is everything you need to get started building decentralized applications powered by smart contracts

quickstart

git clone https://github.com/austintgriffith/scaffold-eth.git your-next-dapp
cd your-next-dapp

yarn install

you might get node-gyp errors, ignore them and run:

yarn start

in a second terminal window:

yarn chain

in a third terminal window:

yarn deploy

🔏 Edit your smart contract YourContract.sol in packages/hardhat/contracts

📝 Edit your frontend App.jsx in packages/react-app/src

📱 Open http://localhost:3000 to see the app

📚 Keep solidity by example handy and check out the Solidity globals and units

With everything up your dev environment starts looking something like this:

React dev server, HardHat blockchain, deploy terminal, code IDE, and frontend browser.

🔁 You can yarn run deploy any time and get a fresh new contract in the frontend:

💵. Each browser has an account in the top right and you can use the faucet (bottom left) to get ⛽️ testnet eth for gas:

🔨 Once you have funds, you can call setPurpose on your contract and "write" to the purpose storage:

Look for the HardHat console.log() output in the yarn run chain terminal:

👨‍🏫 Maybe start super simple and add a counter uint8 public count = 1;

⬇️ Then a function dec() public {} that does a count = count - 1;

🔬 What happens with you subtract 1 from 0? Try it out in the app to see what happens!

🚽 UNDERFLOW!

🧫 You can iterate and learn as you go. Test your assumptions!

💵 Send testnet ETH between browsers or even on an instantwallet.io selecting localhost:

🔐 Global variables like msg.sender and msg.value are cryptographically backed and can be used to make rules

📝 Keep this cheat sheet handy

⏳ Maybe we could use block.timestamp or block.number to track time in our contract

🔏 Or maybe keep track of an address public owner; then make a rule like require( msg.sender == owner ); for an important function

🧾 Maybe create a smart contract that keeps track of a mapping ( address => uint256 ) public balance;

🏦 It could be like a decentralized bank that you function deposit() public payable {} and withdraw()

📟 Events are really handy for signaling to the frontend. Read more about events here.

📲 Spend some time in App.jsx in packages/react-app/src and learn about the 🛰 Providers

⚠️ Big numbers are stored as objects: formatEther and parseEther (ethers.js) will help with WEI->ETH and ETH->WEI.

🧳 The single page (searchable) ethers.js docs are pretty great too.

🐜 The UI framework Ant Design has a bunch of great components.

📃 Check the console log for your app to see some extra output from hooks like useContractReader and useEventListener.

🏗 You'll notice the <Contract /> component that displays the dynamic form as scaffolding for interacting with your contract.

🔲 Try making a <Button/> that calls writeContracts.YourContract.setPurpose("👋 Hello World") to explore how your UI might work...

💬 Wrap the call to writeContracts with a tx() helper that uses BlockNative's Notify.js.

🧬 Next learn about structs in Solidity.

🗳 Maybe an make an array YourStructName[] public proposals; that could call be voted on with function vote() public {}

🔭 Your dev environment is perfect for testing assumptions and learning by prototyping.

📝 Next learn about the fallback function

💸 Maybe add a receive() external payable {} so your contract will accept ETH?

🚁 OH! Programming decentralized money! 😎 So rad!

🛰 Ready to deploy to a testnet? Change the defaultNetwork in packages/hardhat/hardhat.config.js

🔐 Generate a deploy account with yarn generate and view it with yarn account

🔑 Create wallet links to your app with yarn wallet and yarn fundedwallet

👩‍🎓 You can "graduate" from 🏗 scaffold-eth and start using 👷 HardHat and 📦 create-eth-app "standalone"

( You will probably want to take some of the 🔗 hooks, 🎛 components with you from 🏗 scaffold-eth so we started 🖇 eth-hooks )

🚀 Good luck!

Learn how to quickly iterate on a smart contract app using the \<Contract /> component.

Join the telegram support chat 💬 to ask questions and find others building with 🏗 scaffold-eth!

🎥. Watch the long form 🏗 scaffold-eth introduction on youtube for the EEA.

Learn the basics of 🏗 scaffold-eth and building on Ethereum. 👷‍♂️ HardHat, 📦 create-eth-app, 🔥 hot reloading smart contracts, 🛰 providers, 🔗 hooks, 🎛 components, and building a decentralized application. 🎥 Guided Tutorial

Learn about tokens. [coming soon] What is a token? Why is it cool? How can I deploy one? Exotic mechanisms? (todo)

Learn the basics of Automated Market Makers like 🦄 Uniswap. Learn how 💰Reserves affect the 📉 price, ⚖️ trading, and 💦 slippage from low liqudity.

