Krave

A React app for scheduled Cash Account registrations.

Overview

Cash Accounts are basically aliases for BCH addresses and the numbers increment infinitely based on each block that gets mined on the Bitcoin Cash network. Krave follows the spec to create cash accounts.

How it works

Each registration is saved into the database along with the specified blockheight at which to broadcast/register the cash account. A check is made to ensure there is fewer than 25 queued jobs for each block height. This is due to a current unconfirmed chain limit in the Bitcoin protocol. More than 25 unconfirmed transactions in the mempool results in unreliable confirmations and may result in failing to confirm for the specified blockheight and missing the registration.

A unique identifier is created and a deposit address is generated for each visitor. Once the QR code and deposit address is generated, a socket listener starts listening to all transactions and waits until there is a transaction detected for the newly generated receiving address. Once there is a match, we check the value of the unspent outputs to ensure the proper amount was sent.

If the value is correct, a callback will insert the job into the database to be registered at a later block height. A button to pay with the BadgerWallet is also included for convenience. If the user has Badger installed with funds, the transaction can be completed in seconds with just 2 clicks.

A scheduler runs every minute to check for queued jobs. There cannot be duplicate registration transaction IDs so a malicious user cannot spoof/insert invalid jobs into the database. A valid job to be processed requires a valid txid (to confirm it was paid for), and is marked complete once the registration transaction is broadcasted. That registration txid is saved to the database as well.

Project Organization

src is where most of the logic lies

src/routes where all the express/api routes is handled

src/classes classes/services, and bulk of logic.

public for all assets that are not sensitive. logos, images, etc.

Quick Start

cd to Krave directory
npm run start

browse to http://localhost:4545

testing

npm run test

Tested on Node v8.9.3

you can read more about Cash Accounts here.