@z-torrent/lsd

Local Service Discovery (BEP14)

Node.js implementation of BEP 14 — a SSDP-like mechanism (HTTP over UDP multicast) to announce participation in torrent swarms on the local network.

Used by Z-Torrent discovery.

Install

npm install @z-torrent/lsd

Usage

import { LSD } from '@z-torrent/lsd'
import crypto from 'crypto'

const opts = {
  peerId: crypto.randomBytes(20), // hex string or Uint8Array (e.g. Buffer)
  infoHash: crypto.randomBytes(20),
  port: 51413, // torrent client listen port
}

const lsd = new LSD(opts)

lsd.start()

lsd.on('peer', (peerAddress, infoHash) => {
  console.log('peer:', peerAddress, 'infoHash:', infoHash)
})

lsd.destroy()

API

new LSD(opts)

• opts.peerId — required, string or Uint8Array (20-byte id, hex string if string)
• opts.infoHash — required, string or Uint8Array (40-char hex or 20 raw bytes)
• opts.port — required, client port as number or string

lsd.start()

Binds the multicast socket, joins the group, sends an announce, then repeats every 5 minutes.

lsd.destroy([callback])

Closes the socket and clears the announce interval. Optional callback runs when the socket has closed.

lsd.destroyed

Read-only: whether destroy() has been called.

Events

peer

(peerAddress, infoHash) — peerAddress is host:port; infoHash is the 40-character hex string from the announce.

warning

Non-fatal issues (invalid remote message, multicast join failure, etc.). Payload may be a string or other value.

error

Fatal socket errors.

License

MIT