Follow payments sent to an account (Node.js)

This tutorial shows how easy it is to watch for incoming payments on an account using javascript and EventSource. We will eschew using js-stellar-lib, the high-level helper library, to show that it is possible for you to perform this task on your own, with whatever programming language you would like to use.

This tutorial assumes that you:

• Have node.js installed locally on your machine.
• Have curl installed locally on your machine.
• Are running on Linux, OS X, or any other system that has access to a bash-like shell.
• Are familiar with launching and running commands in a terminal.

In this tutorial we will learn:

• How to create a new account.
• How to fund your account using friendbot
• How to follow payments to your account using EventSource and Server-Sent Events.

Project Skeleton

Let’s get started by building our project skeleton:

$ mkdir follow_tutorial
$ cd follow_tutorial
$ npm install --save stellar-base
$ npm install --save eventsource

This should have created a package.json in the follow_tutorial directory. You can check that everything went well by running the following command:

$ node -e "require('stellar-base')"

Everything was successful if no output it generated from the above command. Now let’s write a script to create a new account.

Creating an account

Create a new file named make_account.js and paste the following text into it:

var Keypair = require("stellar-base").Keypair;

var newAccount = Keypair.random();

console.log("New account created!");
console.log("  Address: " + newAccount.address());
console.log("  Seed: " + newAccount.seed());

Save the file and run it:

$ node make_account.js
New account created!
  Address: gxk31VU4jeBBtdkUo4YKqCnd66iavjKvn36m1o7W95WtJfPW1g
  Seed: s3SK8u5ghRvPmPNatUcCg8jCC4wbuYoBtZKnWjsxDRRn857Yrvc
$  

Before our account can do anything it must be funded. Indeed, before an account is funded it does not truly exist!

Funding your account

The Stellar test network provides a currency faucet that provides free lumens for developers call Friendbot. To fund you account, you simply execute the following curl command:

$ curl https://horizon-testnet.stellar.org/friendbot?addr=gxk31VU4jeBBtdkUo4YKqCnd66iavjKvn36m1o7W95WtJfPW1g

Don’t forget to replace the address above with your own. If the request succeeds, you should see a response like:

{
"hash": "ed9e96e136915103f5d8978cbb2036628e811f2c59c4c3d88534444cf504e360",
"result": "received",
"submission_result": "000000000000000a0000000000000001000000000000000000000000"
}

After a few seconds, the Stellar network will perform consensus, close the ledger, and your account will have been created. Next up we will write a script that watches for new payments to your account and outputs a message to the terminal.

Following payments

TODO

Testing it out

TODO