Download or read book Build Your First Ethereum DApp written by Bruno Skvorc and published by SitePoint Pty Ltd. This book was released on 2018-08-16 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we'll walk through the creation of a complete distributed application (DApp) based on the Ethereum platform. We'll be building The Neverending Story, a crowdsourced choose-your-own-adventure story with crowd curation and community censorship. This book is for anyone interested in using the Ethereum platform for development. It's advised that you read The Developer's Guide to Ethereum before reading this book if you are not familiar with blockchain technology.

Download or read book Building Ethereum Dapps written by Roberto Infante and published by Simon and Schuster. This book was released on 2019-03-05 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary Building Ethereum Dapps introduces you to decentralized applications based on the Ethereum blockchain platform. In this book, you'll learn the principles of Dapps development by rolling up your sleeves and actually building a few! Foreword by Thomas Bertani. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the Technology Imagine unbreakably secure applications that handle personal and business transactions without any central agency controlling the process. Decentralized applications, or Dapps, do just this, shifting power to users. The Ethereum blockchain platform provides the tools you need to build Dapps, including an innovative "smart contracts" model and Solidity, a Dapp-aware JavaScript-like programming language. About the Book Building Ethereum Dapps teaches Dapps development on the Ethereum blockchain platform. You'll begin with a mental model of how Dapps operate, and then dive into designing and implementing smart contracts in Ethereum's Solidity language. You'll explore Ethereum smart contract development tools, like Truffle and Web3, and pick up best practices for design and security. Practical exercises throughout give you valuable hands-on experience. What's inside Ethereum's key components Implementing smart contracts in Solidity Communicating with a smart contract in Web3 Developing Dapps with Truffle Best practices for design and security improvement About the Reader For developers with intermediate experience in JavaScript or an OO language. Familiarity with blockchain concepts is helpful. About the Author Roberto Infante is a software development consultant who specializes in finance. He currently works on financial risk management systems and on blockchain technology. Table of Contents PART 1 A first look at decentralized applications Understanding the blockchain The Ethereum platform Deploying your first smart contract PART 2 Programming smart contracts in Solidity Writing more complex smart contracts Generalizing functionality with abstract contracts and interfaces Managing smart contracts with Web3.js PART 3 The Ethereum ecosystem Unit testing contracts with Mocha Improving the development cycle with Truffle Putting it all together: Building a complete voting Dapp PART 4 Making a Dapp production ready Security considerations Conclusions

Download or read book Build Your First Ethereum DApp written by Bruno Škvorc and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we'll walk through the creation of a complete distributed application (DApp) based on the Ethereum platform. We'll be building The Neverending Story , a crowdsourced choose-your-own-adventure story with crowd curation and community censorship. This book is for anyone interested in using the Ethereum platform for development. It's advised that you read The Developer's Guide to Ethereum before reading this book if you are not familiar with blockchain technology.

Download or read book Mastering Ethereum written by Andreas M. Antonopoulos and published by O'Reilly Media. This book was released on 2018-11-13 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethereum represents the gateway to a worldwide, decentralized computing paradigm. This platform enables you to run decentralized applications (DApps) and smart contracts that have no central points of failure or control, integrate with a payment network, and operate on an open blockchain. With this practical guide, Andreas M. Antonopoulos and Gavin Wood provide everything you need to know about building smart contracts and DApps on Ethereum and other virtual-machine blockchains. Discover why IBM, Microsoft, NASDAQ, and hundreds of other organizations are experimenting with Ethereum. This essential guide shows you how to develop the skills necessary to be an innovator in this growing and exciting new industry. Run an Ethereum client, create and transmit basic transactions, and program smart contracts Learn the essentials of public key cryptography, hashes, and digital signatures Understand how "wallets" hold digital keys that control funds and smart contracts Interact with Ethereum clients programmatically using JavaScript libraries and Remote Procedure Call interfaces Learn security best practices, design patterns, and anti-patterns with real-world examples Create tokens that represent assets, shares, votes, or access control rights Build decentralized applications using multiple peer-to-peer (P2P) components

Download or read book Architecture Ethereum DApp with Angular Angular Material and NgRx written by Alex Yevseyevich and published by Alex Yevseyevich. This book was released on 2020-02-29 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a step-by-step guide demonstrating how to build a modern Ethereum blockchain DApp with Ethers.js and IPFS using Angular and NgRx. You'll learn first hand how to harness the power of these exciting technologies by building your own complete application named FleaMarket that runs on Ethereum blockchain and implements the functionality of the Safe Remote Purchase contract.

