The Web3 Developer Stack

April 12, 2022


A developer stack is a bag of technologies a developer possesses. For example, MEAN (MongoDB, Express.js, AngularJS/Angular, and Node.js) and MERN (MongoDB, Express.js, React, and Node.js) are common web developer stacks. Similarly, today we will learn more about the web3 developer stack and the tech included.

  • Node.js installed on your system.
  • Text editor.
  • Terminal aka Command-Line.
  • Willingness to learn. 

The Developer Stack

If we can imagine web3 as a car then, web3 libraries/dApps are the car's chassis, smart contracts/blockchain are the internal hardware components, wallets which act as the driver’s license, and the node is the fuel that is needed to run the car. Let’s break them down one by one.

  1. Web3 libraries/dApps:
Web3 libraries help us interface with the blockchain easily, make transactions, and interact with smart contracts. Using a web3 library we can develop decentralized applications that reside on the blockchain or interact with it, such as web3.js, ethers.js, and Learn how to work with different web3 libraries in the ‘Web3 SDKs’ section of our guides.

2. Smart contracts:
Smart contracts are pieces of code that reside on the blockchain. They work within the blockchain and are immutable. Smart contracts are written mainly in Solidity. The majority of developers use Remix IDE to write, compile, and deploy the contracts. However, tools like Truffle, Hardhat, and Brownie are handy when a local development environment is needed. Learn about smart contracts in-depth in the Solidity section of our guides.

3. Nodes/Web3 providers:
Nodes or Web3 providers are needed to get the data from the blockchain; nodes run a copy of the blockchain. Nodes are an essential part of the web3 developer stack as without nodes, a web3 library cannot interact with smart contracts. They’re like the gateway to the blockchain realm. QuickNode runs powerful nodes worldwide. Using this global network, you can get lightning-fast access to blockchain data and send faster transactions. 

4. Wallets:
A Wallet address on a blockchain is the identity of an individual and also holds the owner's various cryptocurrencies. Whenever we want to do a write operation on the blockchain, we need to verify the transaction and pay a fee to the network; this is facilitated using the wallet—for example, MetaMask. You can integrate QuickNode with MetaMask by following this guide here. Or instead create your own ETH address/wallet in either JavaScript, Python, Ruby, Go, or PHP

Now, let’s try to understand these techs with an example. We’ll deploy a smart contract that gets  the live price of ETH-USD from Chainlink’s price feed contract.

The wallet

The Chainlink price feed contract, which we’ll use as an interface in our contract, is deployed on the Kovan Testnet. That means we’ll need to deploy our contract on the Kovan Testnet. 

To get started, you will need the MetaMask browser extension to create an ETH wallet and some test ETH, which you can get by going to the Kovan Faucet. You'll need to select Kovan Test Network on your MetaMask wallet and copy the wallet address, go to the faucet page, log in with GitHub or GitLab, paste the wallet address into the text field in the faucet, then click "Send me KETH!".

You can check if you received the test ETH or not by pasting the address into the Kovan Etherscan. If the transaction has been confirmed you should see your balance displayed here.

The contract

Head over to the Ethereum Remix IDE and make a new Solidity file, for example, ethprice.sol.  

Paste the following code into your new Solidity script:

the contract

pragma solidity ^0.6.7;

import "";

contract ethprice {

    AggregatorV3Interface internal priceFeed;

    constructor() public {
        priceFeed = AggregatorV3Interface(0x9326BFA02ADD2366b30bacB125260Af641031331);

    function getLatestPrice() public view returns (int) {
            uint80 roundID, 
            int price,
            uint startedAt,
            uint timeStamp,
            uint80 answeredInRound
        ) = priceFeed.latestRoundData();
        return price;

Explanation of the code above: 

Line 1: Specifying SPDX license type, which is an addition after Solidity ^0.6.8. 

Whenever the source code of a smart contract is made available to the public, these licenses can help resolve/avoid copyright issues. If you do not wish to specify any license type, you can use a special license UNLICENSED or simply skip the whole comment (it won’t result in an error, just a warning).

Line 2: Declaring the Solidity version.

Line 4: Importing the Chainlink contract AggregatorV3Interface.sol for price feed. 

Line 6: Starting our contract named ethprice.

Line 8: Importing the AggregatorV3Interface contract as priceFeed.

