Posted on May 12, 2020

Journey into Web Monetization - day 3

After the first day of idea generation and the second day of learning, I thought I'd get into the more practial side of it and try to get something up to play around with.

Here's what I did:

Connect to a Interledger testnet with moneyd
Create an ILP stream server to connect to the moneyd instance.
Generate stream credentials and send money

Run npx moneyd local to start the moneyd instance with a local testnet.

Next, set up a simple node project:

npm init -y npm i -S ilp-protocol-stream ilp-plugin @interledger/connection-tag-utils mkdir src touch src/index.js

// src/index.js const { randomBytes } = require("crypto"); const { createServer, createConnection } = require("ilp-protocol-stream"); const { encode, decode } = require("@interledger/connection-tag-utils"); const createPlugin = require("ilp-plugin"); // Used for encoding and decoding connectionTag const SECRET_KEY = randomBytes(32); async function createStreamServer() { const server = await createServer({ plugin: createPlugin() }); server.on("connection", (connection) => { // connectionTag contains encrypted data, in this case about the user account const { account } = JSON.parse( decode(SECRET_KEY, connection.connectionTag) ); connection.on("stream", (stream) => { stream.setReceiveMax(10000); stream.on("money", (amount) => { console.log(`Received payment from ${account} for: ${amount}`); }); }); }); return server; } async function sendMoney({ amount, destinationAccount, sharedSecret }) { const connection = await createConnection({ plugin: createPlugin(), destinationAccount, sharedSecret, }); const stream = connection.createStream(); await stream.sendTotal(amount); await connection.end(); } async function run() { const server = await createStreamServer(); // Encode the user account here so we can use when we receive money const data = encode(SECRET_KEY, JSON.stringify({ account: "userAccountId" })); const { destinationAccount, sharedSecret } = server.generateAddressAndSecret( data ); const amount = 10000; await sendMoney({ amount, destinationAccount, sharedSecret }); await server.close(); } run().catch((err) => console.log(err));

And finally run it:

npx nodemon src/index.js Received payment from userAccountId for: 10000

Plugins such as ilp-plugin determines where the server connects. It looks for env variable ILP_BTP_SERVER and defaults to btp+ws://localhost:7768 if not found. This is the local moneyd instance.
Data such as information about user or invoice can be encoded in the connectionTag. This will allow us to update databases for example.
To create a stream client and send money we need: destinationAccount and sharedSecret which we can get from a server.