Token Vendor dApp

An Ethereum-based decentralized application (dApp) that allows users to seamlessly buy and sell ERC-20 tokens (Token G9) in exchange for ETH using a vendor smart contract and an ERC-20 contract.

🌐 Live Demo

Please visit the live demo at group9-evm.vercel.app.

📦 Stack

• Frontend: Next.js 15, TailwindCSS, DaisyUI
• Wallet Integration: Reownkit, wagmi, viem
• Smart Contracts: Solidity, Hardhat, OpenZeppelin
• Deployment: Vercel (frontend), Sepolia testnet (contracts)

📸 Diagrams

System Architecture

User Flow – Buy/Sell

Contract Interaction

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🚀 Features

• Buy tokens by sending ETH to the Vendor contract
• Sell tokens back to the contract in exchange for ETH
• Real-time balances for ETH and tokens
• Wallet integration via Reownkit for seamless Web3 experience

🧪 Local Development

Clone and install dependencies:

git clone https://github.com/segment7/token-vendor.git
cd token-vendor
yarn install

Run the local blockchain and deploy:

# Start local Hardhat chain
yarn chain

# Deploy contracts
yarn deploy

Start the frontend:

yarn start

Access at http://localhost:3000

📄 Contracts

• TokenG9.sol – Custom ERC-20 token, initial supply: 1000 G9 tokens
• Vendor.sol – Vendor contract with the following key functions:
  • buyTokens() (payable)
  • sellTokens()
  • withdraw() (owner only)

Events:

• BuyTokens (buyer, ethAmount, tokenAmount)
• SellTokens (seller, ethAmount, tokenAmount)

🙏 Acknowledgments

• Scaffold-ETH 2 - Open-source Ethereum dapps toolkit

✍️ Author

Created and customized by Group 9
Built with 💙 for the EVM Bootcamp

📄 License

• AGPL v3