early alpha. the example works, but no tests are written yet. Also the PQueueAdapter is not yet implemented.

nostrawl

Trawl [/trɔːl/]

1. an act of fishing with a trawl net or seine.
2. a thorough search.

nostrawl is a simple tool for persistently fetching and processing filtered events from a set of nostr relays.

nostrawl wraps nostr-fetch (with the nostr-tools simple-pool adapter) and implements adapters for queuing fetch jobs. Implements an LMDB cache that can be accessed via provided parser and validator functions.

Install

pnpm install @nostrwatch/nostrawl

npm package soon

Run Example

With docker

pnpm run example

With a local redis instance. Use defaults, or set with envvars (REDIS_HOST, REDIS_PORT, etc)

node examples/bullmq/index.js

Note: This example is for demonstration purposes only, the example will likely hit memory limits if left running too long

Run Tests

What tests?

Docs

I'll write docs once there are tests, both adapters are implemented and there is demand.

Queue Adapters

• BullMQAdapter: Redis-based queue adapter
• PQueueAdapter: Process-bound queue adapter

Usage

import { nostrawl } from 'nostrawl'
import dotenv from 'dotenv'
dotenv.config()

const relays = ["wss://relay.damus.io","wss://nostr-pub.wellorder.net","wss://nostr.mom","wss://nostr.slothy.win","wss://global.relay.red"]

const options = {
  filters: { kinds: [3] },
  adapter: 'bullmq',
  queueName: 'ContactLists',
  repeatWhenComplete: true,
  restDuration: 60*60*1000,
  strictTimestamps: true,
  relaysPerBatch: 3,
  since: Math.round(Date.now()/1000-(60*60)),
  nostrFetchOptions: {
    sort: true
  },
  adapterOptions: {
    redis: {
      host: process.env.REDIS_HOST || 'localhost',
      port: process.env.REDIS_PORT || 6379, 
      db: process.env.REDIS_DB || 0 
    }
  },
  queueOptions: {
    removeOnComplete: true, 
    removeOnFail: true
  },
  //the cache is used internal to remember the last time 
  //a relay was filtered against, so it can resume from
  //there later. It uses to the key `lastUpdate:${timestamp}`
  //so be weary of that. 
  parser: async ($trawler, event) => {
    $trawler.cache.put(`found:${event.id}`)
  },
  validator: ($trawler, event) => {
    if($trawler.cache.get(`found:${event.id`))
      return false 
    return true
  } 
}

const trawler = nostrawl(relays, options)

trawler
  .on_worker('progress', (job, progress) => console.log(`[@${progress.last_timestamp}] ${progress.found} events found and ${progress.rejected} events rejected from  ${progress.relay}`))
  .on_queue('drained', () => console.log(`queue is empty`))
  .on_worker('completed', (job) => console.log(`${job.id} completed`))

trawler.run()