soulinmau/ilp

ILP client for browsers/Node.js

ILP

The Javascript client library for Interledger

The ILP module includes:

• Simple Payment Setup Protocol Version 1 (SPSPv1), a higher level interface for sending ILP payments, which requires the receiver to have an SPSP server.
• Pre-Shared Key Version 1 (PSKv1) Transport Protocol, a non-interactive protocol in which the sender creates the payment details and uses a shared secret to generate the conditions
• Interledger Payment Request Version 2 (IPRv2) Transport Protocol, an interactive protocol in which the receiver specifies the payment details, including the condition
• Interledger Quoting and the ability to send through multiple ledger types using Ledger Plugins

Installation

`npm install --save ilp ilp-plugin

Note that ledger plugins must be installed alongside this module.

Simple Payment Setup Protocol Version 1 (SPSPv1)

If you are sending to an SPSPv1 receiver with a [email protected] identifier, the SPSPv1 module provides a high-level interface:

'use strict'

const SPSP = require('ilp').SPSP
const Plugin = require('ilp-plugin')

const plugin = new Plugin()

;(async function () {
  await plugin.connect()
  console.log('plugin connected')

  const payment = await SPSP.quote(plugin, {
    receiver: '[email protected]',
    sourceAmount: '1'
  })

  console.log('got SPSP payment details:', payment)

  // we can attach an arbitrary JSON object to the payment if we want it
  // to be sent to the receiver.
  payment.memo = { message: 'hello!' }

  await SPSP.sendPayment(plugin, payment)
  console.log('receiver claimed funds!')
})()

Pre-Shared Key Version 1 (PSKv1) Transport Protocol

This is a non-interactive protocol in which the sender chooses the payment amount and generates the condition without communicating with the recipient.

PSK uses a secret shared between the sender and receiver. The key can be generated by the receiver and retrieved by the sender using a higher-level protocol such as SPSP, or any other method. In the example below, the pre-shared key is simply passed to the sender inside javascript.

When sending a payment using PSK, the sender generates an HMAC key from the PSK, and HMACs the payment to get the fulfillment, which is hashed to get the condition. The sender also encrypts their optional extra data using AES. On receipt of the payment, the receiver decrypts the extra data, and HMACs the payment to get the fulfillment.

In order to receive payments using PSK, the receiver must also register a reviewPayment handler. reviewPayment is a callback that returns either a promise or a value, and will prevent the receiver from fulfilling a payment if it throws an error. This callback is important, because it stops the receiver from getting unwanted funds.

PSK Sending and Receiving Example

'use strict'

const uuid = require('uuid')
const ILP = require('ilp')
const PluginBtp = require('ilp-plugin-btp')

const sender = new PluginBtp({
  server: 'btp+wss://:[email protected]'
})

const receiver = new PluginBtp({
  server: 'btp+wss://:[email protected]'
})

;(async function () {
  // --- RECEIVER START ---
  await receiver.connect()

  const receiverSecret = Buffer.from('secret_seed')

  const listener = await ILP.PSK.listen(receiver, { receiverSecret }, (params) => {
    console.log('got transfer:', params.transfer)

    console.log('fulfilling.')
    return params.fulfill()
  })

  console.log('receiver connected')

  // Note the user of this module must implement the method for
  // communicating sharedSecret and destinationAccount from the recipient
  // to the sender
  const { sharedSecret, destinationAccount } = listener.generateParams()
  // --- RECEIVER END ---

  // --- SENDER START ---
  // the sender can generate these, via the sharedSecret and destinationAccount
  // given to them by the receiver.
  const { packet, condition } = ILP.PSK.createPacketAndCondition({
    sharedSecret,
    destinationAccount,
    destinationAmount: '10', // denominated in the ledger's base unit
  })

  const quote = await ILP.ILQP.quoteByPacket(sender, packet)
  console.log('got quote:', quote)

  await sender.sendTransfer({
    id: uuid(),
    to: quote.connectorAccount,
    amount: quote.sourceAmount,
    expiresAt: quote.expiresAt,
    executionCondition: condition,
    ilp: packet
  })

  sender.on('outgoing_fulfill', (transfer, fulfillment) => {
    console.log(transfer.id, 'was fulfilled with', fulfillment)
    stopListening()
  })
  // --- SENDER END ---
})()

Interledger Payment Request Version 2 (IPRv2) Transport Protocol

This protocol uses recipient-generated Interledger Payment Requests, which include the condition for the payment. This means that the recipient must first generate a payment request, which the sender then fulfills.

