Web3 Frontend Skill

Master Web3 frontend development with wallet integration, modern libraries (viem/wagmi), and production dApp patterns.

Quick Start

# Invoke this skill for Web3 frontend development
Skill("web3-frontend", topic="wallet", framework="react")

Topics Covered

1. Wallet Integration

Connect users to Web3:

• RainbowKit: Beautiful wallet modal
• WalletConnect: Mobile support
• Account Abstraction: ERC-4337
• Multi-chain: Network switching

2. Transaction Management

Handle blockchain interactions:

• Write Operations: Contract writes
• State Tracking: Pending, confirmed
• Gas Estimation: Fee display
• Error Handling: User-friendly messages

3. Signing & Auth

Verify user identity:

• EIP-712: Typed data signing
• SIWE: Sign-In with Ethereum
• Permit: Gasless approvals
• Message Signing: Personal sign

4. React Hooks

Modern patterns with wagmi:

• useAccount: Connection state
• useWriteContract: Transactions
• useReadContract: Data fetching
• useWaitForTransactionReceipt: Confirmations

Code Examples

Connect Wallet

'use client';

import { ConnectButton } from '@rainbow-me/rainbowkit';
import { useAccount } from 'wagmi';

export function WalletConnect() {
  const { address, isConnected } = useAccount();

  return (
    <div>
      <ConnectButton />
      {isConnected && <p>Connected: {address}</p>}
    </div>
  );
}

Write Contract

import { useWriteContract, useWaitForTransactionReceipt } from 'wagmi';
import { parseEther } from 'viem';

export function MintButton() {
  const { writeContract, data: hash, isPending } = useWriteContract();
  const { isLoading, isSuccess } = useWaitForTransactionReceipt({ hash });

  const mint = () => {
    writeContract({
      address: '0x...',
      abi: [...],
      functionName: 'mint',
      args: [1n],
      value: parseEther('0.08'),
    });
  };

  return (
    <button onClick={mint} disabled={isPending || isLoading}>
      {isPending ? 'Confirm in wallet...' :
       isLoading ? 'Minting...' :
       isSuccess ? 'Minted!' : 'Mint NFT'}
    </button>
  );
}

Sign Typed Data (EIP-712)

import { useSignTypedData } from 'wagmi';

const DOMAIN = {
  name: 'My App',
  version: '1',
  chainId: 1,
  verifyingContract: '0x...',
};

export function useSignOrder() {
  const { signTypedDataAsync } = useSignTypedData();

  const sign = async (order: Order) => {
    return await signTypedDataAsync({
      domain: DOMAIN,
      types: { Order: [...] },
      primaryType: 'Order',
      message: order,
    });
  };

  return { sign };
}

Error Handling

export function parseError(error: unknown): string {
  const msg = error instanceof Error ? error.message : String(error);

  if (msg.includes('user rejected')) return 'Transaction cancelled';
  if (msg.includes('insufficient funds')) return 'Insufficient balance';
  if (msg.includes('execution reverted')) {
    const reason = msg.match(/reason="([^"]+)"/)?.[1];
    return reason || 'Transaction would fail';
  }

  return 'Transaction failed';
}

Package Setup

npm install wagmi viem @rainbow-me/rainbowkit @tanstack/react-query

// providers/Web3.tsx
import { WagmiProvider } from 'wagmi';
import { RainbowKitProvider } from '@rainbow-me/rainbowkit';
import { QueryClientProvider, QueryClient } from '@tanstack/react-query';
import { config } from './config';

const queryClient = new QueryClient();

export function Web3Provider({ children }) {
  return (
    <WagmiProvider config={config}>
      <QueryClientProvider client={queryClient}>
        <RainbowKitProvider>{children}</RainbowKitProvider>
      </QueryClientProvider>
    </WagmiProvider>
  );
}

Common Patterns

Pattern	Use Case	Hook
Connect wallet	User auth	useAccount
Read data	Display balances	useReadContract
Write tx	Mint, transfer	useWriteContract
Wait for tx	Confirm state	useWaitForTransactionReceipt
Sign message	Auth, permit	useSignMessage

Common Pitfalls

Pitfall	Issue	Solution
Hydration error	SSR mismatch	Use dynamic with ssr: false
BigInt serialization	JSON.stringify	Custom serializer
Stale data	Cache issues	Use refetchInterval

Troubleshooting

"Wallet not connecting"

// Ensure client-side only
import dynamic from 'next/dynamic';

const ConnectButton = dynamic(
  () => import('./ConnectButton'),
  { ssr: false }
);

"Transaction pending forever"

Check gas settings or speed up:

await wallet.sendTransaction({
  ...tx,
  maxFeePerGas: tx.maxFeePerGas * 120n / 100n,
});

Security Checklist

• Never expose private keys
• Validate contract addresses
• Sanitize user inputs
• Use proper error boundaries
• Implement CSP headers

Cross-References

• Bonded Agent: 05-web3-frontend
• Related Skills: ethereum-development, solidity-development

Version History

Version	Date	Changes
2.0.0	2025-01	Production-grade with wagmi v2, viem
1.0.0	2024-12	Initial release