Makefile

HEDGE = node riphedge
 
all:
	npm install ripple-lib
 
hedge:
	-while date; do \
		$(HEDGE); \
		sleep 100; \
	done
 
clean:
	-rm -fr node_modules

riphedge.js

var ripple = require("ripple-lib");
 
var id = process.env.RIPHEDGE_ID;
var key = process.env.RIPHEDGE_KEY;
 
var west = {
	host: "s_west.ripple.com",
	port: 443,
	secure: true
};
 
var east = {
	host: "s_east.ripple.com",
	port: 443,
	secure: true
};
 
var options = {
	fee_cushion: 1.5,
	servers: [
		east,
		west
	],
	trusted: false
};
 
var remote = new ripple.Remote(options);
 
var delta, xrp;
var issuer, currency, fiat;
var index, ledger;
 
var ratio = 0.02;
 
function start()
{
	console.log("Connected");
	remote.set_secret(id, key);
	wait();
}
 
function wait()
{
	console.log("Wait for ledger to close");
	remote.on("ledger_closed", update);
}
 
function update()
{
	remote.removeListener("ledger_closed", update);
	remote.request_account_offers(id, index, ledger, check);
}
 
function check(error, response)
{
	var offers;
 
	if (error) {
		console.log("Failed to get offers");
		return wait();
	}
 
	offers = response.offers;
	if (!offers.length) {
		console.log("No offers");
		remote.request_account_info(id, setxrp);
	} else if (1 == offers.length) {
		var transaction = remote.transaction();
 
		console.log("Cancel obsolete offer");
		transaction.offer_cancel(id, offers[0].seq);
		transaction.submit(wait);
	} else {
		console.log("Offers still exist");
		finish();
	}
}
 
function setxrp(error, response)
{
	if (error) {
		console.log("Failed to get balance");
		return wait();
	}
 
	xrp = parseFloat(response.account_data.Balance);
	xrp /= 1e6;
	delta = ratio * xrp;
	console.log("Ripples", xrp);
 
	remote.request_account_lines(id, index, ledger, setfiat);
}
 
function setfiat(error, response)
{
	var lines, line;
 
	if (error) {
		console.log("Failed to get lines");
		return wait();
	}
 
	lines = response.lines;
	if (1 != lines.length) {
		console.log("Only single currency supported");
		return wait();
	}
 
	line = lines[0];
	issuer = line.account;
	currency = line.currency;
	fiat = parseFloat(line.balance);
	console.log("Fiat", fiat, currency, issuer);
 
	bid();
}
 
function bid()
{
	var transaction = remote.transaction();
 
	var price = (xrp - 2 * delta) / fiat;
	var buy = delta / price;
	var sell = delta;
 
	buy = buy.toFixed(6) + currency;
	price = price.toFixed(6);
	console.log("Bid", buy, "@", price);
	buy = ripple.Amount.from_human(buy);
	buy.set_issuer(issuer);
 
	sell = delta.toFixed(6) + "XRP";
	sell = ripple.Amount.from_human(sell);
 
	transaction.offer_create(id, buy, sell);
	transaction.submit(ask);
}
 
function ask()
{
	var transaction = remote.transaction();
 
	var price = (xrp + 2 * delta) / fiat;
	var sell = delta / price;
	var buy = delta;
 
	sell = sell.toFixed(6) + currency;
	price = price.toFixed(6);
	console.log("Ask", sell, "@", price);
	sell = ripple.Amount.from_human(sell);
	sell.set_issuer(issuer);
 
	buy = delta.toFixed(6) + "XRP";
	buy = ripple.Amount.from_human(buy);
 
	transaction.offer_create(id, buy, sell);
	transaction.set_flags("Sell");
	transaction.submit(finish);
}
 
function finish()
{
	console.log("Disconnect");
	process.exit();
}
 
setTimeout(finish, 1e6);
remote.connect(start);