This library handles the generation of payment requests, but not the communication of the request details from the recipient to the sender. In some cases, the sender and receiver might be HTTP servers, in which case HTTP would be used. In other cases, they might be using a different medium of communication.

IPR Sending and Receiving Example

'use strict'

const uuid = require('uuid')
const ILP = require('ilp')
const PluginBtp = require('ilp-plugin-btp')

const sender = new PluginBtp({
  server: 'btp+wss://:[email protected]'
})

const receiver = new PluginBtp({
  server: 'btp+wss://:[email protected]'
})

;(async function () {
  const stopListening = await ILP.IPR.listen(receiver, {
    receiverSecret: Buffer.from('secret', 'utf8')
  }, async function ({ transfer, fulfill }) {
    console.log('got transfer:', transfer)

    console.log('claiming incoming funds...')
    await fulfill()
    console.log('funds received!')
  })

  // `ipr` is a buffer with the encoded IPR
  const ipr = ILP.IPR.createIPR({
    receiverSecret: Buffer.from('secret', 'utf8'),
    destinationAccount: receiver.getAccount(),
    // denominated in the ledger's base unit
    destinationAmount: '10',
  })

  // Note the user of this module must implement the method for communicating
  // packet and condition from the recipient to the sender.

  // In practice, The rest of this example would happen on the sender's side.

  const { packet, condition } = ILP.IPR.decodeIPR(ipr)
  const quote = await ILP.ILQP.quoteByPacket(sender, packet)
  console.log('got quote:', quote)

  await sender.sendTransfer({
    id: uuid(),
    to: quote.connectorAccount,
    amount: quote.sourceAmount,
    expiresAt: quote.expiresAt,
    executionCondition: condition,
    ilp: packet
  })

  sender.on('outgoing_fulfill', (transfer, fulfillment) => {
    console.log(transfer.id, 'was fulfilled with', fulfillment)
  })
})()

API Reference

SPSP~query ⇒ Promise.<SpspResponse>

Query an SPSP endpoint and get SPSP details

Kind: inner constant of SPSP Returns: Promise.<SpspResponse> - SPSP SPSP response from server

Param	Type	Description
receiver	String	webfinger account identifier (eg. '[email protected]') or URL to SPSP endpoint.

SPSP~validateSPSPResponse(SPSP)

Validate a server's SPSP response, and throw an error if it's wrong.

Kind: inner method of SPSP

Param	Type	Description
SPSP	Promise.<SpspResponse>	SPSP response from server

SPSP~quote(plugin, params) ⇒ Promise.<SpspPayment>

Quote to an SPSP receiver

Kind: inner method of SPSP Returns: Promise.<SpspPayment> - SPSP payment object to be sent.

Param	Type	Default	Description
plugin	Object		Ledger plugin used for quoting.
params	Object		Quote parameters
params.receiver	String		webfinger account identifier (eg. '[email protected]') or URL to SPSP endpoint.
[params.sourceAmount]	String		source amount to quote. This is a decimal, NOT an integer. It will be shifted by the sending ledger's scale to get the integer amount.
[params.destinationAmount]	String		destination amount to quote. This is a decimal, NOT an integer. It will be shifted by the receiving ledger's scale to get the integer amount.
[params.id]	String	uuid()	id to use for payment. sending a payment with the same id twice will be idempotent. If left unspecified, the id will be generated randomly.
[params.timeout]	Number	5000	how long to wait for a quote response (ms).
[params.spspResponse]	SpspResponse	SPSP.query(params.receiver)	SPSP response. The receiver endpoint will be queried automatically if this isn't supplied.

SPSP~sendPayment(plugin, payment) ⇒ Promise.<Object> | String

Quote to an SPSP receiver

Kind: inner method of SPSP Returns: Promise.<Object> - result The result of the payment.String - result.fulfillment The fulfillment of the payment.

Param	Type	Description
plugin	Object	Ledger plugin used for quoting.
payment	SpspPayment	SPSP Payment returned from SPSP.quote.

SPSP~SpspPayment : Object

/** Parameters for an SPSP payment

Kind: inner typedef of SPSP Properties

Name	Type	Default	Description
id	id		UUID to ensure idempotence between calls to sendPayment
source_amount	string		Decimal string, representing the amount that will be paid on the sender's ledger.
destination_amount	string		Decimal string, representing the amount that the receiver will be credited on their ledger.
destination_account	string		Receiver's ILP address.
spsp	string		SPSP response object, containing details to contruct transfers.
publicHeaders	Object	{}	public headers for PSK data. The key-value pairs represent header names and values.
headers	Object	{}	headers for PSK data. The key-value pairs represent header names and values.
memo	Object	{}	arbitrary JSON object for additional data.