🏃‍♀️ SpeedRun 📹

Build a simple IPFS application in 🏗 scaffold-eth to learn more about distributed file storage and content addressing. 🎥 Live Tutorial

Learn about to provide your users with better UX by abstracting away gas fees and blockchain mechanics. (todo)

Learn how to deploy your smart contract to a production blockchain. Then deploy your applicaton to Surge, S3, and IPFS. Finally, register an ENS and point it at the decentralized content! 🎥 Live Tutorial

📡 Using The Graph with 🏗 scaffold-eth

built with 🏗 scaffold-eth:

Paintings come to life as you "ink" new creations and trade them on Ethereum. A deep dive into 🖼 NFTs, 🐳 OpenSea, 🖍 react-canvas-draw, 🎨 react-color, and 🛬 onboarding user experience.

🏃‍♂️ SpeedRun 📹 (TODO)

💾 Source Code

An instant wallet running on xDAI insired by xdai.io.

💾 Source Code

Poll your holders! Build an example emoji voting system with 🏗 scaffold-eth. 🔏 Cryptographically signed votes but tracked off-chain with 📡 Zapier and 📑 Google Sheets.

🏃‍♂️ SpeedRun 📹

💾 Source Code

Exchange Reddit MOONs for ETH or DAI through xDAI. Learn about different 🛰 providers and how 🌉 bridges can connect different chains with different security models.

🏃‍♂️ SpeedRun 📹

💾 Source Code

Remember someone permanently on the blockchain. Write an obituary and upload a photo of a person and their memory will be encoded on the blockchain, forever.

^^^ ⛏ PR your 🏗 scaffold-eth project in above!!! ^^^

🧫 Building on Ethereum in 2020 (research)

⏱ Original Quickstart with TODO List:

First, you'll need NodeJS>=10 plus Yarn and Git installed.

💾 install:

git clone https://github.com/austintgriffith/scaffold-eth.git rad-new-dapp
cd rad-new-dapp
git checkout quickstart
yarn install

⌚️ This will take some time. How about a quick tour of the file structure with your favorite code editor?

💡 Sometimes the install throws errors like "node-gyp", try the next step even if you see problems.
(You can also download the Apple command line tools to fix the warning.)

🎛 frontend

yarn start

📝 Edit your frontend App.jsx in packages/react-app/src and open http://localhost:3000

⛓ blockchain

yarn run chain

Note: You'll need to run this command in a new terminal window

🛠 Use this eth.build to double-check your local chain and account balances

⚙️ Compile your contracts:

yarn run compile

🚢 Deploy your contracts to the frontend:

yarn run deploy

🔍 Watch for changes then compile, deploy, and hot reload the frontend:

yarn run watch

🔥 Your dapp hot reloads as you build your smart contracts and frontend together 🔥

📝 Edit your smart contract SmartContractWallet.sol in packages/hardhat/contracts

🤡 There is a spelling error in packages/hardhat/contracts/SmartContractWallet.sol!

🤔 Can you fix it and deploy the contract locally?

☢️ Warning: It is very important that you find SmartContractWallet.sol in packages/hardhat/contracts because there are other contract folders and it can get confusing.

🔬Test your contracts by editing myTest.js in packages/hardhat/contracts:

yarn run test

🗝 List your local accounts:

yarn run accounts

💰 Check account balance:

yarn run balance **YOUR-ADDRESS**

💸 Send ETH:

yarn run send --from 0 --amount 0.5 --to **YOUR-ADDRESS**

🔧 Configure 👷HardHat by editing hardhat.config.js in packages/hardhat

✨ The HardHat network provides stack traces and console.log debugging for our contracts ✨

🏃‍♂️ Speedrun (🎥 7 min):

🔬 Smart Contract Sandbox:

💾 install:

git clone https://github.com/austintgriffith/scaffold-eth.git smart-contract-sandbox
cd smart-contract-sandbox
yarn install

⚙️ start

#run in original terminal window:
yarn start
#run in terminal window 2:
yarn run chain
#run in terminal window 3:
yarn run deploy

🔏 Edit or rename your smart contract YourContract.sol in packages/hardhat/contracts

📝 Edit your frontend App.jsx in packages/react-app/src

📱 Open http://localhost:3000 to see the app

☢️ Make sure are running your local chain yarn run chain and your contract is deployed with yarn run deploy

🔥 Try yarn run watch and as you change your Solidity, your frontend \<Contract/> will hot reload to give you access to new variables and functions:

📽 Video Guide

📚 RTFM: Check out solidity by example and check out the Solidity globals and units

🚀 Good luck, and go get 'em!

🔏 Web3 Providers:

The frontend has three different providers that provide different levels of access to different chains:

mainnetProvider: (read only) Infura connection to main Ethereum network (and contracts already deployed like DAI or Uniswap).

localProvider: local HardHat accounts, used to read from your contracts (.env file points you at testnet or mainnet)

injectedProvider: your personal MetaMask, WalletConnect via Argent, or other injected wallet (generates burner-provider on page load)

🐜 Ant.design is the UI library with components like the grids, menus, dates, times, buttons, etc.

