full-blockchain-solidity-course-js

This repository holds the code and resources for a video course on blockchain development using JavaScript, originally published on FreeCodeCamp. The course covers how blockchains work, how to write smart contracts in a programming language called Solidity, and how to build web applications that interact with those contracts. The companion video runs over 32 hours and targets complete beginners who want to go from no blockchain knowledge to building real decentralized applications.

A notice at the top of the repository flags that this version is no longer actively maintained. The underlying tooling it relies on, called Hardhat, has changed since the video was recorded, which means parts of the written code no longer match what the video shows. You can still follow along, but you will likely need to debug version and dependency mismatches along the way. The authors point newer learners toward a separate training platform called Cyfrin Updraft, though that platform uses a different toolset called Foundry.

The course is organized into numbered lessons. Early lessons cover the basics: what a blockchain is, how transactions get recorded, and what gas fees mean. Later lessons walk through writing your first contracts in a browser-based editor, deploying them to a test network, building a funding contract that accepts cryptocurrency, creating your own tokens, running lottery-style contracts, and connecting a front-end website to the blockchain. More advanced lessons cover decentralized governance structures and security auditing. Every code sample comes in both JavaScript and TypeScript versions.

The repository references several tools and services used throughout the course: Hardhat for testing and deploying contracts locally, Chainlink for pulling real-world price data into contracts, and the Sepolia test network for practice deployments without using real money. Links to faucets, services that give out free test currency, are included so learners can run transactions immediately.

All code in this repository is for educational use only and has not been formally reviewed for production security. The full README is longer than what was shown.