Advanced Features

Explore advanced capabilities including deployment, account management, and Polkadot-specific features.

Account Management

Generating a Deployment Account

For testnet/mainnet deployments, generate an encrypted account:

yarn generate

This creates an encrypted private key stored in packages/hardhat/.env. You'll be prompted to:

1. Enter a password (used for encryption)
2. Confirm the password

The account details are displayed including:

• Public address
• Mnemonic phrase (write this down!)

Security

• Never commit your .env file
• Store your mnemonic securely offline
• Use different accounts for development and production

Viewing Account Details

yarn account

Shows:

• Address
• Balance on all configured networks
• Network connection status

Importing an Existing Account

Import a private key:

yarn account:import

You'll be prompted for:

• Your private key
• A password to encrypt it

Revealing Private Key

If you need to export your encrypted private key:

yarn account:reveal-pk

Enter your password when prompted.

Deploying to Testnets

1. Prepare Your Account

# Generate account
yarn generate

# Check balance
yarn account

2. Fund Your Account

Get testnet funds from the Polkadot Faucet.

Verify funding:

yarn account

3. Configure Network

Update packages/hardhat/hardhat.config.ts:

const config: HardhatUserConfig = {
  defaultNetwork: "passetHub", // Change to your target network
  // ... rest of config
};

Or specify network in deploy command:

yarn deploy --network passetHub

4. Update Frontend Configuration

Edit packages/nextjs/scaffold.config.ts:

import { passetHub } from "./utils/scaffold-eth/chains";

const scaffoldConfig = {
  targetNetworks: [passetHub], // Match your deployment network
  // ... rest of config
};

5. Deploy

yarn deploy --network passetHub

Enter your password when prompted. Deployment confirmation prints to console.

6. Verify Deployment

Your frontend automatically connects to the deployed contract on the configured network.

Network Configuration

Available Networks

Scaffold-DOT supports these networks out of the box:

Network	Chain ID	RPC URL	Type
localNode	420420420	http://127.0.0.1:8545	Local Dev
Polkadot Hub TestNet	420420417	https://eth-rpc-testnet.polkadot.io	Testnet
Polkadot Hub	420420419	https://eth-rpc.polkadot.io	Mainnet
Kusama Hub	420420418	https://eth-rpc-kusama.polkadot.io	Mainnet

Adding Custom Networks

Define custom networks in both config files:

hardhat.config.ts:

networks: {
  myCustomNetwork: {
    url: "https://rpc.example.com",
    chainId: 12345,
    polkavm: true, // Required for PolkaVM networks
    accounts: [getEncryptedAccount()],
  },
}

scaffold.config.ts:

import { defineChain } from "viem";

export const myCustomNetwork = defineChain({
  id: 12345,
  name: "My Custom Network",
  nativeCurrency: {
    decimals: 18,
    name: "DOT",
    symbol: "DOT",
  },
  rpcUrls: {
    default: { http: ["https://rpc.example.com"] },
  },
  blockExplorers: {
    default: {
      name: "Explorer",
      url: "https://explorer.example.com",
    },
  },
});

Wallet Configuration

Wallet Connection Options

Configure in packages/nextjs/scaffold.config.ts:

const scaffoldConfig = {
  // Traditional wallets (MetaMask, WalletConnect, etc.)
  walletAutoConnect: true,

  // Only use burner wallet on local network
  onlyLocalBurnerWallet: true,

  // Wallet provider (appkit or rainbowkit)
  walletProvider: "appkit",
};

Email & Social Login

Scaffold-DOT supports email and social login via Reown AppKit (default):

Supported Methods:

• 📧 Email (OTP verification)
• 🔵 Google
• 🐦 X (Twitter)
• 💻 GitHub
• 💬 Discord
• 🍎 Apple
• 📘 Facebook
• 🟪 Farcaster

Email and social logins are enabled by default when using AppKit.

Advanced Wallet Providers

For advanced use cases:

• Privy: Embedded wallets with MPC security
• Web3Auth: Advanced authentication flows

Configure provider in packages/nextjs/scaffold.config.ts.