Line 10-12: Initializing the constructor interface for AggregatorV3Interface contract with its address, and storing it in priceFeed variable. Doing this we can refer to the AggregatorV3Interface as priceFeed in our contract.

Line 14: Declaring a function getLatestPrice() for type public, which means that it can be accessed outside of the scope of this function and from other contracts. Stating the mutability as view defines that this function will only view and not write or modify any data on the blockchain. The return keyword along with int indicates that the function will return a value in the form of an integer.

Line 16-20: Declaring five variables roundID, price, startedAt, timeStamp, answeredInRound of type integer. These variables are used by the Chainlink contract to store the values returned.

Line 21: Using the function latestRoundData() of Chainlink’s AggregatorV3Interface contract, which we imported as priceFeed. This function will give us the values like price, timestamp of when the price was updated, and store it in variables which we saw in the previous point.

Line 22: Returning the value of price to getLatestPrice() function, so when the getLatestPrice() function is called it’ll return the value of price.

Compile the smart contract by first clicking on the second icon (Solidity icon) on the left menu and then clicking on “Compile ethprice.sol”.

You may see some warnings after compiling the contract. That is because we didn’t use all the variables of method latestRoundData. The function wants all the five variables to be passed into it. We're just asking for the price, which means it'll throw warnings at us, but we shouldn't have anything to worry about. Ensure to copy the ABI using the ABI button and save it; we’ll need it later to interact with the contract.

Now to deploy the contract click on the third icon from the left menu and select injected Web3 from the dropdown under “Environment”. Then click on “Deploy”(make sure to choose Kovan Testnet on MetaMask before deploying the contract). Approve the transaction from MetaMask.

Now that your contract is deployed, you can locate it under the "Deployed Contracts" section, copy the address of the deployed contract by clicking on the copy button and save it; we’ll need it later to interact with the contract.

The Node

We’ll need a Kovan node to interact with our contract, which is deployed on the Kovan blockchain. We’ll sign up for a free trial QuickNode and copy the HTTP PROVIDER URL that we’ll need later to connect to the blockchain.

A screenshot of the Getting Started page on QuickNode with HTTP and WSS links for the Kovan endpoint

The Web3 library

We’ll now write a short JavaScript program using the ethers.js library to interact with our deployed contract.

We’ll install ethers using npm (node package manager), which comes with node.js; learn more about ethers.js in the guide on How to connect to Ethereum network with ethers.js. Open your terminal/cmd, make a new project directory, and then make that directory your current working directory.

the web3 library

mkdir priceDapp
cd priceDapp

Let’s install ethers now:

npm i ethers

The most common issue at this step is an internal failure with `node-gyp`. You can follow node-gyp installation instructions here.

Note: You will need to have your python version match one of the compatible versions listed in the instructions above if you encounter the node-gyp issue. 

Another common issue is a stale cache; clear your npm cache by simply typing the below into your terminal window:

the web3 library

npm cache clean

If you followed the above steps, ethers.js should be installed now.

Create a JavaScript file `price.js`, and copy-paste the following in it:

the web3 library

var ethers = require('ethers');
var provider = new ethers.providers.JsonRpcProvider(url);
var abi = [
		"inputs": [],
		"stateMutability": "nonpayable",
		"type": "constructor"
		"inputs": [],
		"name": "getLatestPrice",
		"outputs": [
				"internalType": "int256",
				"name": "",
				"type": "int256"
		"stateMutability": "view",
		"type": "function"
var contract = new ethers.Contract(address,abi,provider);

contract.getLatestPrice().then((result) =>{
  console.log("$" +result.toNumber()/100000000);

Go ahead and replace `ADD_YOUR_ETHEREUM_NODE_URL` with your QuickNode HTTP provider and `CONTRACT_ADDRESS_FROM_REMIX` with the address of the deployed contract from the above section.

Explanation of the code above:

Line 1: Importing the ethers library.

Line 2: Storing our Quicknode’s URL in the url variable.

Line 3: Instantiating new ethers.providers.JsonRpcProvider instance and storing it in the provider variable.

Line 4: Storing the contract address in the address variable.

Line 5-24: Storing the ABI we got from the previous step in the abi variable.

Line 25: Initializing a contract instance in ethers and connecting it to our deployed contract using the address,abi, and provider.

Line 27: Using the getLatestPrice() from our contract to retrieve ETH’s price in USD and storing it in the result variable.

