Ethers.js
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Building Smart Contract Event Filtering Systems for DApps
How events work in web3 Events in Web3 act as logs of significant occurrences within a smart contract. When a specific function is executed, the smart contract can “emit” an event, signalling to external systems that something has happened. These emitted events are stored on the blockchain, but they do not modify the contract’s state.…
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Encrypting Private Keys in .env
It has become very normalised to store Ethereum private keys in plain text within .env files. While this is convenient, it’s a disaster waiting to happen when working in production with wallets that contain real funds. Today, I’ll show you a better way to manage your hot wallet keys using AES encryption. Full code for…
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Creating Your Own Oracle Solidity & NodeJS
In this tutorial I’m going to go through the steps to setting up your own oracle service to bring data on-chain. We are going to be deploying a simple smart contract, then setting up a NodeJS client to fetch the price of Bitcoin, then uploading this to the contract. Full code for this is open…
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Web3 PWA Boilerplate | How To Create Next Generation dApps
One of Web3’s biggest issues is getting around the centralization of app stores and their stringent terms on the commission requirements for digital asset payments and transfers. Progressive Web Apps (PWAs) in my opinion are the best solution as it allows you to install dApps directly on to a mobile device without using the app…
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Uniswap Market Maker Bot | Managing Token Liquidity On Uniswap
In this tutorial I am going to go through how I built a market maker bot to manage liquidity on Uniswap v3 for a token pair. The idea is to create a automated trading bot which buys tokens when price falls below a base line value and sells tokens when price is above the base…
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Sign In With Ethereum Tutorial
To sign in with Ethereum using Metamask we will be using the ERC4361 specification that allows Ethereum accounts to authenticate with off-chain services using a standard message format. This technology offer users a self-custodial alternative to centralized identity providers that generally use email:password credentials. In Web3 applications we can improve user experiences and establish a…
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Dynamic Evolving NFTs | How To Create Dynamic NFTs & dApps
Dynamic NFTs include logic that evolves the underlying data that the NFT contract holds. In this example we will build a picture profile NFT that is upgradeable to an alien 👽 All the source code for this project is available at: https://github.com/jamesbachini/WomenWhoCode Dynamic NFT Smart Contract The Solidity smart contracts will comprise of two tokens:…
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5 DeFi Growth Metrics For Better Valuations
Growth metrics have been used by tech VC’s for years to predict and monitor companies growth patterns. Terms like CAC (Customer acquisition cost) and LTV (Lifetime value) are critical to how we value startups in the traditional space. In DeFi the landscape is different and the metrics that we use are too. However on-chain transparency…