DeSwag
A swag NFC check, previous ETHGlobal attendees can trade and/or sell swag.
Demo
About
Attendees tap an NFC chip in order to create their crypto wallet at event booths to claim swag. Prevents duplicate claims and gives booths real-time distribution data, permitting them to track supply and gauge supply needed for future events. A built-in marketplace lets participants trade past swag items.
How it's made
Frontend: Next.js 15 with TypeScript and TailwindCSS for fast, responsive UI. UI/UX: Custom pastel gradient theme, reusable React components (ProductCard, GetStartedForm, etc.). Authentication: Coinbase CDP Hooks + AuthButton for wallet login, user session management, and EVM address retrieval. Smart Contracts: Solidity contracts on Ethereum testnet (via Coinbase developer platform) to handle swag ownership, listing, and transfers. NFC Integration: NFC codes are mapped to wallet addresses using a custom utility (saveWalletNfc, getNfcByWallet) so physical swag can be linked to on-chain identity. Database / API: Supabase and Walrus to persist NFC ↔ wallet mappings and listing data, exposed through serverless API routes. Payments: ETH-denominated listing & purchase flows powered by Coinbase SDK. Deployment: Hosted on Vercel with environment variables managed via .env.