Download or read book Ethereum For Dummies written by Michael G. Solomon and published by John Wiley & Sons. This book was released on 2019-04-23 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dive into a secure future Professionals look to Ethereum as a blockchain-based platform to develop safe applications and conduct secure transactions. It takes a knowledgeable guiding hand to understand how Ethereum works and what it does — and Ethereum For Dummies provides that guidance. Written by one of the leading voices in the blockchain community and best selling author of Blockchain For Dummies, this book demystifies the workings of Ethereum and shows how it can enhance security, transactions, and investments. As an emerging application of blockchain technology, Ethereum attracts a wide swath of professionals ranging from financial pros who see it as a way to enhance their business, security analysts who want to conduct secure transactions, programmers who build apps that employ the Ethereum blockchain, or investors interested in cashing in on the rise of cryptocurrency. Ethereum For Dummies offers a starting point to all members of this audience as it provides easy-to-understand explanation of the tools and techniques of using Ethereum. Understand the fundamentals of Ethereum Build smart contracts Create decentralized applications Examine public and private chains If you need to get a grip on one of the biggest applications of blockchain technology, this book makes it easier.

Download or read book Ethereum for Web Developers written by Santiago Palladino and published by Apress. This book was released on 2019-09-26 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technology is constantly evolving, and blockchain is taking development to new places, as mobile did a decade ago – and Ethereum is the leading platform for creating this new wave of applications. This book reveals everything you need to create a robust decentralized application (more commonly known as DApp). Unlike other books on the topic, this one focuses on the web application layer, and guides you in creating great experiences on top of the Ethereum blockchain. You’ll review the challenges and differences involved in developing DApps as opposed to traditional web applications. After a brief introduction to blockchain history and Ethereum in particular, you’ll jump directly into building a sample decentralized application, to familiarize yourself with all the moving pieces. This book offers specific chapters on querying and rendering data from the blockchain, reacting to events, interacting with user accounts, sending transactions, managing gas, handling confirmations and reorganizations, and more. You will also find a chapter dedicated to Solidity that will give you the necessary means to understand and even build your own smart contracts. Other important topics covered include building backend servers that act as indexing layers, and managing storage efficiently with solutions like the interplanetary file system, or IPFS. Last but not least, you will find chapters that examine the biggest problems on Ethereum today: onboarding and scalability. These include the state of the art of the available strategies to tackle them, such as meta-transactions, smart accounts, ENS, state channels, sidechains, and more. What You'll Learn Connect to the blockchain from the browser and send transactions from client-sideBuild a web app that provides a read-only interface to a blockchain contract Create a wallet interface for arbitrary fungible tokens, displaying the user’s balance and allowing for simple transfers to other addressesDevelop a web app that stores large blobs of data off-chain, and keeps a reference to it on-chain (e.g. avatars, long text descriptions) Produce a web app that relies on a centralized server for indexing on-chain information to be presented to the user Who This Book Is For Web developers focused on client-side applications, with knowledge of JavaScript and HTML/CSS. You do not need any prior knowledge of Blockchain, Ethereum, or cryptocurrency.

