James Bachini

Code

  • Adversarial Simulation Testing For Smart Contract Developers

    Adversarial Simulation Testing For Smart Contract Developers

    I recently read Gene Kranz’s first hand account of the Gemini and Apollo Nasa missions. He talks about the rigorous simulation testing that flight directors had to partake in prior to a mission. Simulation testing plays a crucial role in ensuring the preparedness of astronauts and flight controllers for spaceflight. This process is managed by…

  • Javascript Smart Contracts

    Javascript Smart Contracts

    As an experiment I converted this Vyper token contract to a Javascript/Typescript syntax to see if we could make it easier for web developers to get up to speed with smart contract development. Solidity is the most popular smart contract language and it is already based losely on Javascript but there are plenty of syntax…

  • Vyper Tutorial | Learn Vyper In 24 Hours

    Vyper Tutorial | Learn Vyper In 24 Hours

    Vyper is a pythonesque smart contract language that can be compiled and deployed on Ethereum and other EVM blockchains. 90%+ of blockchain devs use Solidity but there are some big projects such as Curve using Vyper and it’s growing in popularity and tooling compatibility. The best way to get started with Vyper is to head…

  • Using Vyper With Remix

    Using Vyper With Remix

    You can now use Vyper (a smart contract programming language similar to python) with remix to build and deploy contracts on Ethereum and other EVM blockchains. The first step is installing the Vyper plugin at https://remix.ethereum.org/ where you’ll find a list of plugins using the icon in the bottom left. You’ll then get an extra…

  • Sell Me This Pen.sol

    Sell Me This Pen.sol

    What happens when you ask a blockchain developer to sell you a pen? Etch your words permanently on the Ethereum blockchain where they will outlive you & create an everlasting record of your thoughts, contemplations & predictions. This is your chance to leave an eternal mark and express your presence in the digital age while…

  • How To Deploy A Website Or dApp To IPFS | Fleek Tutorial

    How To Deploy A Website Or dApp To IPFS | Fleek Tutorial

    Gm, in this tutorial we are going to be deploying a website to IPFS to create a decentralized frontend. To do this I’ll be using Fleek which has a free tier and which suits our needs. James On YouTube Watch On YouTube: https://youtu.be/https://youtu.be/DmpXbmjnpec |Subscribe We will start by getting our site on Github. We can…

  • TradingView Pine Script Examples | Master Pine Script With 6 Real World Examples

    TradingView Pine Script Examples | Master Pine Script With 6 Real World Examples

    TradingView’s Pine Script coding language has emerged as the leading tool for traders looking to craft custom indicators and strategies with accuracy and ease. In this Pine Script tutorial I’ll provide a practical gateway into the intricacies of this coding language, tailored with useful examples to get you started. Whether you’re a novice coder or…

  • Solidity Proxy Contract Tutorial With Example Code

    Solidity Proxy Contract Tutorial With Example Code

    This Solidity proxy contract tutorial delves into the concept of upgradeable proxy contracts in Solidity, specifically utilizing OpenZeppelin’s proxy contract template. We’ll start with an understanding of how these contracts work, the compromise of immutable decentralization vs upgradeability and then dive into practical code examples. Upgradeable Proxy Contracts A proxy contract is a design pattern…

  • Web3 Session Keys

    Web3 Session Keys

    We are going on a journey to seamlessly integrate session keys into a web3 dApp, striking a balance between autonomy and ease of use that your users are yearning for. The goal is to enable users to authenticate with a digital wallet and store a session key on their device. This session key will provide…

  • Ethers-rs Tutorial | The Rust Web3 Library

    Ethers-rs Tutorial | The Rust Web3 Library

    In this tutorial we will be setting up a Rust script to connect to a smart contract on a blockchain network to display on-chain data using the ethers-rs library. James On YouTube Watch On YouTube: https://youtu.be/FA7WFGtyri8 |Subscribe Let’s start by setting up a new Rust project (you’ll need rust installed on your device and I’ll…

  • ChatGPT Plus vs Free | Is The Paid Version Of ChatGPT Worth It?

    ChatGPT Plus vs Free | Is The Paid Version Of ChatGPT Worth It?

