TicketVault

TicketVault is a production-grade decentralized ticketing platform built on Aptos blockchain that solves critical industry problems: fraud, scalping, and blockchain adoption barriers. It implements a 'Web 2.5' hybrid architecture where tickets are NFTs with verifiable ownership, buyers enjoy gasless transactions via a relayer service, and venue staff can validate tickets offline using cryptographically signed JWT QR codes. Post-event, tickets transform into collectible digital souvenirs. The platform includes three specialized frontends (organizer dashboard, buyer marketplace, redeemer PWA), a robust Express backend with AI-powered analytics concierge, and a Move smart contract managing the complete ticket lifecycle with state transitions (LOCKED → ADMITTED → SOUVENIR).

• Architected a Web 2.5 hybrid system combining Web2 UX (gasless, familiar flow) with Web3 security (blockchain-based ownership, immutability).
• Implemented true gasless transactions using a relayer account pattern where the backend sponsors all on-chain operations, abstracting blockchain complexity from end users.
• Designed an offline-first redemption system using RSA-signed JWTs in QR codes, enabling venue staff to cryptographically verify ticket authenticity without internet connectivity.
• Built three distinct Next.js applications for three user personas (Organizer, Buyer, Redeemer) with role-specific UX optimizations and security constraints.
• Created a Move smart contract with a state machine pattern for tickets (STATE_LOCKED → STATE_ADMITTED → STATE_SOUVENIR) to manage the complete event lifecycle.
• Implemented MongoDB as a high-speed cache layer mirroring on-chain data, enabling sub-second query responses while maintaining blockchain as the single source of truth.
• Developed a template-based NLQ (Natural Language Query) AI Concierge using regex and MongoDB aggregation pipelines to provide organizers with instant analytics insights.
• Established comprehensive security layers: rate limiting (general/auth/CAPTCHA/minting), NoSQL injection prevention, input sanitization, and role-based access control.
• Used RSA public/private key cryptography for JWT signatures, allowing distributed offline verification while maintaining centralized trust anchor.
• Designed the Redeemer app as a Progressive Web App (PWA) for offline-first operation, enabling reliable ticket validation even in poor network conditions at venues.

1. Designed the complete system architecture with three-layer separation: Frontend (Next.js) → Backend (Express) → Blockchain (Aptos).
2. Implemented the Move smart contract with comprehensive ticket lifecycle management and authorization patterns.
3. Built the RelayerService for true gasless transactions, using a pre-funded Aptos account to sponsor all user operations.
4. