Quartz

Quartz is a decentralized cash system built like a blockchain, but which stores user data on a webTRC-based graph database to allow for faster queries and light-weight storage.

The app is available here

Table of contents

• Scope
• Features
• Development
  • Setup
  • Install
  • Run
  • Populate with dummy data
  • Deploy
• API
• Sources

Scope

The app was built as a second project during Ironhack's Full Stack Developer bootcamp. It was awarded gold medal for best project by teachers and students.

Features

• User authentication and authorization via Passport
• Password reset via Nodemailer

• Off-chain data stored in a MongoDB database
• On-chain data stored on Gun

• Purchasing QRTZ Coins via Stripe

• Proof of Work algorithm for block mining
• Merkle Tree structure for storing transaction data

Development

Setup

Requirements

• NodeJS: >= 14
• NPM: >= 8.1.2

Config variables

Add the following variable with your own values inside a .env file:

Server-side

• PORT=5005 (local port to call the server)
• ORIGIN=http://localhost:3000 (local URL to call the app)
• MONGODB_URI=mongodb://localhost/quartz (local URL to call the database)
• GMAIL_USER (Gmail address for Nodemailer)
• GMAIL_PWD (Gmail address password)
• STRIPE_PRIV_KEY (private key from your Stripe developer account)

Client-side

• REACT_APP_GUN_URL=http://localhost:5005/gun
• REACT_APP_API_URL=http://localhost:5005/api
• REACT_APP_STRIPE_PUB_KEY (public key from your Stripe developer account)

Install

# install dependencies
$ npm i 

Run

# launch the app in development modeh
$ npm run dev

Populate with dummy data

Server-side

Populate the MongoDB dabatabase with dummy users and wallets with the functions in ./bin/seed.js.

Client-side

Populate the GunJS decentralized database with a dummy blockchain and transactions with the functions in ./client/src/bin/seed.

1. Replace the content of wallets.json with the dummy wallets you have generated on the server-side.

2. Go to the /seed route.

Click on the following buttons:

• Init blockchain instance: creates an instance of the singleton blockchain class in GunJS.
• Top up wallets: generate random transactions to top wallets up and store them on GunJS.
• Verify pending transactions & mine block: select a random wallet to verify current pending transactions and mine them into a block.
• Generate random transactions: generate random transactions between wallets and store them on GunJS.

Check your console for success or failure messages.

Deploy

You must log into Heroku first.

# create an Heroku app in the root directory
$ heroku create -a example-app

# deploy to Heroku
$ git push heroku main

API

POST /signup

Create a new user.

POST /signup
{
  "email": "jdoe@gmail.com",
  "password": "Foobar@01",
  "passwordConfirm": "Foobar@01"
}

Response:

{
  "newUser": {
    "_id": "620d2a6cd7ba8f53a70a75e1",
    "createdAt": "2022-02-16T16:46:36.854+00:00",
    "email": "jdoe@gmail.com"
  }
}

POST /login

Log a user in.

POST /login
{
  "email": "jdoe@gmail.com",
  "password": "Foobar@01"
}

Response:

{
  "userData": {
    "_id": "620d2a6cd7ba8f53a70a75e1",
    "createdAt": "2022-02-16T16:46:36.854+00:00",
    "email": "jdoe@gmail.com"
  },
  "walletAddress": "4cd203f4eb2534875ac1fb365792ad020f87a2fda9633bfd062074ae2e82f9b1"
}

GET /loggedin

Check whether a user is logged in.

Response:

{
  "userData": {
    "_id": "620d2a6cd7ba8f53a70a75e1",
    "createdAt": "2022-02-16T16:46:36.854+00:00",
    "email": "jdoe@gmail.com"
  },
  "walletAddress": "4cd203f4eb2534875ac1fb365792ad020f87a2fda9633bfd062074ae2e82f9b1"
}

Error: 403

{
  "message": "Unauthorized"
}

PUT /:userId

Update a user's account data.

PUT /:userId
{
  "email": "jdoe@gmail.com",
  "password": "Foobar@01",
  "passwordConfirm": "Foobar@01"
}

Response:

{
  "user": {
    "_id": "620d2a6cd7ba8f53a70a75e1",
    "createdAt": "2022-02-16T16:46:36.854+00:00",
    "email": "jdoe@gmail.com"
  }
}

DELETE /:userId

Delete a user's account.

Response:

{
  "message": "Your account has been removed successfully." 
}

POST /wallets

Create a new user wallet.

POST /wallets
{
  "userId": "hfu178387bde190332",
}

Response:

{
  "walletAddress": "4cd203f4eb2534875ac1fb365792ad020f87a2fda9633bfd062074ae2e82f9b1"
}

POST /coins

Add QRTZ Coins to a user's wallet.

POST /coins
{
  "amount": "3000",
  "token": "",
  "keypair": "",
  "publicKey": ""
}

Response:

{
  "amount": "3000",
  "keypair": ""
}

Sources

This project is based on O'Reilly's Mastering Bitcoin.

Available at: https://www.oreilly.com/library/view/mastering-bitcoin/9781491902639/