    ChatGPT Plus vs Free [Video] James On YouTube Watch On YouTube: https://youtu.be/U3xXd3vV4iU |Subscribe Why Upgrade To ChatGPT Plus? ChatGPT Plus is the paid version of ChatGPT, it currently costs $20/month + VAT and there are 3 main reasons why the average user would want to upgrade to the premium version: On top of this paid…

  • WAGMI Tutorial | The Web3 React Framework

    WAGMI Tutorial | The Web3 React Framework

    WAGMI is a set of Typescript React hooks for web3 which enables developers to connect to smart contracts on blockchain networks. In this tutorial we will look at how to install and setup a boilerplate in WAGMI and then build a simple read query. WAGMI in 3 Mins [Video] James On YouTube Watch On YouTube:…

  • How I Track Developer Activity For Crypto Projects

    How I Track Developer Activity For Crypto Projects

    In this article I’m going to share how to track developer activity for crypto projects for fundamental analysis. James On YouTube Watch On YouTube: https://youtu.be/DTI7ELSA6CA |Subscribe Understanding the Crypto Development Ecosystem Cryptocurrencies like Bitcoin and Ethereum as well as the majority of blockchain projects are fundamentally software. They are applications that run on a decentralized…

  • How I Built A Smart Money List On Twitter

    How I Built A Smart Money List On Twitter

    X formerly known as Twitter includes two features which allows us to create a list of accounts from people that frontrun narratives and successful trades. tl;dr if you just want to see the final list it is here: https://twitter.com/i/lists/1712044491618545903 James On YouTube Watch On YouTube: https://youtu.be/4qYraarbsYs |Subscribe Step 1. Collecting Project Data My main focus…

  • OpenZeppelin 5 Solidity Common Errors

    OpenZeppelin 5 Solidity Common Errors

    OpenZeppelin have just released version 5 of their Solidity smart contract libraries and there are some breaking changes that are going to cause errors. The two main ones are the Ownable.sol import which allows devs to create onlyOwner functions and the token hooks on ERC20, ERC721 & ERC1155 contracts. Ownable Constructor If you are getting…

  • Hardhat Solidity Tutorial

    Hardhat Solidity Tutorial

    Hardhat is an extensive framework for developing, testing and deploying solidity smart contracts. In this Hardhat Solidity tutorial you will learn how to set it up, how to create hardhat unit test tricks, working with hardhat scripts and finally some Hardhat tips and tricks for Solidity developers. Hardhat Easy Setup Hardhat is built on NodeJS…

  • NEAR BOS | Blockchain Operating System

    NEAR BOS | Blockchain Operating System

    Near BOS is a complete framework designed for creating, testing, deploying and distributing decentralized application frontends. Developers can create Javascript based dApps with the frontend code stored and distributed from a blockchain. It is blockchain agnostic so you can store data on Near and EVM chains. BOS is a collection of components, blockchains & gateways.…

  • Hardhat vs Foundry

    Hardhat vs Foundry

    I started developing solidity with Truffle, then moved to Hardhat, then moved to Foundry, then moved back to Hardhat before eventually settling using both on a regular basis. In this article I’ll talk about the benefits and disadvantages of Hardhat and Foundry so you can make an informed decision about which framework is better for…

  • Calculating The Intrinsic Value Of Bitcoin & Ethereum

    Calculating The Intrinsic Value Of Bitcoin & Ethereum

    Calculating the intrinsic value of Bitcoin, Ethereum and other digital assets is challenging due to its intangible nature. In this analysis I’m going to discuss common methods of calculating intrinsic value and then create a model using a combination of the methods. tl;dr based on the models described below: Methods Of Calculating Intrinsic Value Store…

  • Solidity Tutorial | Gas Paying NFT

    Solidity Tutorial | Gas Paying NFT

    The challenge is to create a NFT contract that charges 1 ETH to mint but then stores the entire amount as collateral in a liquid staking token. As staking rewards come in they get distributed to the holders of the NFTs. At any time a user can burn the NFT to reclaim the 1 ETH.…

  • Web3 PWA Boilerplate | How To Create Next Generation dApps

    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…

  • Chainlink CCIP | Cross-Chain Interoperability Protocol

    Chainlink CCIP | Cross-Chain Interoperability Protocol

    From all the announcements at ETHcc, the release of Chainlink CCIP as a direct competitor to LayerZero for cross-chain communications and bridging technology, is perhaps the most interesting. The inherent security risks associated with bridging technology means that Chainlink are in a good position to leverage their brand and security record to gain traction in…

  • Using Ethereum To Offset Bitcoin’s Carbon Footprint

    Using Ethereum To Offset Bitcoin’s Carbon Footprint

    Never have I sounded more like an Ethereum maxi, but there is a point beyond the provocative title. In this post I’m going to explore the potential for investors to use carbon credit tokens on Ethereum to offset the electrical consumption of BTC mining on their Bitcoin holdings. This novel idea provides the opportunity to…

  • Friend.Tech Trading Bot

    Friend.Tech Trading Bot

    I made a few hundred dollars with this trading bot when Friend.Tech launched. In this tutorial I’m going to show you how to take advantage of system trading web3 opportunities. James On YouTube Watch On YouTube: https://youtu.be/SLh8SN5DRc4 |Subscribe tl;dr Takeaways Trading On Friend.Tech Friend.Tech is a web3 social trading game. You can buy shares in…

  • How To Shuffle A Deck Of Cards In Solidity

    How To Shuffle A Deck Of Cards In Solidity

    In this post I explore how to simulate the shuffling of a deck of cards, addressing the challenges of randomness and predictability in a solidity smart contract environment where every input and output is part of the public record. Whether you’re looking to create an on-chain poker game, a collectible card game, or you’re simply…

  • Card Payments For Crypto With Wert

    Card Payments For Crypto With Wert

    One of the challenges cryptocurrency projects face is the seamless integration of traditional payment systems, such as credit/debit card payments, into their crypto based ecosystems. The issue derives from the potential for fraud because card payments can be reversed long after the transaction has taken place, while crypto transactions are immutable. This is a write…

  • Automate Solidity With MEV

    Automate Solidity With MEV

    There are no cron jobs in Solidity or native to the Ethereum blockchain. To automate Solidity code we can either use an external service/oracle or we can incentivise MEV searchers to complete tasks efficiently on our behalf. This type of Solidity automation is very common and used widely across liquidation systems which require reliable, fast,…

  • Solana SoLang Tutorial | How To Deploy Solidity On Solana

    Solana SoLang Tutorial | How To Deploy Solidity On Solana

    In this SoLang tutorial I’ll show you how to deploy Solidity code on Solana. We will start by setting up a dev environment before looking at some of the nuances in writing SoLang contracts. I’ll end on a few security considerations and a comparison to developing on Solana with SoLang vs Rust. Setting Up A…

  • XRP Legal Case | What It Means For Developers

    XRP Legal Case | What It Means For Developers

    In this article I’m going to be breaking down the document filed by judge Torres yesterday and consider what it means to developers working in the blockchain and web3 space. Highlights From The Ruling The full document is available here:https://www.nysd.uscourts.gov/sites/default/files/2023-07/SEC%20vs%20Ripple%207-13-23.pdf I’ve picked out some highlights Programmatic SalesHaving considered the economic reality of the Programmatic Sales,…

  • Uniswap v4 Hooks

    Uniswap v4 Hooks

    Hooks in Uniswap v4 are external contracts that execute specific actions at certain points during the execution of a liquidity pool. These hooks provide flexibility and customization options for developers to create additional features for liquidity pools. Uniswap v4 hooks can be used to: A 3rd party developer can write a solidity hook contract with…

  • Solidity Error Codes | Not Always What They Seem

    Solidity Error Codes | Not Always What They Seem

    I get a lot of comments from Solidity tutorial videos and in Github issues asking how to resolve common solidity error codes. In this article I’ll go through some of the most frequent solidity issues, what they mean and how to resolve them. UNPREDICTABLE_GAS_LIMIT This is the most common and confusing error in Solidity The…

  • Gnosis Safe | The Most Secure Multisig Wallet For Your Crypto

    Gnosis Safe | The Most Secure Multisig Wallet For Your Crypto

    Gnosis Safe multisig wallets are used by institutions and individuals to hold some of the largest quantities of funds on the Ethereum network. The free to use wallet includes multisignature functionality for enhanced security and control over digital assets. It is developed by Gnosis, a blockchain technology company based out of Switzerland and Germany, known…

  • How Wrapped Tokens Like wETH & wBTC Work

    How Wrapped Tokens Like wETH & wBTC Work

    In this article we will look at how different wrapped tokens work and where the underlying collateral is stored. What Are Wrapped Tokens? Wrapped tokens are generally ERC20 tokens that represents another underlying asset, typically a cryptocurrency or real world asset. The purpose of wrapping a token is to enable its use within the DeFi…

  • 3 Tips For Gas Efficient Solidity Smart Contracts

    3 Tips For Gas Efficient Solidity Smart Contracts

    Here are 3 tips which could be considered the low hanging fruit of gas efficient solidity smart contracts. James On YouTube Watch On YouTube: https://youtu.be/xfNHzqkMWEQ |Subscribe Use Correct Modifiers & Declarations This is the simplest way to get some small wins with gas optimisation. Go through your contract and define anything that shouldn’t change as…

  • Introduction to Flash Loans | Unleashing Capital On Demand

    Introduction to Flash Loans | Unleashing Capital On Demand

    In this tutorial on flash loans we will be creating a Solidity smart contract which takes a flash loan from Uniswap v3. This allows you to borrow huge amounts of capital with the catch that you have to pay it back in the same block or the whole transaction is reverted. James On YouTube Watch…

  • Uniswap Market Maker Bot | Managing Token Liquidity On Uniswap

    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…

  • Ethers vs VIEM | Which Web3 Frontend Library?

    Ethers vs VIEM | Which Web3 Frontend Library?

    Ether.js took over from Web3.js as the number one library for connecting up our dApps to smart contracts running on EVM blockchains. Recently Ethers v6 was released and VIEM is disrupting the space by offering a lightweight Ethereum client library from the authors of WAGMI react hooks. I have always been a big fan of…

  • How To Create A BRC20 Bitcoin Token

    How To Create A BRC20 Bitcoin Token

    In this tutorial we will create our own BRC20 token on the Bitcoin network. James On YouTube Watch On YouTube: https://youtu.be/6eTN2fVd4Pw |Subscribe What are BRC20 Tokens? BRC20 tokens are created using the Bitcoin Ordinals protocol. The Ordinals protocol is a set of rules that govern how inscriptions are created, transferred and managed. Bitcoin and the…

  • Bitcoin Ordinals

    Bitcoin Ordinals

    Bitcoin ordinals are a means of creating NFTs by attaching data such as images, videos, and more to an individual satoshi on the base Bitcoin blockchain. They use an arbitrary but logical ordering system called ordinal theory to give each individual Bitcoin satoshi a unique non-fungible reference. What Are Bitcoin Ordinals? Bitcoin ordinals, also known…

  • Solidity vs Vyper

    Solidity vs Vyper

    Solidity and Vyper are the two most popular programming languages for blockchain developers on Ethereum. Both of these languages have their own strengths and weaknesses which we will go through to help developers decide which is best suited for their project. Solidity Solidity is the most widely used programming language for developing smart contracts on…

  • Sign In With Ethereum Tutorial

    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…

  • Solidity Callback | Solidity Tips & Examples

    Solidity Callback | Solidity Tips & Examples

    A callback function in Solidity allows us to pass a function reference from one contract to another and have it execute as part of an atomic transaction. James On YouTube Watch On YouTube: https://youtu.be/pjm0eOelPXc |Subscribe Let’s first take a look at an example from the Solidity Snippets Github repo. Full code at: https://github.com/jamesbachini/Solidity-Snippets/blob/main/contracts/Callback.sol This code…

  • Strings in Solidity | Solidity Tips & Examples

    Strings in Solidity | Solidity Tips & Examples

    A string in Solidity is a data type used to store text. Working with strings in Solidity can be challenging due to the limitations and efficiency required by the Ethereum virtual machine. This article aims to provide a comprehensive guide on how to use strings in Solidity, covering their properties, limitations, and best practices for…

  • Timestamp in Solidity | Solidity Tips & Examples

    Timestamp in Solidity | Solidity Tips & Examples

    A timestamp is a numerical value that represents a specific moment in time. It’s often used to track when a certain event occurred or when a piece of data was created or modified. The most common way to represent a timestamp is by using the number of seconds that have elapsed since a specific moment…

  • encodeCall in Solidity | Solidity Tips & Examples

    encodeCall in Solidity | Solidity Tips & Examples

    From Solidity version 0.8.11 we can use an interface to define a function to pass to encodeCall parameters. encodeCall is a function that allows you to encode a function call with its parameters into a single byte array. This byte array can then be used to make a low-level call to another contract’s function. Here…

  • Custom Error Handling in Solidity | Solidity Tips & Examples

    Custom Error Handling in Solidity | Solidity Tips & Examples

    Custom error handling enables Solidity developers to efficiently handle reverts and failed transactions including logging parameters. Let’s first take a look at an example from the Solidity Snippets Github repo: Note that the Solidity compiler version must be greater than 0.8.4 to use custom errors. Customer errors are supported by Etherscan and most other block…

  • Solidity Libraries | Solidity Tips & Examples

    Solidity Libraries | Solidity Tips & Examples

    A solidity library is a reusable contract that contains functions that can be called by other contracts. When you import a Solidity library into your contract, you can use the functions provided by the library. How To Import Solidity Libraries In your smart contract, you can import the library by using the import keyword followed…

  • Random Numbers in Solidity | Solidity Tips & Examples

    Random Numbers in Solidity | Solidity Tips & Examples

    Generating a random number in Solidity is not as straightforward as in some other programming languages, because the Ethereum blockchain is deterministic, meaning that multiple execution clients or nodes must come to the same conclusion about the state of the blockchain. For many use cases using the new prevrandao global variable provides “good enough” randomness…

  • Conditional Statements & Loops in Solidity | Solidity Tips & Examples

    Conditional Statements & Loops in Solidity | Solidity Tips & Examples

    Conditional statements & loops in Solidity are fairly intuitive and follow the conventions of other languages such as Javascript. In this article we will go through some examples of each before looking at the relational operators we can use within these statements. if statement The “if” statement is used to execute a block of code…

  • Natspec in Solidity | Solidity Tips & Examples

    Natspec in Solidity | Solidity Tips & Examples

    Natspec comments are important for Solidity developers to understand because sooner or later you will come across a code base that requires you work with them. Proponents will say Natspec makes the code more readable and understandable. While I personally disagree with this and prefer to separate code and documentation, the format is popular and…