Download or read book Solidity Smart Contracts Build Dapps in Ethereum Blockchain written by Rangel Stoilov and published by Independently Published. This book was released on 2019-02-08 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn Solidity And How To Create Smart Contracts With This Book!For the past couple of years, there hasn't been a bigger breakthrough in the IT world than the one that Blockchain technology has made. The extremely fast growth of the industry, market and the technology itself leads to an enormous shortage of programmers that truly understand the blockchain. Along with the blockchain, smart contracts have emerged and with them - Solidity.The idea of this book is to give you the easiest and best practices in becoming a blockchain developer. We will be focusing on the smart contracts development with Solidity in the Ethereum ecosystem.You will learn to create your first smart contracts in the Ethereum blockchain even if you are a complete beginner and you know nothing about programming or Solidity.I will show you the online IDE Remix to create your first smart contracts and we will go through all the features that Solidity provides us as a programming language.In this book you will learn the following: We'll learn the essentials of the Ethereum blockchain. How to make and protect our wallets as well as mastering Metamask as our main Ethereum wallet in the creation of our smart contracts. We will go through the basic and advanced concepts of the Solidity language. We learn in depth how you can build your own smart contracts and test them out instantly in Remix. I will teach you how to use Metamask as your Ethereum wallet and I will give you security advice that will keep your crypto assets secure. You will have assignments that will help you out understand the material better with actual practice and not only passive consumption. After you finish this course you will fall in love with Solidity, Ethereum ecosystem and the smart contract's creation.

Download or read book Hands On Smart Contract Development with Solidity and Ethereum written by Kevin Solorio and published by O'Reilly Media. This book was released on 2019-11-25 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ready to dive into smart contract development for the blockchain? With this practical guide, experienced engineers and beginners alike will quickly learn the entire process for building smart contracts for Ethereum—the open source blockchain-based distributed computing platform. You’llget up to speed with the fundamentals and quickly move into builder mode. Kevin Solorio, Randall Kanna, and Dave Hoover show you how to create and test your own smart contract, create a frontend for users to interact with, and more. It’s the perfect resource for people who want to break into the smart contract field but don’t know where to start. In four parts, this book helps you: Explore smart contract fundamentals, including the Ethereum protocol, Solidity programming language, and the Ethereum Virtual Machine Dive into smart contract development using Solidity and gain experience with Truffle framework tools for deploying and testing your contracts Use Web3 to connect your smart contracts to an applicationso users can easily interact with the blockchain Examine smart contract security along with free online resources for smart contract security auditing

Download or read book Ethereum Smart Contract Development written by Mayukh Mukhopadhyay and published by Packt Publishing Ltd. This book was released on 2018-02-23 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Become an Ethereum Blockchain developer using a blend of concepts and hands-on implementations Key Features Understand the Ethereum Ecosystem and its differences from its rich cousin Bitcoin Explore the Solidity programming language and smart contract optimizations Get a developer’s perspective of Blockchain-as-a-technology with exposure to common challenges faced while building decentralized applications Book Description Ethereum is a public, blockchain-based distributed computing platform featuring smart contract functionality. This book is your one-stop guide to blockchain and Ethereum smart contract development. We start by introducing you to the basics of blockchain. You'll learn about hash functions, Merkle trees, forking, mining, and much more. Then you'll learn about Ethereum and smart contracts, and we'll cover Ethereum virtual machine (EVM) in detail. Next, you'll get acquainted with DApps and DAOs and see how they work. We'll also delve into the mechanisms of advanced smart contracts, taking a practical approach. You'll also learn how to develop your own cryptocurrency from scratch in order to understand the business behind ICO. Further on, you'll get to know the key concepts of the Solidity programming language, enabling you to build decentralized blockchain-based applications. We'll also look at enterprise use cases, where you'll build a decentralized microblogging site. At the end of this book, we discuss blockchain-as-a-service, the dark web marketplace, and various advanced topics so you can get well versed with the blockchain principles and ecosystem. What you will learn Know how to build your own smart contracts and cryptocurrencies Understand the Solidity language Find out about data types, control structure, functions, inheritance, mathematical operations, and much more See the various types of forks and discover how they are related to Ethereum Get to know the various concepts of web3.js and its APIs so you can build client-side apps Build a DAO from scratch and acquire basic knowledge of DApps on Ethercast Be guided through the project so you can optimize EVM for smart contracts Build your own decentralized applications (DApps) by taking a practical approach Who this book is for If you want to know the ins and outs of the Ethereum network and build your own decentralized applications, then this book is what you need! This book is for anyone who is interested in blockchain and wants to become an Ethereum developer. It’s ideal for existing Ethereum developers who want to develop Ethereum using smart contracts. Basic knowledge of cryptography is expected but is not mandatory.

