Goothereum

Copyright 2018 SweetPalma <sweet.palma@yandex.ru>

Own Blockchain in 160 lines of JavaScript - repository for Medium article code: https://medium.com/@sweetpalma/goothereum-blockchain-in-160-lines-of-javascript-8052ca448857

Introduction

Ethereum was released three years ago — and it quickly became a de facto standard of decentralized trust management by introducing a powerful smart contracting platform. Together with its spiritual predecessor Bitcoin it also changed how the financial world works — by introducing a completely new way of sharing funds.

But despite of popularity, the way how blockchain works under the hood is still a mystery for many developers. From my standpoint blockchain solutions seem to be pretty interesting and I want to share my modest knowledge with others — that’s why this repository exists.

Installation & Usage

This is a standalone version of Goothereum - it can be installed with NPM:

npm install sweetpalma/goothereum

And used just as a regular JavaScript library:

const {Wallet, Transaction, Block, Blockchain} = require('goothereum');

Now you can write some simple blockchain interactions:

// Create wallets:
const alice = Wallet.create();
const bob   = Wallet.create();

// Create blockchain and mine first empty reward block:
const chain = new Blockchain();
chain.mine(bob.publicKey);

// Check balance (must be Bob: 50 and Alice: 0):
console.log('Bob:',   chain.baln(bob  .publicKey));
console.log('Alice:', chain.baln(alice.publicKey));

// Mine new block with transaction to Alice:
chain.mine(bob.publicKey, [
    new Transaction({
        from:  bob  .publicKey,
        to:    alice.publicKey,
        value: 15,
        nonce: 0,
    }).sign(bob.privateKey),
]);

// Check balance again (must be Bob: 85 and Alice: 15):
console.log('Bob:',   chain.baln(bob  .publicKey));
console.log('Alice:', chain.baln(alice.publicKey));

Keep in mind that Goothereum was made to demonstrate basic blockchain principles and is not even near to be any kind of production-ready product. Use it for educational purposes only.

License

Goothereum is licensed under the MIT License, what allows you to use it for basically anything absolutely for free. It would be great if somebody will find it useful.