Build Your First Web3 DApp: Complete Tutorial 2026
Build a DApp by: 1) Set up React + wagmi/viem 2) Connect wallet with ConnectKit/RainbowKit 3) Read contract state with hooks 4) Write transactions with proper error handling 5) Deploy contract and frontend.
Key Insight
Build a DApp by: 1) Set up React + wagmi/viem 2) Connect wallet with ConnectKit/RainbowKit 3) Read contract state with hooks 4) Write transactions with proper error handling 5) Deploy contract and frontend.
Introduction
This tutorial walks through building a complete Web3 DApp from scratch. We will create a simple voting app that connects wallets, reads blockchain state, and submits transactions.
Prerequisites
- Node.js 18+
- Basic React knowledge
- MetaMask browser extension
- Sepolia testnet ETH (from faucet)
Project Setup
Create a new Next.js project with TypeScript and Tailwind. Install wagmi, viem, tanstack/react-query, and connectkit.
Configure Wagmi
Create a wagmi config with your chains (mainnet, sepolia) and transports. Use getDefaultConfig from connectkit for easy setup.
Wrap App with Providers
Wrap your app with WagmiProvider, QueryClientProvider, and ConnectKitProvider.
Connect Wallet Button
Use ConnectKitButton component for easy wallet connection.
Read Contract Data
Use useReadContract hook from wagmi to read blockchain state. Provide contract address, ABI, and function name.
Write to Contract
Use useWriteContract hook for transactions. Handle pending, confirming, and success states. Use useWaitForTransactionReceipt to wait for confirmation.
Testing
- Get Sepolia ETH from faucet
- Connect MetaMask to Sepolia
- Test wallet connection
- Test reading and writing
- Verify on Etherscan
Production Checklist
- Test on testnet thoroughly
- Audit smart contract
- Set up error monitoring
- Configure proper RPC endpoints
- Deploy to production L2
Conclusion
You have built a functional Web3 DApp! Key concepts: wagmi hooks for blockchain interaction, ConnectKit for wallets, and proper transaction handling. Expand this foundation to build more complex applications.
Key Takeaways
- Use viem/wagmi for modern Web3 development
- ConnectKit or RainbowKit for wallet connections
- Read operations are free, writes cost gas
- Always handle transaction failures gracefully
- Test on testnets before mainnet deployment
Frequently Asked Questions
Do I need to know Solidity?
For building frontends, you can interact with existing contracts without Solidity knowledge. To create your own contracts, you will need to learn Solidity basics.
Which network should I start with?
Start with Sepolia testnet for Ethereum development. It is free (faucet ETH) and behaves like mainnet. Move to mainnet or L2s like Base when ready for production.
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About the Author
Marcus Williams
Blockchain Developer & DeFi Strategist
MS Financial Engineering, Columbia | Former VP at Goldman Sachs
Marcus Williams is a blockchain developer and DeFi strategist with a decade of experience in fintech and decentralized systems. He earned his MS in Financial Engineering from Columbia University and spent five years at Goldman Sachs building quantitative trading platforms before pivoting to blockchain full-time in 2019. Marcus has audited smart contracts for protocols managing over $2 billion in total value locked and has contributed to open-source projects including Uniswap and Aave governance tooling. At Web3AIBlog, he specializes in DeFi protocol analysis, tokenomics deep dives, and blockchain security reviews. His writing bridges the gap between traditional finance and the decentralized economy.