  • How The Twitter Algorithm Works

    How The Twitter Algorithm Works

    On the 31st March 2023 Twitter open-sourced large sections of it’s algorithm which ranks content. This provided refreshing insights into how large scale social media applications rank content. In this article I’m going to look at how the algorithm works and how content creators can use this new information to gain more reach and influence.…

  • ERC1155 Token Contract | Solidity Tips & Examples

    ERC1155 Token Contract | Solidity Tips & Examples

    ERC1155 offers a more flexible and efficient way of managing fungible and non-fungible tokens, making it an attractive option for developers who want to create complex digital assets with multiple use cases. In this blog post, we’ll dive into the details of ERC1155 and explore why it’s becoming a preferred choice for Solidity developers looking…

  • ERC721 Token Contract | Solidity Tips & Examples

    ERC721 Token Contract | Solidity Tips & Examples

    The ERC721 Token contract is the original industry standard for NFTs (Non-fungible tokens). In this article we will look at a simple example and talk about some of the best practices around building ERC721 Tokens. James On YouTube Watch On YouTube: https://youtu.be/B64VBGt3tMU |Subscribe Why Use ERC721 Token ERC721 is a standard interface for NFTs on…

  • ERC20 Token Contract | Solidity Tips & Examples

    ERC20 Token Contract | Solidity Tips & Examples

    ERC20 tokens have become the de facto standard for creating tokens on Ethereum and are widely used in many DeFi protocols for things like governance and utility tokens. Why Use ERC20 Token Solidity developers use ERC20 tokens because they are the industry standard for fungible tokens (where every token is equal to another one). The…

  • Merkle Tree in Solidity | Solidity Tips & Examples

    Merkle Tree in Solidity | Solidity Tips & Examples

    Merkle Trees provide an efficient way to verify data in Solidity. This reduces the gas cost for on-chain storage when validating large data sets such as a large list of addresses. James On YouTube Watch On YouTube: https://youtu.be/NTPpyL4pJG0 |Subscribe How Do Merkle Trees Work Merkle trees are a data structure that allow efficient and secure…

  • How To Emit Events in Solidity | Solidity Tips & Examples

    How To Emit Events in Solidity | Solidity Tips & Examples

    A Solidity Event is a way for smart contracts to communicate with the outside world by providing a mechanism for emitting messages that can be observed by external applications. It’s like a signalling message that is broadcast when a certain condition is met within the smart contract. Emitting Events In Solidity Here is a simple…

  • Bulk Send Tokens & ETH Contract | Solidity Tips & Examples

    Bulk Send Tokens & ETH Contract | Solidity Tips & Examples

    Sending payments in bulk can be a tedious and time-consuming process, especially when dealing with a large number of recipients. However, with a Solidity smart contract, bulk payments can be executed in a matter of seconds, providing a more efficient and cost-effective solution for managing bulk transfers. In this article, I will walk you through…

  • Multiple Return Values | Solidity Tips & Examples

    Multiple Return Values | Solidity Tips & Examples

    In Solidity we can multiple return values from a function. This enables us to efficiently move data about within the application flow of a smart contract. In this example we are returning three variables enclosed within brackets. Note that the data types of these variables are defined at the top of the function in the…

  • Modifiers in Solidity | Solidity Tips & Examples

    Modifiers in Solidity | Solidity Tips & Examples

    Modifiers in Solidity are a way to add a certain condition to functions within a smart contract. They allow developers to define a piece of code that can be reused across multiple functions and contracts, making your code more modular and easier to read. A modifier is defined using the modifier keyword, followed by a…

  • Struct in Solidity | Solidity Tips & Examples

    Struct in Solidity | Solidity Tips & Examples

    A struct in Solidity is a data type that allows you to group together multiple variables of different data types into a single unit. This is useful because it gives us a convenient container to package structured data, it enables us to pack variables into memory slots more efficiently and it allows us to get…

  • Ownable Contracts | Solidity Tips & Examples

    Ownable Contracts | Solidity Tips & Examples

    Ownable contracts in Solidity are used to implement access control for certain functions. The idea is that only the contract owner, who is typically the deployer of the contract, can execute these protected functions. To do this we will first import the OpenZeppelin library Inside our contract we can then add the onlyOwner modifier to…

  • Solidity Interface | Solidity Tips & Examples

    Solidity Interface | Solidity Tips & Examples

    A Solidity interface is code that provides a set of function declarations without any implementation details. Interfaces are used to interact with 3rd party contracts or external systems by defining a common set of functions that both parties agree to implement. Interfaces are used to define a contract’s external-facing functions, which is the only part…

  • OpenZeppelin Libraries | Solidity Tips & Examples

    OpenZeppelin Libraries | Solidity Tips & Examples

    OpenZeppelin libraries are popular for building secure smart contracts on top of pre-audited code in Solidity. The framework includes a number of reusable smart contract components, such as token contracts, access control contracts, and math libraries. In this article we will explore the various Libraries available within the OpenZeppelin framework to give you a tool…

