dat minimal example

index.js

var Swarm = require('discovery-swarm')
var Hyperdrive = require('hyperdrive')
var Level = require('level')

// run this like: node thisfile.js 4c325f7874b4070blahblahetc
// the dat link someone sent us, we want to download the data from it
var link = new Buffer(process.argv[2], 'hex')

// here are the default config dat uses:
// used for MDNS and also as the dns 'app name', you prob shouldnt change this
var DAT_DOMAIN = 'dat.local'
// dat will try this first and pick the first open port if its taken
var DEFAULT_LOCAL_PORT = 3282 
// we run the servers below you can use if you want or run your own
var DEFAULT_DISCOVERY = [
  'discovery1.publicbits.org',
  'discovery2.publicbits.org'
]
var DEFAULT_BOOTSTRAP = [
  'bootstrap1.publicbits.org:6881',
  'bootstrap2.publicbits.org:6881',
  'bootstrap3.publicbits.org:6881',
  'bootstrap4.publicbits.org:6881'
]

var db = Level('./dat.db')
var drive = Hyperdrive(db)
var swarm = Swarm({
  id: drive.core.id,
  dns: {server: DEFAULT_DISCOVERY, domain: DAT_DOMAIN},
  dht: {bootstrap: DEFAULT_BOOTSTRAP},
  stream: function () {
    // this is how the swarm and hyperdrive interface
    console.log('new peer stream')
    return drive.createPeerStream()
  }
})

swarm.once('listening', function () {
  console.log('joining', link)
  // join the swarm
  swarm.join(link)
  // tell hyperdrive to start downloading/uploading in ./data
  var archive = drive.get(link, process.cwd() + '/data')
  archive.ready(function (err) {
    console.log('archive ready')
    // a stream of all metadata. after retrieving each entry metadata will be cached locally
    // but the first time it has to fetch it from the swarm
    var metadata = archive.createEntryStream()
    // start downloading all entries, or choose your own filter logic to download specific entries
    // entries will be either files or directories
    metadata.on('data', function (entry) {
      var dl = archive.download(entry)
      console.log('downloading', entry.name, dl)
      
      dl.on('ready', function () {
        console.log('download started', entry.name, dl)
      })
    })
  })
})

swarm.listen(DEFAULT_LOCAL_PORT)

package.json

{
  "name": "testdat",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "discovery-swarm": "^3.0.0",
    "hyperdrive": "^3.4.1",
    "level": "^1.4.0"
  }
}