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DeSwag

A swag NFC check, previous ETHGlobal attendees can trade and/or sell swag.

DeSwag

Created At

ETHGlobal New York 2025

Project Description

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.

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