SPSP~SpspResponse : Object

SPSP query response

Kind: inner typedef of SPSP Properties

Name	Type	Description
destination_account	string	The ILP address which will receive payments.
shared_secret	string	Base64url encoded 16-byte shared secret for use in PSK.
maximum_destination_amount	string	Integer string representing the maximum that the receiver will be willing to accept.
minimum_destination_amount	string	Integer string representing the minimum that the receiver will be willing to accept.
ledger_info	Object	An object containing the receiver's ledger metadata.
ledger_info.currency_code	string	The currency code of the receiver's ledger.
ledger_info.currency_scale	string	The currency scale of the receiver's ledger.
receiver_info	Object	Additional information containing arbitrary fields.

ILQP~quote(plugin, query) ⇒ Promise.<Quote>

Kind: inner method of ILQP

Param	Type	Description
plugin	Object	The LedgerPlugin used to send quote request
query	Object
query.sourceAddress	String	Sender's address
query.destinationAddress	String	Recipient's address
[query.sourceAmount]	String	Either the sourceAmount or destinationAmount must be specified. This value is a string representation of an integer, expressed in the lowest indivisible unit supported by the ledger.
[query.destinationAmount]	String	Either the sourceAmount or destinationAmount must be specified. This value is a string representation of an integer, expressed in the lowest indivisible unit supported by the ledger.
[query.destinationExpiryDuration]	String | Number	Number of seconds between when the destination transfer is proposed and when it expires.

PSK~createPacketAndCondition(params) ⇒ Object

Create a payment request using a Pre-Shared Key (PSK).

Kind: inner method of PSK Returns: Object - Payment request

Param	Type	Default	Description
params	Object		Parameters for creating payment request
params.destinationAmount	String		Amount that should arrive in the recipient's account. This value is a string representation of an integer, expressed in the lowest indivisible unit supported by the ledger.
params.destinationAccount	String		Target account's ILP address
params.sharedSecret	String		Shared secret for PSK protocol
[params.id]	String	uuid.v4()	Unique ID for the request (used to ensure conditions are unique per request)
[params.expiresAt]	String	none	Expiry of request
[params.data]	Buffer		Additional data to include in the request
[params.headers]	Object		Additional headers for private PSK details. The key-value pairs represent header names and values.
[params.publicHeaders]	Object		Additional headers for public PSK details. The key-value pairs represent header names and values.
[params.disableEncryption]	Boolean	false	Turns off encryption of private memos and data
[params.minFulfillRetryWait]	Number	250	Minimum amount of time (in ms) to wait before retrying fulfillment
[params.maxFulfillRetryWait]	Number	1000	Maximum amount of time (in ms) to wait before retrying fulfillment

PSK~generateParams(params) ⇒ PskParams

Generate shared secret for Pre-Shared Key (PSK) transport protocol.

Kind: inner method of PSK

Param	Type	Description
params	Object	Parameters for creating PSK params
params.destinationAccount	String	The ILP address that will receive PSK payments
params.receiverSecret	Buffer	secret used to generate the shared secret and the extra segments of destinationAccount

PSK~listen(plugin, params, callback) ⇒ Object

Listen on a plugin for incoming PSK payments, and auto-generate fulfillments.

Kind: inner method of PSK Returns: Object - Payment request

Param	Type	Default	Description
plugin	Object		Ledger plugin to listen on
params	Object		Parameters for creating payment request
params.sharedSecret	Buffer		Secret to generate fulfillments with
[params.allowOverPayment]	Buffer	false	Accept payments with higher amounts than expected
callback	IncomingCallback		Called after an incoming payment is validated.

PSK~listenAll(factory, params, callback) ⇒ Object

Listen on a ILP plugin bells factory for incoming PSK payments, and auto-generate fulfillments.

Kind: inner method of PSK Returns: Object - Payment request

Param	Type	Default	Description
factory	Object		Plugin bells factory to listen on
params	Object		Parameters for creating payment request
params.receiverSecret	Buffer		secret used to generate the shared secret and the extra segments of destinationAccount
[params.allowOverPayment]	Boolean	false	Accept payments with higher amounts than expected
callback	IncomingCallback		Called after an incoming payment is validated.

