ilp-protocol-psk2

PSKv2

Javascript implementation of the Pre-Shared Key V2 Interledger Transport Protocol.

Features

• End-to-End Quoting
• Single Payments
• Streaming Payments
• (Experimental) Chunked Payments

Installation

npm install ilp-protocol-psk2

API Documentation

See https://emschwartz.github.io/ilp-protocol-psk2

Usage

Creating a Receiver

Uses createReceiver and Receiver.generateAddressAndSecret.

import { createReceiver } from 'ilp-protocol-psk2'
const receiver = await createReceiver({
  plugin: myLedgerPlugin,
  paymentHandler: async (params) => {
    // Accept all incoming payments
    const result = await params.accept()
    console.log('Got payment for:', result.receivedAmount)
  }
})

const { destinationAccount, sharedSecret } = receiver.generateAddressAndSecret()
// Give these two values to a sender to enable them to send payments to this Receiver

Sending a Single Payment

Uses sendSingleChunk and quoteDestinationAmount.

import { sendSingleChunk, quoteDestinationAmount } from 'ilp-protocol-psk2'

// These values must be communicated beforehand for the sender to send a payment
const { destinationAccount, sharedSecret } = await getAddressAndSecretFromReceiver()

const { sourceAmount } = await quoteDestinationAmount(myLedgerPlugin, {
  destinationAccount,
  sharedSecret,
  destinationAmount: '1000'
})

const result = await sendSingleChunk(myLedgerPlugin, {
  destinationAccount,
  sharedSecret,
  sourceAmount,
  minDestinationAmount: '999'
})
console.log(`Sent payment of ${result.sourceAmount}, receiver got ${result.destinationAmount}`)

Sending a Streaming Payment

Uses sendSingleChunk.

import { randomBytes } from 'crypto'
import { sendSingleChunk } from 'ilp-protocol-psk2'

// These values must be communicated beforehand for the sender to send a payment
const { destinationAccount, sharedSecret } = await getAddressAndSecretFromReceiver()

const id = randomBytes(16)
let sequence = 0
const firstChunkResult = await sendSingleChunk(myLedgerPlugin, {
  destinationAccount,
  sharedSecret,
  sourceAmount,
  minDestinationAmount: '0',
  id,
  sequence,
  lastChunk: false
})

// Repeat as many times as desired, incrementing the sequence each time
// Note that the path exchange rate can be determined by dividing the destination amount returned by the chunk amount sent

const lastChunkResult = await sendSingleChunk(myLedgerPlugin, {
  destinationAccount,
  sharedSecret,
  sourceAmount,
  minDestinationAmount: '0',
  id,
  sequence,
  lastChunk: true
})

Experimental Chunked Payments

WARNING: PSK2 Chunked Payments are experimental. Money can be lost if an error occurs mid-payment or if the exchange rate changes dramatically! This should not be used for payments that are significantly larger than the path's Maximum Payment Size.

See sendSourceAmount and sendDestinationAmount.