  • Arrays in Solidity | Solidity Tips & Examples

    Arrays in Solidity | Solidity Tips & Examples

    Arrays are a fundamental data structure in programming, and Solidity is no exception. In Solidity, there are several types of arrays available, including dynamic arrays, fixed-size arrays, and multi-dimensional arrays. Dynamic Arrays Dynamic arrays are the most common type of array in Solidity. These are arrays whose length can be changed during runtime. To declare…

  • Get Contract Balance | Solidity Tips & Examples

    Get Contract Balance | Solidity Tips & Examples

    To get the contract balance in solidity there are a few different methods depending on if you want the Ether balance or an ERC20 token balance. Contract Balance Eth You can use the address type’s balance property to get the balance of any address, including the contract’s own address. The this value is used to…

  • Mapping in Solidity | Solidity Tips & Examples

    Mapping in Solidity | Solidity Tips & Examples

    This article explores how mapping in Solidity is used to for storing key->value pairs, where the keys are of a specific data type and the values can be of any data type. Mappings are declared using the mapping keyword, followed by the key data type in parentheses and the value data type after the parentheses.…

  • Variables in Solidity | Solidity Tips & Examples

    Variables in Solidity | Solidity Tips & Examples

    Variables in Solidity can be classified into several categories based on their data types and scope. In this article we will explore all the different uses of variables in Solidity and look at some example code. Variables in Solidity Solidity variables are used to store and manipulate data in our smart contracts. They come in…

  • ERC721 vs ERC1155 | Solidity Tips & Examples

    ERC721 vs ERC1155 | Solidity Tips & Examples

    Today we will discuss the differences between ERC721 vs ERC1155 smart contracts and the use cases where each is best suited. These are the two most popular types of smart contracts used for the creation of NFTs (non-fungible tokens). James On YouTube Watch On YouTube: https://youtu.be/B64VBGt3tMU |Subscribe ERC721 Smart Contract ERC721 is the original standard…

  • ERC20 Carbon Credits | Creating A Depleting Token

    ERC20 Carbon Credits | Creating A Depleting Token

    Carbon credits are used to tokenise finances put towards carbon offsetting. On-chain products often have a purchase and burn mechanism where a user must first purchase the token on a DEX and then manually execute a transaction to burn the token. I had the idea to create a automatically depleting token which you just hold…

  • Advanced ChatGPT Prompt Engineering

    Advanced ChatGPT Prompt Engineering

    By now you have probably experimented with ChatGPT and realised the huge potential this “calculator for words” has. In this article I share the results of my research on how to make the most of this powerful tool. Whether you’re using ChatGPT as a personal assistant or in a professional setting, you’ll find some valuable…

  • Remixd Tutorial | How To Take The Solidity IDE To The Next Level

    Remixd Tutorial | How To Take The Solidity IDE To The Next Level

    I’ve gone full circle from Remix > Hardhat > Foundry > Remix I find that I enjoy coding most when I’m experimenting with ideas and proof of concepts within the Remix IDE at https://remix.ethereum.org However for more serious projects I inevitably find myself moving out of creative mode and into testing mode in either Hardhat…

  • LayerZero Example | How To Send Cross-Chain Messages In Solidity

    LayerZero Example | How To Send Cross-Chain Messages In Solidity

    In this article we are going to look at how to send messages or data from one chain to another. In this LayerZero example we will be sending a string from Ethereum’s Goerli Testnet to Optimisms Layer 2 Goerli Testnet. Cross-Chain Tutorial Video James On YouTube Watch On YouTube: https://youtu.be/rKVhQHmljXM |Subscribe How LayerZero Works LayerZero…

  • How To Debug Solidity Smart Contracts

    How To Debug Solidity Smart Contracts

    If you’ve ever received a “gas message” error which makes no sense in Solidity then you’ve probably come across one of it’s greatest flaws. Error reporting and debugging isn’t great for blockchain developers but in this tutorial I’m going to provide some tips, tools and resources to debug Solidity smart contracts. James On YouTube Watch…

  • RAILGUN 2.0 | ZK Privacy Protocol

    RAILGUN 2.0 | ZK Privacy Protocol

    Railgun just announced the launch of version 2.0 this week and in this article we are going to explore the zero knowledge wallet and discuss why privacy protocols are important. In August 2022 Alexey Pertsev was arrested and he has been imprisoned without trial ever since. He was a developer on a ZK mixer called…

  • Timeframe & Budgets For Web3 Development

    Timeframe & Budgets For Web3 Development

    In this article I’m going to provide a timeframe, gantt chart and budget costs for web3 development projects. This assumes a medium sized project for something like a new, innovative DeFi protocol consisting of 5-10 interconnected smart contracts and around 1000 lines of code plus an external audit and dApp frontend. If you are just…

