Ethereum : Master Web3js Library

Ethereum : Master Web3js Library

Ethereum : Master Web3js Library

What is Etherum ?

Ethereum is an open source, globally decentralized computing infrastructure that executes programs called smart contracts. It uses a blockchain to synchronize and store the system’s state changes, along with a cryptocurrency called ether to meter and constrain execution resource costs.

The Ethereum platform enables developers to build powerful decentralized applications with built-in economic functions. While providing high availability, auditability, transparency and neutrality, it also reduces or eliminates censorship, and reduces certain counterparty risks.

What is a smart contract ?

The term smart contract has been used over the years to describe a wide variety of different things. In the 1990s, cryptographer Nick Szabo coined the term and defined it as “a set of promises, specified in digital form, including protocols within which the parties perform on the other promises”. Since then, the concept of smart contracts has evolved, especially after the introduction of decentralized blockchain platforms with the invention of Bitcoin in 2009. In the context of Ethereum, the term is actually a bit of a misnomer, given that Ethereum smart contracts are neither smart nor legal contracts, but the term has stuck. In this book, we use the term “smart contract” to refer to immutable computer programs that run deterministically in the context of an Ethereum Virtual Machine as part of the Ethereum network protocol, i.e. on the decentralized Ethereum world computer.

What is a DApp?

A Decentralized Application, or DApp, is an application which is mostly or entirely decentralized.

Consider all the possible aspects of an application that may be decentralized:

Front-end software
Back-end software (logic)
Data storage
Name resolution
Message communications
What is Web3.js ?

web3.js is a collection of libraries which allow you to interact with a local or remote

ethereum node, using a HTTP or IPC connection.

Basic knowledge
This course is start from beginning so every student could joint
What will you learn
You will learn

The big picture
Create web3 object
Local hosted with ganache
Remote hosted with infura
Create new account
Get account balance
Block chain
Block inspection
Subscribe block headers
Subscribe pending transactions
Create contract
Call method
Sub event
Transaction deploy contract
Transaction send ether
Transaction write to smart contract
Blockchain and Ethereum dapp right now are very hot technical trend. Developer with good skill of blockchain and Dapp very easy to get jobs with 6 figures. Are you interesting joining the huge innovation of Dapp ? Joint my course and I will show you.

Understand how to work with Ethereum account
Understand how to work with Ethereum blockchain
Understand how to work with Ethereum smart contract
Understand how to work with Ethereum transaction

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  1. 1 eth for elastos app aerdrop
  2. 0.5 eth for Merkatox excheng aerdrop

How to apply Proof of Stake for Ethereum with Ethermint

How to apply Proof of Stake for Ethereum with Ethermint

Ethermint is designed to be a Proof of Stake implementation of the Ethereum Virtual Machine built on top of Tendermint Core

Ethermint is designed to be a Proof of Stake implementation of the Ethereum Virtual Machine built on top of Tendermint Core

What is it?

ethermint will be an implementation of the EVM that runs on top of tendermint consensus, a Proof of Stake system. This project has as its primary goals:

  • Hard Spoon enablement: This is the ability to take a token from the Ethereum mainnet and "spoon" (shift) the balances over to another network. This feature is intended to make it easy for applications that require more transactions than the Ethereum main chain can provide to move their code over to a compatible chain with much more capacity.
  • Web3 Compatibility: In order enable applications to be moved over to an ethermint chain existing tooling (i.e. web3 compatible clients) need to be able to interact with ethermint.



  • Have a working implementation that can parse and validate the existing ETH Chain and persist it in a Tendermint store
  • Implement Ethereum transactions in the CosmosSDK

Current Work

  • Implement web3 compatible API layer
  • Implement the EVM as a CosmosSDK module
  • Allow the Ethermint EVM to interact with other Cosmos SDK modules

Next Steps

  • Hard spoon enablement: The ability to export state from geth and import token balances into Ethermint
  • Ethermint is a functioning Cosmos SDK application and can be deployed as its own zone
  • Full web3 compatibility will enable existing Ethereum applications to use Ethermint

Building Ethermint

To build, execute the following commands:

# To build the binary and put the resulting binary in ./build
$ make tools verify build

# To build the project and install it in $GOBIN
$ make tools verify install


Integration tests are invoked via:

$ make test

To run CLI tests, execute:

$ make test-cli

Ethereum Mainnet Import

There is an included Ethereum mainnet exported blockchain file in importer/blockchain
that includes blocks up to height 97638. To execute and test a full import of
these blocks using the EVM module, execute:

$ make test-import

You may also provide a custom blockchain export file to test importing more blocks
via the --blockchain flag. See TestImportBlocks for further documentation.

Source Code


The following chat channels and forums are a great spot to ask questions about Ethermint:

Cosmos Riot Chat Channel

Vuethereum: The Vue library Ethereum deserves


An easy Vue.js Component Library for Ethereum Decentralized Applications (Dapps).

Developing blockchain applications for Ethereum (or Dapps) is a roller coaster of emotional ups and downs for developers. The potential decentralization offers is exciting, but the ecosystem is still feeling it’s growing pains as there are still barriers to user adoption and development. As a result, building the frontend for Dapps can be a painful process for developers…until today. The Matryx Team ( has been working on easier ways of creating a Vue.js based frontend for Dapps supporting Ethereum Smart Contracts.

Introducing Vuethereum

Vuethereum is a collection of Vue.js components for interfacing with Ethereum’s Web3. As a result, it combines the power of working with Web3 smart contracts, with the simplicity of developing with Vue.js.

Getting started

Simply install the library via NPM:

npm install vuethereum

Then include it in your project:

// main.js
import Vue from 'vue'
import Vuethereum from ‘vuethereum’
// the rest of your main.js file

What does it include?

At the time of writing, Vuethereum includes four components:

  • vth-blockie: For depicting a string as an Ethereum Blockie.
  • vth-contract: Instantiates a smart contract from a provided ABI and Address.
  • vth-status: A component that provides Web3 details for the current environment.
  • vth-tx: Provides details about a transaction and updates whenever it is mined.

With these tools in place, we can build a complex UI’s that can check if Web3 is available, access the user’s address and network, provide a smart contract to interface with, and finally, show the details from any transaction. Cool!