MesaCompartida

Problem Statement

Mesa Compartida is a blockchain-powered food voucher system that solves three problems simultaneously: food waste, local hunger, and disconnected global aid.Here's how it works: María, a home cook in Bogotá, has 3 extra arepas. She lists them as vouchers for $5 each on Mesa Compartida. Jacques, living in France, wants to help someone in Latin America eat today. He buys a voucher with MiniPay and gifts it to Pedro, a person experiencing homelessness in Bogotá. Pedro shows the voucher QR code at María's home, receives his meal, and our smart contract instantly releases payment to María.This isn't a traditional food marketplace—it's a voucher redemption system. Donors anywhere in the world can purchase meal vouchers and gift them to people in need. Providers (home cooks and restaurants with surplus food) receive guaranteed payment held in escrow until redemption. Beneficiaries get hot, homemade meals with dignity.The key innovation: by using vouchers instead of direct sales, we eliminate regulatory friction around informal food sales, enable transparent charitable giving, and create verifiable on-chain impact metrics. Every donation is traceable. Every meal is accountable. Zero overhead goes to middlemen—95% of donations reach providers directly.

Solution

Architecture Overview Mesa Compartida is built as a full-stack decentralized application with three core components:1.⁠ ⁠Smart Contract Layer (Solidity + Hardhat)VoucherEscrow.sol: Core contract managing voucher lifecycleEscrow mechanism: Funds locked when voucher is purchased, released upon redemption confirmationEvents emitted: VoucherCreated, VoucherPurchased, VoucherRedeemed, VoucherExpiredSecurity features: Reentrancy guards, time-based expiration, fraud preventionDeployed and verified on Celo Mainnet2.⁠ ⁠Mobile Application (MiniApp in MiniPay)Three user flows: Providers, Donors, and BeneficiariesMiniPay SDK integration for seamless wallet connection and paymentsQR code generation/scanning for redemption verificationReal-time order tracking and notificationsOptimized for low-bandwidth environments (critical for LATAM users)3.⁠ ⁠Identity & Reputation (ENS Integration)Subdomain system: maria.mesacompartida.ethOn-chain reputation tied to ENS names (ratings, successful deliveries, trust score)Portable identity: providers own their reputation even if platform disappearsFirst 100 active providers receive free ENS subdomains🔧 TECHNOLOGIES USED Primary Stack: Celo / MiniPay: Blockchain infrastructure and wallet Hardhat: Smart contract development and testing ENS (Ethereum Name Service): Decentralized identity and reputationSupporting Technologies: Solidity: Smart contract language Next.js: Mobile app framework IPFS: Decentralized storage for food images The Graph (planned): For indexing voucher events and impact dashboard💡 NOTABLE HACKS AND INNOVATIONS 1.⁠ ⁠Voucher Model Over Marketplace Most food-sharing platforms are marketplaces where users buy food for themselves. We flipped this: donors buy vouchers to gift to others. This simple shift unlocks:Legal clarity (donation vs. commercial sale)Global donor reach (anyone can help anyone)Transparent impact measurement (vouchers = provable meals delivered)2.⁠ ⁠Three-Actor System on One PlatformWe designed for three distinct user types with different needs:Providers: Want guaranteed payment, simple listingDonors: Want transparency and ease of giving Beneficiaries: Need zero-friction redemption (no special configuration with wallets required)