  • Dynamic Evolving NFTs | How To Create Dynamic NFTs & dApps

    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:…

  • POAP vs NFT | A Guide With Examples

    POAP vs NFT | A Guide With Examples

    In this article we will look at what POAPs are and how their technology is built on top of NFT standards. We will also look at how to create simple POAPs and NFTs. In the conclusion I’ve put together some thoughts on why I think POAPs should only be used for fun and not for…

  • Complete Introduction To Web3 Tutorial | Fullstack Web3 Development Tutorial

    Complete Introduction To Web3 Tutorial | Fullstack Web3 Development Tutorial

    This video course provides a complete introduction to Web3 development. The Web3 tutorial starts with a simple Hello World smart contract and React frontend before diving in to create something useful on Ethereum mainnet. Introduction To Web3 Development James On YouTube Watch On YouTube: https://youtu.be/RwuG9HluFQY |Subscribe Hello World Smart Contract James On YouTube Watch On…

  • Solidity Token Factory Contract Walkthrough

    Solidity Token Factory Contract Walkthrough

    A token factory contract is used to deploy tokens from a parent contract within Solidity. In this simple example we will be deploying an ERC20 token from our factory contract. James On YouTube Watch On YouTube: https://youtu.be/MY9SoGPGVoo |Subscribe Full source code below and on Github: https://github.com/jamesbachini/Token-Factory-Tutorial We start with a standard ERC20 token using the…

  • Trading The Merge

    Trading The Merge

    Once or twice a year the crypto markets align to provide exceptional trading volumes and volatility. I believe the Ethereum merge will presents one such opportunity for low time frame system trading. James On YouTube Watch On YouTube: https://youtu.be/3ltpF4UGir4 |Subscribe About The Ethereum Merge The merge is happening in just a few days. This is…

  • The State Of CBDC Central Bank Digital Currency

    The State Of CBDC Central Bank Digital Currency

    Nation states across the world are exploring CBDC’s (central bank digital currency). Many governments including France, Canada, Saudi Arabia & China have pilot schemes already in place. The US dollar is the global reserve currency, it’s used throughout the world as a base asset and more recently as a political weapon in the form of…

  • Aligning Founders, VC’s and Stakeholders Interests In A Smart Contract

    Aligning Founders, VC’s and Stakeholders Interests In A Smart Contract

    The blockchain sector prides itself on openness and transparency. Except that is when it comes to early stage VC deals and token allocations. In this article we are going to look at an experimental solidity smart contract which lays out terms, vesting schedules and milestone bonuses on-chain. Team Allocations and VC Unlock Schedules This is…

  • Dune Analytics Tutorial | How To Create A Dune Analytics Dashboard

    Dune Analytics Tutorial | How To Create A Dune Analytics Dashboard

    In this Dune Analytics Tutorial we will look at how the platform works and get up to speed with creating our own queries, visualisations and dashboards to analyse and present blockchain data. Queries, Visualisations & Dashboards Dune Analytics dashboards are built using a 3 step process. First we make SQL queries to pull data into…

  • Ownable vs Permissionless Smart Contracts

    Ownable vs Permissionless Smart Contracts

    One of the beautiful things about smart contracts is they can be permissionless where the developers relinquish control to the community and all users are treated equally. However less than 20% of the top 50 protocols by TVL on Ethereum are using fully permissionless contracts. In this article we will look at why this is,…

  • Solidity Tutorial | Fixed Rate Staking Contract

    Solidity Tutorial | Fixed Rate Staking Contract

    In this tutorial we will create a fixed rate staking contract that pays out 1 token for every 1 token staked per year. The contract will be built on an OpenZeppelin ERC20 token library with additional functionality for staking. The user will stake their tokens which will lock them in the smart contract at what…

  • 3 Examples Of How To Use Assembly In Solidity

    3 Examples Of How To Use Assembly In Solidity

    Ethereum developers can directly use assembly in Solidity to improve the performance of their code. When OpenSea released the Seaport upgrade it reported the use of assembly reduced gas fees by 35% saving it’s users an estimated $460m per year. Today we are going to go through some simple examples of how and when to…

  • Solidity for Beginners

    Solidity for Beginners

    Solidity is the programming language used to develop smart contracts on Ethereum and other compatible blockchains. In this “Solidity for Beginners” tutorial I will take you from setting up solidity tools to deploying your first contract. James On YouTube Watch On YouTube: https://youtu.be/yM6oRMdMiTM |Subscribe Tools & Setup We will be starting in Remix which is…

  • SBTs 👻 | Soulbound Token Solidity Example

    SBTs 👻 | Soulbound Token Solidity Example

    Soulbound tokens are non-transferable digital assets. The core concept is storing on-chain data directly relating to a specific address. This is nothing new but there is potential for a ERC SBT contract to provide a industry standard for how we manage user data. James On YouTube Watch On YouTube: https://youtu.be/yCHeHI8hUY8 |Subscribe Ethereum gas costs make…

