WorldPay

Problem Statement

WorldPay is a Next.js-based Mini App that enhances the World App wallet to deliver secure, cost-efficient cross-border remittances for the $800B+ market plagued by 5-7% fees and 10-20% fraud. Built for Worldcoin’s ecosystem, it leverages World ID for sybil-resistant verification (ensuring unique human senders/recipients), 1inch for DeFi rate optimization (saving 1-3% on fees), and ENS for user-friendly recipient addresses (e.g., "bob.eth"). Deployed on World Chain Sepolia (Chain ID 4801), it utilizes zero-fee transactions for instant, trustless settlements. Users sign in with World ID, input payment details, view optimized rates, and send securely via the World App wallet, with all transactions logged transparently on-chain. WorldPay extends World App’s basic P2P payments by adding fraud prevention and cost savings, targeting 23M+ users and 280M+ global migrants. The demo simulates 50 transfers, blocks sybil attempts, and showcases fee reductions, aligning with financial inclusion goals for underserved regions (Africa, SEA, LatAm).

Solution

WorldPay is a prototype Next.js 14 (TypeScript) frontend Mini App, built in ~48 hours for ETHGlobal New Delhi 2025, designed to enhance the World App wallet for secure, optimized cross-border remittances. We focused on integrating the Worldcoin MiniKit SDK (@worldcoin/minikit-js) to enable World ID authentication and payment initiation, leveraging World Chain Sepolia (Chain ID 4801) for zero-fee transactions. The frontend, styled with Tailwind CSS and shadcn/ui components, features a responsive UI with a sign-in screen (using MiniKit.auth for World ID verification in staging mode) and a basic transfer form (amount, recipient input). We planned to integrate 1inch Fusion SDK (@1inch/fusion-sdk) for real-time DeFi rate optimization (USDC/WLD swaps, targeting 1-3% fee savings) and ensjs for ENS name resolution (e.g., "bob.eth" to address), but these are mocked for the demo due to time constraints. Zustand manages global state (user auth, mock rates), and React Hook Form handles input validation. The backend, planned as Next.js API routes, includes stubs for /api/auth (World ID verification), /api/optimize (1inch quotes), and /api/ens (ENS resolution), with mock responses to simulate the flow. Partner technologies:Worldcoin MiniKit: Enabled rapid World ID auth and payment triggers, saving ~4 hours of integration time. World Chain: Provides zero-fee txns, aligning with our remittance cost-saving goal. 1inch (Planned): Mocked rate optimization to show fee reductions in the demo. ENS (Planned): Mocked name-to-address resolution for user-friendly UX.Notable Hack: We used mock World ID proofs and 1inch responses to simulate a full remittance flow (login → input → rates → send) within the hackathon’s time limit, bypassing API rate limits. The app is deployed on Vercel for a live demo, open-sourced on GitHub, and tested with mock transfers, showcasing sybil-resistant payments via World ID. Future iterations will complete 1inch and ENS integrations and add Self SDK for compliance proofs.