How does Nostr work?

• There are two components: clients and relays. Each user runs a client. Anyone can run a relay.
• Every user is identified by a public key. Every post is signed. Every client validates these signatures.
• Clients fetch data from relays of their choice and publish data to other relays of their choice. A relay doesn’t talk to another relay, only directly to users.
• For example, to “follow” someone a user just instructs their client to query the relays it knows for posts from that public key.
• On startup, a client queries data from all relays it knows for all users it follows (for example, all updates from the last day), then displays that data to the user chronologically.
• A “post” can contain any kind of structured data, but the most used ones are going to find their way into the standard so all clients and relays can handle them seamlessly.

How does it solve the problems the current social can’t?

• Users getting banned and servers being closed
  • A relay can block a user from publishing anything there, but that has no effect on them as they can still publish to other relays. Since users are identified by a public key, they don’t lose their identities and their follower base when they get banned.
  • Instead of requiring users to manually type new relay addresses (although this should also be supported), whenever someone you’re following posts a server recommendation, the client should automatically add that to the list of relays it will query.
  • If someone is using a relay to publish their data but wants to migrate to another one, they can publish a server recommendation to that previous relay and go;
  • If someone gets banned from many relays such that they can’t get their server recommendations broadcasted, they may still let some close friends know through other means with which relay they are publishing now. Then, these close friends can publish server recommendations to that new server, and slowly, the old follower base of the banned user will begin finding their posts again from the new relay.
  • All of the above is valid too for when a relay ceases its operations.
• Censorship-resistance
  • Each user can publish their updates to any number of relays.
  • A relay can charge a fee (the negotiation of that fee is outside of the protocol for now) from users to publish there, which ensures censorship-resistance (there will always be some Russian server willing to take your money in exchange for serving your posts).
• Spam
  • If spam is a concern for a relay, it can require payment for publication or some other form of authentication, such as an email address or phone, and associate these internally with a pubkey that then gets to publish to that relay — or other anti-spam techniques, like hashcash or captchas. If a relay is being used as a spam vector, it can easily be unlisted by clients, which can continue to fetch updates from other relays.
• Data storage
  • For the network to stay healthy, there is no need for hundreds of active relays. In fact, it can work just fine with just a handful, given the fact that new relays can be created and spread through the network easily in case the existing relays start misbehaving. Therefore, the amount of data storage required, in general, is relatively less than Mastodon or similar software.
  • Or considering a different outcome: one in which there exist hundreds of niche relays run by amateurs, each relaying updates from a small group of users. The architecture scales just as well: data is sent from users to a single server, and from that server directly to the users who will consume that. It doesn’t have to be stored by anyone else. In this situation, it is not a big burden for any single server to process updates from others, and having amateur servers is not a problem.
• Video and other heavy content
  • It’s easy for a relay to reject large content, or to charge for accepting and hosting large content. When information and incentives are clear, it’s easy for the market forces to solve the problem.
• Techniques to trick the user
  • Each client can decide how to best show posts to users, so there is always the option of just consuming what you want in the manner you want — from using an AI to decide the order of the updates you’ll see to just reading them in chronological order.

Nostr enables you to move between server relays or use multiple relays but if these relays are just on AWS or Azure what’s the difference?

There are literally thousands of VPS providers scattered all around the globe today, there is not only AWS or Azure. AWS or Azure are exactly the providers used by single centralized service providers that need a lot of scale, and even then not just these two. For smaller relay servers any VPS will do the job very well.

What incentive is there for people to run relays?

The question is misleading. It assumes that relays are free dumb pipes that exist such that people can move data around through them. In this case yes, the incentives would not exist. This in fact could be said of DHT nodes in all other p2p network stacks: what incentive is there for people to run DHT nodes?