provide integration with theLightning Network, a separate payment protocol that operates over theBitcoin network, allowing Nostr users to send and request small payments (nicknamed "Zaps") among other users.[9] Other NIPs include ways to add a human-readable alias to an npub key using awell-known URI hosted on a web server, a method that is used by other protocols suchActivityPub and theAT Protocol.[non-primary source needed]
As a result of its ability to quickly and discreetly create accounts and publish posts to relays, Nostr can propagatespam much more easily if left unchecked. A notable example includes a case where multipleprotocol bridges have been used to conduct spam waves on theBluesky social network (itself connected to a competing protocol, the AT Protocol) by creating posts on Nostr, bridging the post toActivityPub and bridging it again to Bluesky.[10]
The Nostr client Damus is amicrobloggingsocial networking app akin toTwitter.[11][12] Damus was the first Nostr app to be listed on theApp Store.[13] Two days after it was launched in February 2023, Damus was removed from the Chinese version of theApp Store per a directive from theCyberspace Administration of China.[14]
Nostr is primarily popular withcryptocurrency users, primarilyBitcoin users.[13]Jack Dorsey, the co-founder ofTwitter, has endorsed and financially supported the development of Nostr by donating approximately $250,000 worth of Bitcoin to the developers of the project in 2023,[13][15] as well as a $10 million cash donation to a Nostr development collective in 2025.[16][4]
As of May 2023, the protocol was reported to have over 18 million registered users across its network.[5]