Easily build your customized Nostr Relay.
I think examples are the best way to explain how to use this library.
import { NostrRelay, createOutgoingNoticeMessage } from '@nostr-relay/core';
import { EventRepositorySqlite } from '@nostr-relay/event-repository-sqlite';
import { Validator } from '@nostr-relay/validator';
import { WebSocketServer } from 'ws';
async function bootstrap() {
const wss = new WebSocketServer({ port: 4869 });
// You can implement your own event repository. It just needs to implement a few methods.
const eventRepository = new EventRepositorySqlite();
await eventRepository.init();
const relay = new NostrRelay(eventRepository);
const validator = new Validator();
wss.on('connection', ws => {
// Handle a new client connection. This method should be called when a new client connects to the Nostr Relay server.
relay.handleConnection(ws);
ws.on('message', async data => {
try {
// Validate the incoming message.
const message = await validator.validateIncomingMessage(data);
// Handle the incoming message.
await relay.handleMessage(ws, message);
} catch (error) {
if (error instanceof Error) {
ws.send(JSON.stringify(createOutgoingNoticeMessage(error.message)));
}
}
});
// Handle a client disconnection. This method should be called when a client disconnects from the Nostr Relay server.
ws.on('close', () => relay.handleDisconnect(ws));
ws.on('error', error => {
ws.send(JSON.stringify(createOutgoingNoticeMessage(error.message)));
});
});
}
bootstrap();Full API documentation can be found here
You can create your own plugin to extend the functionality of the Nostr Relay. A plugin is just an object containing some of the following methods:
This method functions like Koa middleware and is called when a new message is received from a client.
Params:
ctx: The context object of the client.message: The incoming message.next: The next function to call the next plugin.
Example:
import { HandleMessagePlugin } from '@nostr-relay/common';
class MessageLoggerPlugin implements HandleMessagePlugin {
async handleMessage(ctx, message, next) {
const startTime = Date.now();
console.log('Received message:', message);
const result = await next();
console.log('Message processed in', Date.now() - startTime, 'ms');
return result;
}
}
relay.register(new MessageLoggerPlugin());This method will be called before handling an event. If the method returns false, the event will be ignored.
params:
event: The incoming event.
Example:
import { HandleMessagePlugin } from '@nostr-relay/common';
class BlacklistGuardPlugin implements BeforeHandleEventPlugin {
private blacklist = [
// ...
];
beforeHandleEvent(event) {
const canHandle = !this.blacklist.includes(event.pubkey);
return {
canHandle,
message: canHandle ? undefined : 'block: you are blacklisted',
};
}
}
relay.register(new BlacklistGuardPlugin());This method functions like Koa middleware and is called when an event is broadcast.
Params:
event: The event to broadcast.next: The next function to call the next plugin.
Example:
import { BroadcastPlugin } from '@nostr-relay/common';
class RedisBroadcastPlugin implements BroadcastPlugin {
async broadcast(event, next) {
await redis.publish('events', JSON.stringify(event));
return next();
}
}
relay.register(new RedisBroadcastPlugin());If you like this project, you can buy me a coffee :) ⚡️ codytseng@getalby.com ⚡️