PSK~IncomingCallback : function

Kind: inner typedef of PSK

Param	Type	Description
params	Object
params.transfer	Object	Raw transfer object emitted by plugin
params.data	Object	Decrypted data parsed from transfer
params.destinationAccount	String	destinationAccount parsed from ILP packet
params.destinationAmount	String	destinationAmount parsed from ILP packet
params.fulfill	function	async function that fulfills the transfer when it is called

IPR~createPacketAndCondition(params) ⇒ Object

Create a packet and condition

Kind: inner method of IPR Returns: Object - Packet and condition for use in the IPR protocol.

Param	Type	Default	Description
params	Object		Parameters for creating payment request
params.destinationAmount	String		Amount that should arrive in the recipient's account. This value is a string representation of an integer, expressed in the lowest indivisible unit supported by the ledger.
params.destinationAccount	String		Target account's ILP address
params.receiverSecret	Buffer		Secret for generating IPR packets
[params.id]	String	uuid.v4()	Unique ID for the request (used to ensure conditions are unique per request)
[params.expiresAt]	String	60 seconds from now	Expiry of request
[params.data]	Buffer		Additional data to include in the request
[params.headers]	Object		Additional headers for private details. The key-value pairs represent header names and values.
[params.publicHeaders]	Object		Additional headers for public details. The key-value pairs represent header names and values.
[params.disableEncryption]	Boolean	false	Turns off encryption of private memos and data
[params.minFulfillRetryWait]	Number	250	Minimum amount of time (in ms) to wait before retrying fulfillment
[params.maxFulfillRetryWait]	Number	1000	Maximum amount of time (in ms) to wait before retrying fulfillment

IPR~encodeIPR(params) ⇒ Buffer

Create an encoded IPR for use in the IPR transport protocol

Kind: inner method of IPR Returns: Buffer - encoded IPR buffer

Param	Type	Description
params	Object	Parameters for encoding IPR
params.packet	String	ILP packet of this IPR
params.condition	String	condition of this IPR

IPR~decodeIPR(ipr) ⇒ Object

Decode an IPR buffer for use in the IPR transport protocol

Kind: inner method of IPR Returns: Object - Decoded IPR parameters, containing 'packet' and 'condition' as base64url strings.

Param	Type	Description
ipr	Buffer	encoded IPR buffer

IPR~createIPR(params) ⇒ Buffer

Create a payment request for use in the IPR transport protocol.

Kind: inner method of IPR Returns: Buffer - encoded IPR buffer for use in the IPR protocol

Param	Type	Default	Description
params	Object		Parameters for creating payment request
params.destinationAmount	String		Amount that should arrive in the recipient's account. This value is a string representation of an integer, expressed in the lowest indivisible unit supported by the ledger.
params.destinationAccount	String		Target account's ILP address
params.receiverSecret	Buffer		Secret for generating IPR packets
[params.id]	String	uuid.v4()	Unique ID for the request (used to ensure conditions are unique per request)
[params.expiresAt]	String	60 seconds from now	Expiry of request
[params.data]	Buffer		Additional data to include in the request
[params.headers]	Object		Additional headers for private details. The key-value pairs represent header names and values.
[params.publicHeaders]	Object		Additional headers for public details. The key-value pairs represent header names and values.
[params.disableEncryption]	Object	false	Turns off encryption of private memos and data

IPR~listen(plugin, params, callback) ⇒ Object

Listen on a plugin for incoming IPR payments, and auto-generate fulfillments.

Kind: inner method of IPR Returns: Object - Payment request

Param	Type	Default	Description
plugin	Object		Ledger plugin to listen on
params	Object		Parameters for creating payment request
params.secret	Buffer		Secret to generate fulfillments with
[params.allowOverPayment]	Buffer	false	Accept payments with higher amounts than expected
callback	IncomingCallback		Called after an incoming payment is validated.

IPR~listenAll(factory, params, callback) ⇒ Object

Listen on a ILP plugin bells factory for incoming IPR payments, and auto-generate fulfillments.

Kind: inner method of IPR Returns: Object - Payment request

Param	Type	Default	Description
factory	Object		Plugin bells factory to listen on
params	Object		Parameters for creating payment request
params.generateReceiverSecret	function		function that returns receiver secret for a given username
[params.allowOverPayment]	Boolean	false	Accept payments with higher amounts than expected
callback	IncomingCallback		Called after an incoming payment is validated.

IPR~IncomingCallback : function

Kind: inner typedef of IPR

Param	Type	Description
params	Object
params.transfer	Object	Raw transfer object emitted by plugin
params.data	Object	Decrypted data parsed from transfer
params.destinationAccount	String	destinationAccount parsed from ILP packet
params.destinationAmount	String	destinationAmount parsed from ILP packet
params.fulfill	function	async function that fulfills the transfer when it is called