Line 28: The value from the smart contract is in Big Number, so we’ll need to convert the result to a number and divide it by100000000 to get the value in thousands. Printing the final value to console along with a string $.

Save the file, and run it in your terminal/cmd:

the web3 library

node price

You should now see the latest value of ETH in USD:

Note: The price of ETH/USD can change during your execution; the price in the image above is when this guide was written.


Congratulations :D You’ve taken your first step towards becoming a Web3 developer. We learned what wallets, smart contracts, web3 libraries and nodes are. You also deployed a smart contract and interacted with the contract using ethers.js and QuickNode!

Subscribe to our newsletter for more articles and guides on Ethereum. If you have any feedback, feel free to reach out to us via Twitter. You can always chat with us on our Discord community server, featuring some of the coolest developers you’ll ever meet :)

Related articles 54

How to Send a Transaction On Solana Using JavaScript
Apr 13, 2022

Hello reader! Today is an exhilarating day because we are going on an expedition to the Solana Blockchain. Solana is an up-and-coming blockchain seeking to improve upon the current ecosystem's solutions to the complex problem of providing a secure, scalable, decentralized...

Continue reading
How to do a non-custodial transaction with QuickNode
Apr 12, 2022

Private keys are one of the most sensitive pieces of data when it comes to cryptography and the blockchain. However, there has always been debate/confusion about choosing between custodial wallets (where the wallet provider has custody of the user’s private key) and...

Continue reading
How to connect to Ethereum using .NET (Nethereum)
Apr 12, 2022

Dotnet or .NET is very popular for the development of desktop applications, most Windows desktop applications are built using .NET, and it also contributes largely to web application’s tech stack. In this guide, let’s see how we can connect to Ethereum using .NET and

Continue reading
How to Set Up a Near Project from Scratch
Jan 27, 2022

In this tutorial we will look at how we can setup a basic NEAR project from scratch, installing and configuring dependencies and customizing the project to work well with AssemblyScript.We will first start by initializing our project with a package.json file using...

Continue reading
Como crear y lanzar un ERC-721 (NFT)
Dec 29, 2021

Coleccionables digitales que son compatibles con ERC-721 se han vuelto muy populares desde el lanzamiento de Cryptokitties y han ganado adopción masiva en los últimos meses. Esta guía cubrirá la parte de creación y lanzamiento...

Continue reading
How to connect to Ethereum network using Java / Web3j
Apr 12, 2022

We can say that Java is one of the most versatile languages out there, and it continues to be relevant in today's time. Java is so popular because of its massive user base and use cases. In this guide/tutorial, we'll learn how to connect to the Ethereum Blockchain network...

Continue reading
How to integrate IPFS with Ethereum
Apr 12, 2022

It can be costly to store massive files on a blockchain mainnet, and this is where decentralized file storing systems like IPFS can come in handy. Sometimes, NFTs use IPFS as well. In this guide, we’ll cover how we can integrate IPFS with...

Continue reading
How to Connect to the Ethereum Network using Ruby
Jun 13, 2022

The Ruby programming language has a huge fanbase. Ruby was developed by its creator with an intention to invent a language developers can enjoy learning and using. Ruby has been largely accepted by developers all around the world since its launch, in fact, the biggest...

Continue reading
How to connect to Ethereum network with ethers.js
Apr 12, 2022

When someone thinks of developing a dApp the first tool that comes to their mind is web3.js which is pretty common because of its popularity in the community and wide use cases, dApp development has been consistently growing and there are a lot of developers who want to...

Continue reading
How to Mint an NFT on Solana
Apr 12, 2022

Updated at: April 10, 2022Welcome to another QuickNode guide on Solana - the up-and-coming blockchain that seeks to solve the scalability issues of Ethereum. We will be walking through step-by-step how to create an NFT on Solana. NFT, short for Non Fungible Token,...

Continue reading
How to deploy a smart contract with Brownie
Apr 12, 2022

Python is one of the most versatile programming languages; from researchers running their test models to developers using it in heavy production environments, it has use cases in every possible technical field. In today's guide, we will learn about Brownie, a Python-based...

Continue reading
How to Get All Tokens Held by a Wallet in Solana
Jun 24, 2022

Hello readers! To kick off Solana Summer and the current whitelist meta, we thought it would be helpful to dig into all of the token accounts you and your users have using the getParsedProgramAccounts method. This tool is convenient for querying different...

