LangDAO

Problem Statement

LangDAO is a decentralized language exchange platform where users can instantly talk, teach, and earn with PyUSD, PayPal’s programmable stablecoin. It transforms traditional, centralized language learning into a borderless, peer-to-peer communication economy, removing banks, middlemen, and friction entirely. Tutors and learners connect directly using smart contracts that ensure instant, trustless PyUSD payments—no delays, no high fees, no bank accounts required.Unlike platforms like italki or Baselang—where tutors are overbooked or locked behind costly subscriptions—LangDAO allows learners to start a real conversation with a native speaker instantly and pay only for the minutes they use. Built on blockchain, the system replaces bureaucracy with verifiable trust, while providing transparent micropayments that empower users globally.All you need is a phone, an internet connection, and your voice. LangDAO unlocks earning potential for millions of native speakers—especially the global majority of unbanked or underemployed graduates—by turning language skills into income. By leveraging PyUSD’s instant, inclusive, programmable payments, LangDAO reimagines learning as both human connection and economic freedom.

Solution

I'll analyze the project structure and provide comprehensive technical details for your hackathon description. Let me examine the codebase to understand the full scope of the project.[5 tools called]Based on my comprehensive analysis of the LangDAO project, here are the technical details for your hackathon description:LangDAO - Technical Project Details🎯Project OverviewLangDAOis a decentralized language learning platform that enables people worldwide to use their language skills to teach, learn, and earn crypto in Web3. The platform focuses on real-time video sessions with per-second billing, creating a sustainable economy for language education.🏗️Technical ArchitectureFrontend StackFramework: Next.js 15.2.3 with React 19Web3 Integration:Wagmi 2.16.4 + Viem 2.34.0 for Ethereum interactionsRainbowKit 2.2.8 for wallet connectionThirdweb 5.109.0 for additional Web3 functionalityUI/UX: Tailwind CSS + DaisyUI for modern, responsive designState Management: Zustand for client-side stateReal-time: Socket.io for live communicationSmart Contract LayerLanguage: Solidity ^0.8.0Network: Ethereum Sepolia TestnetContract Address:0x4Fb5675e6baE48C95c1D4f1b154E3d5e8E36112CToken: PYUSD (PayPal USD) for paymentsKey Features:Per-second billing systemMulti-language support (38 languages)Session lifecycle managementAutomatic payment processingStudent/tutor registration systemWebRTC Video InfrastructureTechnology: Custom WebRTC implementationFeatures:Real-time video/audio communicationSession chat with timestampsCross-user status synchronizationHeartbeat monitoring (10-second intervals)Professional UI with role badgesMulti-language support (16 languages)Deployment: Railway.app production environmentSecurity: HTTPS/WSS protocols with automatic detectionBackend ServicesArchitecture: Serverless/lightweight servicesWebSocket Server: Node.js for real-time signalingEvent System: HTTP POST endpoints for session trackingHeartbeat Service: 10-second interval monitoringIntegration: RESTful APIs for contract interactions🔧Core Technical Features1. Smart Contract Functionality// Key contract functions - registerStudent(targetLanguage, budgetPerSec) - registerTutor(languages[], ratePerSecond) - depositFunds(amount) // PYUSD only - startSession(tutorAddress, language) - endSession(tutorAddress) - hasSufficientBalance(student, tutor)2. Real-time Payment SystemPer-second billingduring active sessionsAutomatic session terminationon disconnectPYUSD token integrationfor stable paymentsBalance validationbefore session startRefund systemfor unused funds3. Multi-language Support38 supported languageswith ISO 639-1 codesLanguage-specific tutoring ratesStudent target language matchingTutor language capability verification4. Session ManagementSession lifecycle tracking(start, active, end)Real-time cost calculationAutomatic payment processingSession history and analyticsEmergency session termination🌐Web3 IntegrationWallet SupportMetaMask, WalletConnect, Coinbase WalletLedger, Rainbow Wallet, Safe WalletBurner wallet for local developmentNetwork ConfigurationPrimary: Sepolia TestnetDevelopment: Hardhat local networkRPC: Alchemy integration with fallbacksToken EconomicsPayment Token: PYUSD (PayPal USD)Token Address:0xCaC524BcA292aaade2DF8A05cC58F0a65B1B3bB9Stablecoin integrationfor predictable pricing📱User Experience FeaturesStudent FlowWallet Connection→ Role SelectionRegistration→ Language & Budget SetupDeposit Funds→ PYUSD token approvalFind Tutor→ Matchmaking systemStart Session→ WebRTC video callReal-time Billing→ Per-second paymentsSession End→ Automatic settlementTutor FlowWallet Connection→ Role SelectionRegistration→ Languages & Rates SetupGo Online→ Availability statusAccept Sessions→ Student matchingTeach Session→ WebRTC video callReceive Payments→ Real-time earnings🔒Security & ReliabilitySmart Contract SecurityAccess controlwith role-based modifiersInput validationfor all functionsEmergency functionsfor owner interventionBalance checksbefore operationsWebRTC SecurityHTTPS/WSS protocolsfor secure communicationEnd-to-end encryptionfor video/audioSession token validationHeartbeat monitoringfor connection health🚀Deployment & InfrastructureFrontend DeploymentFramework: Next.js with static generationHosting: Vercel-ready configurationEnvironment: Production-optimized buildsBackend DeploymentPlatform: Railway.appURL:https://langdao-production.up.railway.appWebSocket: Real-time signaling serverAPI: RESTful endpoints for integrationSmart Contract DeploymentNetwork: Sepolia TestnetVerification: Etherscan-readyABI: Auto-generated TypeScript interfaces📊Technical MetricsPerformanceReal-time billing: Per-second accuracyVideo latency: WebRTC optimizedTransaction speed: Ethereum network dependentHeartbeat frequency: 10-second intervalsScalabilityMulti-language support: 38 languagesConcurrent sessions: Limited by WebRTC infrastructureUser capacity: Wallet-based authenticationPayment processing: PYUSD token efficiency🛠️Development ToolsSmart Contract DevelopmentHardhat: Development frameworkTypeScript: Type safetyEthers.js: Contract interactionsOpenZeppelin: Security standardsFrontend DevelopmentNext.js: React frameworkTailwind CSS: Utility-first stylingFramer Motion: AnimationsReact Query: Data fetchingTesting & QualityESLint: Code lintingPrettier: Code formattingTypeScript: Type checkingHot reload: Development efficiency🎯Hackathon AchievementsCompleted Features✅Full-stack Web3 application✅Real-time video communication✅Per-second billing system✅Multi-language support✅PYUSD token integration✅Professional UI/UX✅Production deployment✅Smart contract verificationTechnical InnovationPer-second billingfor language learningWebRTC + Web3 integrationfor real-time paymentsMulti-language matching algorithmAutomatic session managementStablecoin payment systemThis technical foundation positions LangDAO as a comprehensive, production-ready platform for decentralized language education with real-time payments and professional-grade video communication.