Interledger Lightning Plugin


:rotating_light: Expect breaking changes while this plugin is in beta.

Overview

ilp-plugin-lightning enables settlements between Interledger peers using the Lightning Network on Bitcoin. Using the ILP/Stream protocol, payments are chunked down into small increments, which can facilitate faster and more relaible payments compared with native Lightning!

The integration requires an existing Lightning node with connectivity to the greater Lightning network. Note that speed within the Lightning network degrades as two peers have more degrees of separation, and opening a direct channel provides a much faster experience.

Additional information on the Lightning Network is available here.

Install

``bash
npm install ilp-plugin-lightning
`

Requires Node.js 10+.

API

Here are the available options to pass to the plugin. Additional configuration options are also inherited from ilp-plugin-btp if the plugin is a client, and ilp-plugin-mini-accounts if the plugin is a server.

Clients do not settle automatically. Sending Lightning payments can be triggered by invoking sendMoney on the plugin, and the money handler is called upon receipt of incoming payments (set using registerMoneyHandler).

The balance configuration has been simplified for servers. Clients must prefund before sending any packets through a server, and if a client fulfills packets sent to them through a server, the server will automatically settle such that they owe 0 to the client. This configuration was chosen as a default due to it's security and protection against deadlocks.

#### role

- Type:
- "client" to connect to a single counterparty
- "server" enables multiple counterparties to connect
- Default: "client"

#### lnd

- Required
- Type: LndOpts
- Credentials to create a connection to the LND node, or an already constructed LND service

To have the plugin create the connection internally, provide an object with the following properties:

##### macaroon

- Required
- Type: string or Buffer
- LND macaroon to used authenticate daemon requests as a Base64-encoded string or Buffer (e.g. using fs.readFile)

##### tlsCert

- Required
- Type: string or Buffer
- TLS certificate to authenticate the connection to the Lightning daemon as a Base64-encoded string or Buffer (e.g. using fs.readFile)

##### hostname

- Required
- Type: string
- Hostname of the Lightning node

##### grpcPort

- Type: number
- Default: 10009
- Port of LND gRPC server

For example:

`js
{
hostname: 'localhost',
macaroon:
'AgEDbG5kArsBAwoQ3/I9f6kgSE6aUPd85lWpOBIBMBoWCgdhZGRyZXNzEgRyZWFkEgV3cml0ZRoTCgRpbmZvEgRyZWFkEgV32ml0ZRoXCghpbnZvaWNlcxIEcmVhZBIFd3JpdGUaFgoHbWVzc2FnZRIEcmVhZBIFd3JpdGUaFwoIb2ZmY2hhaW4SBHJlYWQSBXdyaXRlGhYKB29uY2hhaW4SBHJlYWQSBXdyaXRlGhQKBXBlZXJzEgRyZWFkEgV3cml0ZQAABiAiUTBv3Eh6iDbdjmXCfNxp4HBEcOYNzXhrm+ncLHf5jA==',
tlsCert:
'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'
}
`

#### maxPacketAmount

- Type: BigNumber, number, or string
- Default: Infinity
- Maximum amount in _satoshis_ above which an incoming ILP packet should be rejected

Bilateral Communication

This plugin uses the Bilateral Transfer Protocol over WebSockets to send messages between peers. Two subprotocols are supported:

#### peeringRequest

- Format: [Identity public key], UTF-8 encoded
- Used for sharing pubkey of our Lightning node with the peer
- Only shares pubkey, does not attempt to peer over the Lightning network

#### paymentRequest`

- Format: BOLT11 encoded, then UTF-8 encoded
- Used to send a invoice to the Interledger peer, so they have the ability to send payments to our instance
- By default, peers send 20 invoices ahead of time, and share an additional invoice as each invoice expires or is paid

Known Issues

- LND does not currently support pruning invoices (neither automatically nor manually). As this plugin may generate several invoices per second when a peer is actively streaming money, this can significantly increase the footprint of the LND database.
- LND may soon support spontaneous payments, which would eliminate the overhead of frequently sharing invoices.
- The plugin does not perform any accounting for Lightning Network fees.