Continue reading
Introduction to Scaffold-ETH 🏗
Dec 29, 2021

Developing applications involves juggling several moving pieces like front-ends, back-ends, and databases. But developing a decentralized application on a blockchain adds a few more elements like smart contracts and nodes that allow you to connect to the...

Continue reading
Como crear un NFT en SOLANA
Dec 29, 2021

¡Hola querido lector! Bienvenidos a una nueva guía de Solana.Solana es una blockchain que promete mucho a la hora de intentar resolver los problemas de escalabilidad que podemos apreciar en otras blockchains, como Ethereum por...

Continue reading
How to Get Transaction Logs on Solana
Jun 28, 2022

Ever need to pull all the transactions associated with a Wallet? Want to see all of the mint transactions associated with a Candy Machine? Or maybe see transaction history of an NFT? Solana's getSignaturesForAddress method is a versatile tool that makes...

Continue reading
How to Send an EIP-1559 Transaction
Apr 12, 2022

While Ethereum has been trying to scale, it has encountered some gas price issues. Many layer 2 solutions and sidechains sprang into existence to solve this problem, but Ethereum is the main chain, and at some point, it has to be improved. EIP-1559 was introduced to...

Continue reading
How to Create an Address in Solana using JavaScript
Apr 12, 2022

Hello reader! Welcome to QuickNode's first Solana guide. Solana is an up-and-coming blockchain that seeks to solve the scalability issues that Ethereum has been handling. You will walk through step-by-step how to create a Solana address using the @solana/web3.js...

Continue reading
How to create your own DAO with Aragon
Apr 12, 2022

Blockchain provides us with the power of decentralization. Decentralization means the transfer of power to users/members rather than having a single centralized authority governing everything; it enables various use cases in finance, governance, voting, fundraising, etc....

Continue reading
How to Connect to Terra with JavaScript using Terra.js
Apr 12, 2022

Stablecoins have been bridging the gap between traditional currencies and blockchains. Stablecoins offer stable price tokens pegged by a reserve asset which is often a fiat current like USD, EUR, GBP. The Terra protocol provides a framework to work with stablecoins. This...

Continue reading
How to connect to Ethereum network using Go
Apr 12, 2022

Go helps you make faster scalable backends and this guide will show you how to connect your backend to Ethereum (and make it even faster, more reliable, and globally accessible, all thanks to QuickNode’s global infrastructure). What is...

Continue reading
How To Fork Ethereum Mainnet with Hardhat
Apr 12, 2022

Forking the chain at an older block of the blockchain is helpful if you want to simulate the blockchain’s state at that block; Hardhat has this functionality built in. In this guide, let’s go through the process of forking the Ethereum Mainnet at an older...

Continue reading
How to connect to Ethereum using PHP
Apr 12, 2022

PHP is a very popular choice among developers and has a vast community due to its long presence in web development. In this guide, we’ll cover how to connect to Ethereum with PHP using the web3.php...

Continue reading
How to use Subspace with QuickNode
Apr 12, 2022

In this guide, we'll understand a bit about reactive development and how to use Subspace with QuickNode.JavaScript is the programming language behind most of the internet apps and websites. JavaScript today has become one of the most used programming languages,...

Continue reading
How to Connect Your Dapp With MetaMask Using Ethers.js
Dec 29, 2021

In our dApp, we will have a simple react user interface that has a material button asking the user to connect to MetaMask. And if they do not have an account, they can create one or log in to their account. They will then view their wallet balance and address displayed on...

Continue reading
How to generate a new Ethereum address in Go
Dec 29, 2021

Golang is very popular among backend developers for building infrastructures and microservices. Go is a procedural programming language. Developed in 2007 by Robert Griesemer, Rob Pike, and Ken Thompson at Google, then launched in 2009 as...

Continue reading
How to generate a new Ethereum address in Python
Dec 29, 2021

Python is one of the most versatile programming languages out there with an abundance of use cases; We can build many applications with Python from client-side to back end. In this guide, we will cover creating an Ethereum address in Python using the

Continue reading
How to Lazy Mint an NFT on Rarible with Rarepress
Apr 12, 2022

NFTs are great for creators to monetize their artwork and for people to get ownership of an item. But since gas prices are usually high given the highly in-demand space on Ethereum, minting an NFT or an NFT collection can become costly for a creator. Lazy minting solves...

Continue reading