Download or read book A Developer s Guide to Ethereum written by Bruno Skvorc and published by SitePoint Pty Ltd. This book was released on 2018-08-16 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Blockchain technology has certainly been hyped over the past few years, but when you strip all of that away, what can actually do with it? This book is a collection of articles that provide an introduction to Ethereum, an open source platform that's based based on blockchain. It enables developers to build and deploy decentralized applications that can be relied on to work without fraud, censorship or interference from third parties. We start off by explaining what blockchain is and how it works, and also look at some potential practical applications for blockchain technology. We then move on to looking at the Ethereum platform specifically. Far more than just a cryptocurrency or smart contracts platform, Ethereum is becoming an entire ecosystem for building decentralized applications. This book contains: Blockchain: What It Is, How It Works, Why It's So Popular by Bruno Skvorc What is a Bitcoin Node? Mining versus Validation by Bruno Skvorc How the Lightning Network Helps Blockchains Scale by Bruno Skvorc The Top Nine Uses for Blockchain by Mateja Kendel Introduction to Ethereum: A Cryptocurrency with a Difference by Bruno Skvorc A Deep Dive into Cryptography by Bruno Skvorc 3 Bitcoin Alternatives Compared: Ethereum, Cardano and NEO by David Attard Compiling and Smart Contracts: ABI Explained by Mislav Javor Ethereum Wallets: Send and Receive Ether with MyEtherWallet by Bruno Skvorc Ethereum: How Transaction Costs are Calculated by Bruno Skvorc Proof of Stake vs Proof of Work by Bruno Skvorc Ethereum's Casper: Ghostbusting Proof of Stake Problems by Tonino Jankov Decentralized Storage and Publication with IPFS and Swarm by Tonino Jankov Ethereum Messaging: Explaining Whisper and Status.im by Tonino Jankov Ethereum: Internal Transactions & Token Transfers Explained by Bruno Skvorc BigchainDB: Blockchain and Data Storage by Chris Ward This book is for anyone interested in using the Ethereum platform for development. No prior knowledge of blockchain is assumed.

Download or read book Truffle Quick Start Guide written by Nikhil Bhaskar and published by Packt Publishing Ltd. This book was released on 2018-06-27 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Develop, test, and deploy decentralized applications for Ethereum platform Key Features Build your first Ethereum Dapp with Truffle: the most popular Ethereum development framework Build, compile, and deploy smart contracts in your development environment Embrace Blockchains and utilize it to create new generation of secured and scalable apps Book Description Truffle is a world-class development environment, testing framework and asset pipeline for Ethereum, aiming to make life as an Ethereum developer easier. If you are a web developer wanting to try your hand at developing Dapps with Truffle, then this is the book for you. This book will teach you to write smart contracts and build Dapps with Truffle. You will begin with covering the basics of Truffle, briefly explaining how it integrates Solidity and Web3, in orderto start building a mini decentralized application. Also, you will dive into migration, testing and integrating Truffle with the use of popular JavaScript frameworks. Lastly, you will ship your decentralized application and package it into a product. Moreover, you will go through the best practices in Truffle,so as to increase your proficiency in building Dapps with Truffle. By the end of the book, you will be able to write smart contracts and build decentralized applications with Truffle on Ethereum blockchains. What you will learn Understand the fundamentals of Truffle and Web3 Build a decentralized application with Truffle, while choosing the correct Ethereum client Connect your Dapp to Ethereum clients including Geth, Parity, and Ganache Migrate and test your Dapp with the correct networks such as Ropsten and Rinkeby Package a decentralized application into a user-friendly product by integrating Truffle with JavaScript frameworks such as Angular, React and Vue Explore tools including Ethereum Package Manager, the Registrar and browser wallets, and exploit third-party smart contract libraries. Evaluate the common migration pitfalls and how to mitigate them Who this book is for This book is for web developers who are interested in the new world blockchain. Some basic understanding of JavaScript and web services is required. No prior knowledge of Decentralized applications or blockchain is required.