PolkaVM-Specific Features

Gas Configuration

PolkaVM uses a fixed fee model, unlike Ethereum's dynamic gas:

// packages/nextjs/scaffold.config.ts
export const LOCAL_CHAIN_GAS_CONFIG = {
  gasLimit: 1000000n,
  gasPriceMultiplier: 25000,
};

The formula: gasLimit × gasPrice ≥ fixed_fee (≈22 billion wei)

Compiler Configuration

Scaffold-DOT uses resolc to compile Solidity to RISC-V bytecode for PVM:

// packages/hardhat/hardhat.config.ts
const config: HardhatUserConfig = {
  solidity: {
    version: "0.8.28",
    settings: {
      evmVersion: "cancun",
    },
  },
  resolc: {
    compilerSource: "npm", // Uses resolc from npm
  },
};

Contract Hot Reload

Scaffold-DOT automatically updates your frontend when contracts change:

1. Edit contract
2. Run yarn deploy
3. Frontend detects new ABI
4. TypeScript types update
5. UI reflects changes

This is powered by:

• generateTsAbis.ts: Converts ABIs to TypeScript
• deployedContracts.ts: Auto-generated contract definitions
• TypeChain: Generates contract types

External Contracts

Interact with contracts not deployed by Scaffold-DOT:

// packages/nextjs/contracts/externalContracts.ts
import { GenericContractsDeclaration } from "~~/utils/scaffold-eth/contract";

const externalContracts = {
  420420422: { // Paseo Hub
    MyExternalContract: {
      address: "0x...",
      abi: [...],
    },
  },
} as const satisfies GenericContractsDeclaration;

export default externalContracts;

Use with hooks:

const { data } = useScaffoldReadContract({
  contractName: "MyExternalContract",
  functionName: "someFunction",
});

Testing

Writing Tests

// packages/hardhat/test/YourContract.test.ts
import { expect } from "chai";
import { ethers } from "hardhat";
import { YourContract } from "../typechain-types";

describe("YourContract", function () {
  let contract: YourContract;

  beforeEach(async function () {
    const YourContractFactory = await ethers.getContractFactory("YourContract");
    contract = await YourContractFactory.deploy("Hello");
    await contract.waitForDeployment();
  });

  it("Should deploy with correct greeting", async function () {
    expect(await contract.greeting()).to.equal("Hello");
  });

  it("Should update greeting", async function () {
    await contract.setGreeting("Bonjour");
    expect(await contract.greeting()).to.equal("Bonjour");
  });
});

Running Tests

# Run all tests
yarn test

# Run specific test file
yarn hardhat:test test/YourContract.test.ts

# Run with gas reporting
yarn test

Production Deployment

Best Practices

1. Use Separate Accounts: Different accounts for dev/staging/prod
2. Test Thoroughly: Deploy to testnet first
3. Verify Contracts: Use block explorer verification
4. Monitor Deployment: Check transaction status
5. Update Frontend: Ensure frontend points to correct network

Environment Variables

Never commit sensitive data. Use .env files:

# packages/hardhat/.env (gitignored)
ENCRYPTED_PRIVATE_KEY=...
ENCRYPTION_PASSWORD=...

# packages/nextjs/.env.local (gitignored)
NEXT_PUBLIC_WALLET_CONNECT_PROJECT_ID=...

CI/CD Integration

Example GitHub Actions workflow:

name: Deploy to Testnet
on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install dependencies
        run: yarn install
      - name: Deploy contracts
        run: yarn deploy --network passetHub
        env:
          ENCRYPTION_PASSWORD: ${{ secrets.ENCRYPTION_PASSWORD }}

Performance Optimization

Frontend Optimization

// Use React.memo for expensive components
const ExpensiveComponent = React.memo(({ data }) => {
  // ... component logic
});

// Debounce contract reads
import { useDebounce } from "use-debounce";

const [input, setInput] = useState("");
const [debouncedInput] = useDebounce(input, 500);

const { data } = useScaffoldReadContract({
  contractName: "YourContract",
  functionName: "search",
  args: [debouncedInput],
});

Contract Optimization

• Use memory instead of storage when possible
• Minimize state variables
• Batch operations
• Use events for historical data

Troubleshooting

Common Issues

Contract Hot Reload Not Working:

• Ensure yarn deploy completes successfully
• Check packages/nextjs/contracts/deployedContracts.ts updated
• Restart NextJS dev server

Transaction Fails:

• Check gas configuration (PolkaVM fixed fee)
• Verify account has sufficient balance
• Ensure contract function is public or external

Type Errors:

• Run yarn compile to regenerate types
• Check TypeChain types in packages/hardhat/typechain-types/

Next Steps

• Review the API Reference for complete command documentation
• Check Polkadot Smart Contracts Docs
• Join the Scaffold-DOT community for support