var Stealth = require('stealth')

// you get this from the person you're going to pay (receiver)
var addr = 'vJmtuUb8ysKiM1HtHQF23FGfjGAKu5sM94UyyjknqhJHNdj5CZzwtpGzeyaATQ2HvuzomNVtiwsTJSWzzCBgCTtUZbRFpzKVq9MAUr'
var stealth = Stealth.fromString(addr)

// single-use nonce key pair, works with CoinKey, bitcoinjs-lib, bitcore, etc
var keypair = require('coinkey').createRandom()

// generate payment address
var payToAddress = stealth.genPaymentAddress(keypair.privateKey)

// create transaction with two outputs:
// 1. Regular pay-to-pubkeyhash with `payToAddress` as recipient
// 2. OP_RETURN with `keypair.publicKey`

var Stealth = require('stealth')

// you need to scan every transaction and look for the following:
// 1. does the transaction contain an OP_RETURN?
// 2. if yes, then extract the OP_RETURN
// 3. is the OP_RETURN data a compressed public key (33 bytes)?
// 4. if yes, check if mine

// generate two key pairs, can use CoinKey, bitcoinjs-lib, bitcore, etc
var payloadKeyPair = require('coinkey').createRandom()
var scanKeyPair = require('coinkey').createRandom()

// note, the private keys are NOT encoded in the Stealth address
// you need to save them somewhere
var stealth = new Stealth({
  payloadPrivKey: payloadKeyPair.privateKey,
  payloadPubKey: payloadKeyPair.publicKey,
  scanPrivKey: scanKeyPair.privateKey,
  scanPubKey: scanKeyPair.publicKey
})

var addr = stealth.toString()
// => 'vJmtuUb8ysKiM1HtHQF23FGfjGAKu5sM94UyyjknqhJHNdj5CZzwtpGzeyaATQ2HvuzomNVtiwsTJSWzzCBgCTtUZbRFpzKVq9MAUr'

// publish addr or give it someone
// unlike regular Bitcoin addresses, you can use
// stealth address as much as you like

// scan and decode transactions

var opReturnPubKey = /* */
var pubKeyHashWithPayment = /* */

var keypair = stealth.checkPaymentPubKeyHash(opReturnPubKey, pubKeyHashWithPayment)

// it NOT YOURS, `keypair` will be falsey

if (keypair == null) {
  console.log('payment is not mine')
} else {
  console.log('payment is mine')

  // redeem with `privKey`
  console.log(keypair.privKey)
}