  • Solidity Interface Examples | How To Connect The Lego Bricks Of DeFi

    Solidity Interface Examples | How To Connect The Lego Bricks Of DeFi

    Solidity interfaces allow developers to call external contracts from within their own smart contract. This enables us to build on top of the existing DeFi ecosystem. In this tutorial we will be looking at how solidity interfaces work and going through some example code for common tasks. James On YouTube Watch On YouTube: https://youtu.be/GWZmklp7RTg |Subscribe…

  • Hardhat Plugins & Hacks For Solidity Developers

    Hardhat Plugins & Hacks For Solidity Developers

    Hardhat provides a lot of features out of the box but with the addition of some 3rd party plugins and some additional code snippets we can add custom functionality to streamline our testing and migration processes. Top 3 Hardhat Plugins These plugins add a lot of functionality to make your life as a developer easier…

  • Foundry Tutorial | How To Debug & Deploy Solidity Smart Contracts

    Foundry Tutorial | How To Debug & Deploy Solidity Smart Contracts

    Foundry is a Solidity Framework for building, testing, fuzzing, debugging and deploying Solidity smart contracts. In this Foundry tutorial we will cover the following: Introduction To Foundry [Video] James On YouTube Watch On YouTube: https://youtu.be/VhaP9kYvlOA |Subscribe Smart contracts are most often written in Solidity but tested and deployed using Javascript frameworks such as Truffle or…

  • 5 DeFi Growth Metrics For Better Valuations

    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…

  • How To Generate Artwork For NFT’s With Jang.js

    How To Generate Artwork For NFT’s With Jang.js

    This article explains how to generate artwork for NFT’s like cryptopunks where there are 10,000 profile pictures. Most of the NFT generators you’ll find online are designed for simplicity and ease of use for non-developers. I wanted to create something which was customisable and expandable to allow for more innovative NFT collections. Jang.js “Just Another…

  • Tokenomics Boilerplate | Governance Tokens, Uniswap Buy-Backs and Staking in Solidity

    Tokenomics Boilerplate | Governance Tokens, Uniswap Buy-Backs and Staking in Solidity

    In DeFi a projects success is greatly tied to the effectiveness of the tokenomics. Governance tokens can be distributed to the users to incentivise growth and fees can be used to buy these back on exchange. In this Solidity tutorial we are going to deploy a governance token, a Uniswap v3 liquidity pool, a buy…

  • Introduction To DEX Arbitrage | Intermediate Solidity Tutorial

    Introduction To DEX Arbitrage | Intermediate Solidity Tutorial

    This Solidity tutorial will provide an introduction to DEX arbitrage with real, working, profitable open-source code. Solidity developers have the ability batch multiple swaps together and if they are not profitable revert the entire transaction only paying the transaction fee. The creation of EVM blockchains which have low transaction fees has created a playground for…

  • How To Automate Yield Farming | Harvesting Rewards With A Quick & Dirty Script

    How To Automate Yield Farming | Harvesting Rewards With A Quick & Dirty Script

    Connect wallet, click button, confirm transaction. It gets old pretty quick, especially when you need to do it daily to compound returns. This tutorial takes you through the process of using a block explorer to find functions, calling those functions from a script and then executing to harvest and stake reward tokens. The aim is…

  • How To Make Cross Chain Transfers With Multichain

    How To Make Cross Chain Transfers With Multichain

    I’ve seen Anyswap popping up more and more in on-chain analytics reports as it’s grown to be a six billion dollar protocol by TVL. The platform just rebranded to Multichain and its fast becoming the market leader in cross chain bridges. If you want to transfer USDC from Ethereum to Polygon or Fantom or another…

  • Blockchain Developer Roadmap | A Guide To Learning Blockchain Development

    Blockchain Developer Roadmap | A Guide To Learning Blockchain Development

    This blockchain developer roadmap lays out a framework for learning blockchain development. It should provide a wealth of resources and information for aspiring blockchain developers. Blockchain Developer Roadmap James On YouTube Watch On YouTube: https://youtu.be/h-IcAZX7250 Understanding The Moving Parts There are a number of roles within the blockchain sector and an understanding of what each…

  • Crypto Market Volatility | List Of 100 Altcoin Betas Relative To Bitcoin

    Crypto Market Volatility | List Of 100 Altcoin Betas Relative To Bitcoin

    In this study we are looking at crypto market volatility and how different altcoins markets move relative to Bitcoin. For example if Bitcoin moves up or down 1% Solana will roughly move double that amount for various reasons discussed below. Crypto Market Volatility List FTX Market Beta Volume BTC-PERP 1.01 $4609m ETH-PERP 1.29 $4471m SOL-PERP…