Download or read book How to Create Your First Ethereum Decentralized Application Using Truffle Ganache and Metamask written by Hemang Subramanian and published by . This book was released on 2021-03-18 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book guides users through a step-by-step process to create a Decentralized Blogging Application using Truffle, Ganache, and Metamask plugins. Our book creates a decentralized blog on top of the ethereum platform, but this can typically be extended to any form of digital content stored on the Ethereum blockchain. For example, the art projects of Crypto Kitties or even NBA stars are digital assets similar to the blogging one, which is the simplest form of storage of digital text on the ethereum blockchain. This illustration is generic to use. This book introduces the following applications in the context of an ethereum decentralized application, namely:Truffle, Ganache, Metamask, Ethereum Dapp, and Node.js web3 libraries. We try to introduce these applications from the point of view of developers who need to understand where to start. This development was conducted using the Windows operating system. A similar development environment can be done using the Linux operating system.We hope that developers who attempt to write it understand how to install Linux, even if it is within a docker kind of environment with the requisite tools and libraries.

Download or read book Ethereum Cookbook written by Manoj P R and published by Packt Publishing Ltd. This book was released on 2018-08-31 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mine Ether, deploy smart contracts, tokens, and ICOs, and manage security vulnerabilities of Ethereum Key Features Build end-to-end decentralized Ethereum apps using Truffle, Web3, and Solidity Explore various solution-based recipes to build smart contracts and foolproof decentralized applications Develop decentralized marketplaces from scratch, build wallets, and manage transactions Book Description Ethereum and Blockchain will change the way software is built for business transactions. Most industries have been looking to leverage these new technologies to gain efficiencies and create new business models and opportunities. The Ethereum Cookbook covers various solutions such as setting up Ethereum, writing smart contracts, and creating tokens, among others. You’ll learn about the security vulnerabilities, along with other protocols of Ethereum. Once you have understood the basics, you’ll move on to exploring various design decisions and tips to make your application scalable and secure. In addition to this, you’ll work with various Ethereum packages such as Truffle, Web3, and Ganache. By the end of this book, you’ll have comprehensively grasped the Ethereum principles and ecosystem. What you will learn Efficiently write smart contracts in Ethereum Build scalable distributed applications and deploy them Use tools and frameworks to develop, deploy, and test your application Use block explorers such as Etherscan to find a specific transaction Create your own tokens, initial coin offerings (ICOs), and games Understand various security flaws in smart contracts in order to avoid them Who this book is for The Ethereum Cookbook is for you if you are a software engineer, Blockchain developer, or research scientist who wants to build smart contracts, develop decentralized applications, and facilitate peer-to-peer transaction. It is assumed that you are familiar with Blockchain concepts and have sound knowledge of JavaScript.

Download or read book Blockchain in Action written by Bina Ramamurthy and published by Manning Publications. This book was released on 2020-11-03 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: There’s a lot more to the blockchain than mining Bitcoin. This secure system for registering and verifying ownership and identity is perfect for supply chain logistics, health records, and other sensitive data management tasks. Blockchain in Action unlocks the full potential of this revolutionary technology, showing you how to build your own decentralized apps for secure applications including digital democracy, private auctions, and electronic record management. Summary There’s a lot more to the blockchain than mining Bitcoin. This secure system for registering and verifying ownership and identity is perfect for supply chain logistics, health records, and other sensitive data management tasks. Blockchain in Action unlocks the full potential of this revolutionary technology, showing you how to build your own decentralized apps for secure applications including digital democracy, private auctions, and electronic record management. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the technology Blockchain is more than just the tech behind Bitcoin—much more! Combining impenetrable security, decentralized transactions, and independently verifiable supply chains, blockchain applications have transformed currency, digital identity, and logistics. Platforms such as Ethereum and Hyperledger make it easy to get started by using familiar programming languages. About the book Blockchain in Action teaches you how to design and build blockchain-based decentralized apps, and is written in a clear, jargon-free style. First, you’ll get an overview of how blockchain works. Next, you’ll code your first smart contract using Ethereum and Solidity, adding a web interface, trust validation, and other features until your app is ready for deployment. The only thing you need to get started is standard hardware and open source software. What's inside Blockchain compared with other distributed systems Development in Solidity Identity, privacy, and security On-chain and off-chain data and operations About the reader For programmers who know JavaScript. About the author Bina Ramamurthy has thirty years of experience teaching distributed systems, data science, peer-to-peer networking, and blockchain. Table of Contents PART 1 - GETTING STARTED WITH BLOCKCHAIN PROGRAMMING 1 Blockchain basics 2 Smart contracts 3 Techniques for trust and integrity 4 From smart contracts to Dapps PART 2 - TECHNIQUES FOR END-TO-END DAPP DEVELOPMENT 5 Security and privacy 6 On-chain and off-chain data 7 Web3 and a channel Dapp 8 Going public with Infura PART 3 - A ROADMAP AND THE ROAD AHEAD 9 Tokenization of assets 10 Testing smart contracts 11 A roadmap to Dapp development 12 Blockchain: The Road ahead