⛑ Helpers:

Transactor: The transactor returns a tx() function to make running and tracking transactions as simple and standardized as possible. We will bring in BlockNative's Notify library to track our testnet and mainnet transactions.

const tx = Transactor(props.injectedProvider, props.gasPrice);

Then you can use the tx() function to send funds and write to your smart contracts:

tx({
  to: readContracts[contractName].address,
  value: parseEther("0.001"),
});

tx(writeContracts["SmartContractWallet"].updateOwner(newOwner));

☢️ Warning: You will need to update the configuration for react-app/src/helpers/Transactor.js to use your BlockNative dappId

🖇 Hooks:

Commonly used Ethereum hooks located in packages/react-app/src/:

usePoller(fn, delay): runs a function on app load and then on a custom interval

usePoller(() => {
  //do something cool at start and then every three seconds
}, 3000);

useBalance(address, provider, [pollTime]): poll for the balance of an address from a provider

const localBalance = useBalance(address, localProvider);

useBlockNumber(provider,[pollTime]): get current block number from a provider

const blockNumber = useBlockNumber(props.provider);

useGasPrice([speed]): gets current "fast" price from ethgasstation

const gasPrice = useGasPrice();

useExchangePrice(mainnetProvider, [pollTime]): gets current price of Ethereum on the Uniswap exchange

const price = useExchangePrice(mainnetProvider);

useContractLoader(provider): loads your smart contract interface

const readContracts = useContractLoader(localProvider);
const writeContracts = useContractLoader(injectedProvider);

useContractReader(contracts, contractName, variableName, [pollTime]): reads a variable from your contract and keeps it in the state

const title = useContractReader(props.readContracts, contractName, "title");
const owner = useContractReader(props.readContracts, contractName, "owner");

useEventListener(contracts, contractName, eventName, [provider], [startBlock]): listens for events from a smart contract and keeps them in the state

const ownerUpdates = useEventListener(
  readContracts,
  contractName,
  "UpdateOwner",
  props.localProvider,
  1
);

📦 Components:

Your commonly used React Ethereum components located in packages/react-app/src/:

📬 <Address />: A simple display for an Ethereum address that uses a Blockie, lets you copy, and links to Etherescan.

  <Address value={address} />
  <Address value={address} size="short" />
  <Address value={address} size="long" blockexplorer="https://blockscout.com/poa/xdai/address/"/>
  <Address value={address} ensProvider={mainnetProvider}/>

🖋 <AddressInput />: An input box you control with useState for an Ethereum address that uses a Blockie and ENS lookup/display.

  const [ address, setAddress ] = useState("")
  <AddressInput
    value={address}
    ensProvider={props.ensProvider}
    onChange={(address)=>{
      setAddress(address)
    }}
  />

TODO GIF

💵 <Balance />: Displays the balance of an address in either dollars or decimal.

<Balance
  address={address}
  provider={injectedProvider}
  dollarMultiplier={price}
/>

👤 <Account />: Allows your users to start with an Ethereum address on page load but upgrade to a more secure, injected provider, using Web3Modal. It will track your address and localProvider in your app's state:

const [address, setAddress] = useState();
const [injectedProvider, setInjectedProvider] = useState();
const price = useExchangePrice(mainnetProvider);

<Account
  address={address}
  setAddress={setAddress}
  localProvider={localProvider}
  injectedProvider={injectedProvider}
  setInjectedProvider={setInjectedProvider}
  dollarMultiplier={price}
/>

💡 Notice: the <Account /> component will call setAddress and setInjectedProvider for you.

☢️ Warning: You will need to update the configuration for Web3Modal to use your Infura Id

📡 <Provider />: You can choose to display the provider connection status to your users with:

<Provider name={"mainnet"} provider={mainnetProvider} />
<Provider name={"local"} provider={localProvider} />
<Provider name={"injected"} provider={injectedProvider} />

💡 Notice: you will need to check the network id of your injectedProvider compared to your localProvider or mainnetProvider and alert your users if they are on the wrong network!

📄 Smart Contract Wallet:

📝 Edit your smart contract SmartContractWallet.sol in packages/hardhat/contracts

📝 Then edit the SmartContractWallet.js React component in packages/react-app/src

▶️ Run yarn run compile and yarn run deploy or just yarn run watch

🛠 Run this eth.build with your contract address to ask it who its owner is.

📚 OpenZeppelin Contracts -- TODO

You can import any of the OpenZeppelin contracts:

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

🛰 The Graph -- TODO

⛽️ GSN -- TODO

📤 Save to your Git

Create a new repo with the same name as this project and then:

git remote add origin https://github.com/**YOUR_GITHUB_USERNAME**/**YOUR_COOL_PROJECT_NAME**.git
git push -u origin master

🛳 Ship it!

You can deploy your static site and your dapp can go live:

yarn run build
# ship it!
yarn run surge
OR
yarn run s3
OR
yarn run ipfs