Folks who trade used luxury watches know how important it is for your watch to come with a certificate. Typically in the form of a credit card-sized plastic or a folded piece of paper with a serial number, the name of the first owner, and the date of purchase, the watch certificate is an important determinant of the watch’s resale value.

This is so because of authenticity. By matching the serial number stated on the certificate and the serial number engraved on the watch case, a buyer will be relatively well assured that the watch is authentic. …


Why a Freelancer’s Smart Contract?

I began my career building software for companies as a freelancer in my teens back in the late 90s. It was the best, or worst of times depending on how you see it. Apart from honing my development skills, I learned how to price my service and negotiate terms of payments so that I would be paid in stages as I delivered codes. These were skills I kept dear and near till today.

But it certainly wasn’t easy. There was one project that I completed just before I was sent away on 10 weeks’ military training. As a result, it…


How do you ensure that the Non-Fungible Token (NFT) that you just bought will definitely be delivered?

Let’s take this question further.

Imagine that you are purchasing a used luxury watch that comes with an ERC-721 based NFT certificate (like the one that I discussed in the article NFT-based Luxury Watch Certificate). How do both the buyer and seller ensure payment and delivery without a middleman?

Photo by Nicolas Cool on Unsplash

In this series, I propose how an NFT Escrow Service Smart Contract may make peer-to-peer trading of NFTs or physical goods such as luxury watches safe and secure.

The source codes for this project…


A Decentralized App for Minting, Viewing, and Transferring NFT-based Certificate of Authenticity for Luxury Watches

This is the 2nd part of my series of articles to demonstrate how Non-Fungible Tokens (NFTs) may replace paper-based Certificate of Authenticity for luxury goods such as watches.

Photo by Pierre Bamin on Unsplash

Refer to Part 1 to learn the business logic behind how this may work.

I name my imaginary watchmaker BreitLex. In this article, I will demonstrate how BreitLex and watch buyers will use BrietLex’s Decentralized App to mint and transfer NFT-based Certificates of Authenticity.

Architecture


Building & Deploying an Ethereum Decentralized App

Welcome back!

This is the 2nd of a 2-part tutorial I will walk through my Ethereum Development toolchain using the example of building the Freelancer Decentralized Application:

  1. Writing and Testing the Solidity Smart Contract
  2. Building and Deploying the DApp

The scripts and config files that I use for this tutorial can be found in my GitHub repository here

In this part of the tutorial, we shall focus on building and deploying our Freelancer Decentralized App to run on the Glitch platform (free!).

Photo by Fotis Fotopoulos on Unsplash

package.json

I developed the Freelancer Decentralized App (DApp) using Vanilla JavaScript and Bootstrap 5. Refer to my package.json


My Ethereum Development Toolchain

Like all other software development processes, building Decentralized Applications in Ethereum comes with its suite of development tools. In fact, there are many options.

In this 2-part tutorial I will walk through my Ethereum Development toolchain using the example of building the Freelancer Decentralized Application:

  1. Writing and Testing the Solidity Smart Contract
  2. Building and Deploying the DApp

The scripts and config files that I use for this tutorial can be found in my GitHub repository here

There are many ways to build a DApp, and here’s mine.

Photo by Alexandru Acea on Unsplash

Ganache

Ganache is a desktop-based personal Ethereum Blockchain. A local, self-contained Ethereum Blockchain network…


This is the 2nd part of a 4-part series that document my process of building a Decentralized Application (DApp) for freelancers to receive multiple partial payments for a project that he undertakes with a client.

Photo by Cathryn Lavery on Unsplash

For a step-by-step guide on the business logic of this process, refer to part 1 of this series. The source codes for the project can be found in the project’s Github repository.

In the second part of this series, I will walk through the Decentralized Applications that let the programmer and his client arrange payments, pay, and get paid in ETHs.

How It Works

There…


This series of tutorial documents my process of building an Ethereum faucet on the Ropsten Testnet. This is the 4th article of the series and it explains the codes behind the Faucet Web App. The Faucet Web App allows requesters to provide their Wallet address to let the faucet dish out free ETH to them.

  1. Ropsten Ethereum Faucet: How it works
  2. Ropsten Ethereum Faucet: Smart Contract
  3. Ropsten Ethereum Faucet: JSON Web Service
  4. Ropsten Ethereum Faucet: Web App

The source codes for this project are in the project’s Github repository and the faucet smart contract is accessible here.

Photo by Kirsten Marie Ebbesen on Unsplash

Not a DApp


This series of tutorial documents my process of building an Ethereum faucet on the Ropsten Testnet. This is the 3rd article of the series and it explains the codes behind the JSON Web Service. The JSON Web Service performs the role of dishing out free ETH when the requester provides his Ethereum wallet address and the number of ETHs he wishes to receive.

  1. Ropsten Ethereum Faucet: How it works
  2. Ropsten Ethereum Faucet: Smart Contract
  3. Ropsten Ethereum Faucet: JSON Web Service
  4. Ropsten Ethereum Faucet: Web App

The source codes for this project are in the project’s Github repository and the faucet…


Motivation

This series of tutorial documents my process of building an Ethereum faucet on the Ropsten Testnet. This is the 2nd article of the series and it explains how the Faucet Smart Contract works.

Photo by Zbysiu Rodak on Unsplash
  1. Ropsten Ethereum Faucet: How it works
  2. Ropsten Ethereum Faucet: Smart Contract
  3. Ropsten Ethereum Faucet: JSON Web Service
  4. Ropsten Ethereum Faucet: Web App

The source codes for this project are in the project’s Github repository and the faucet smart contract is accessible here.

Discover and review best Ethereum development tools

Setting up the Faucet Smart Contract

Jackson Ng

Changing the world, one semicolon at a time @ http://jacksonng.org

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