Download or read book Beginning Blockchain written by Bikramaditya Singhal and published by Apress. This book was released on 2018-07-06 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understand the nuts and bolts of Blockchain, its different flavors with simple use cases, and cryptographic fundamentals. You will also learn some design considerations that can help you build custom solutions. Beginning Blockchain is a beginner’s guide to understanding the core concepts of Blockchain from a technical perspective. By learning the design constructs of different types of Blockchain, you will get a better understanding of building the best solution for specific use cases. The book covers the technical aspects of Blockchain technologies, cryptography, cryptocurrencies, and distributed consensus mechanisms. You will learn how these systems work and how to engineer them to design next-gen business solutions. What You'll Learn Get a detailed look at how cryptocurrencies work Understand the core technical components of Blockchain Build a secured Blockchain solution from cryptographic primitives Discover how to use different Blockchain platforms and their suitable use cases Know the current development status, scope, limitations, and future of Blockchain Who This Book Is For Software developers and architects, computer science graduates, entrepreneurs, and anyone wishing to dive deeper into blockchain fundamentals. A basic understanding of computer science, data structure, and algorithms is helpful.

Download or read book Beginning Ethereum and Solidity with React written by Greg Lim and published by Createspace Independent Publishing Platform. This book was released on 2018-06-07 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, we take you on a fun, hands-on and pragmatic journey to learning decentralized application (DApp) development on the Ethereum blockchain using the Solidity programming language. You'll start building your first Ethereum smart contract within minutes. Every section is written in a bite-sized manner and straight to the point as I don't want to waste your time (and most certainly mine) on the content you don't need. In the end, you will have what it takes to develop a real-life decentralized eBay Clone app. In the first chapter, we see how Ethereum works and why do we care about it. In the second chapter, we will create our first working smart contract with Ethereum where we learn how to interact with Ethereum as developers. We will then move on to chapters three and four where we will learn about compiling, deployment and testing of Ethereum apps. All these will prepare us for development of our decentralized eBay clone smart contract and the React user front end in chapter five and six. The goal of this book is to teach you how to build decentralized apps with Ethereum. We won't be talking a lot about trading cryptocurrencies, how to invest in Ethereum or how to trade Ethereum (ether) coins. We will have a good overview of Ethereum and cryptocurrencies but we will not be going into super in-depth academic discussion of them as our focus in this book is to have the practical knowledge of how to work with and build products with Ethereum. Table of Contents: CHAPTER 1: INTRODUCTION TO ETHEREUM CHAPTER 2: INTRODUCTION TO SMART CONTRACTS CHAPTER 3: COMPILING WITH SOLC, UNIT TESTING WITH MOCHA & GANACHE CHAPTER 4: DEPLOYING SMART CONTRACTS TO TEST/MAIN NETWORKS CHAPTER 5: EBAY SMART CONTRACT CHAPTER 6: REACT FRONTEND FOR EBAY SMART CONTRACT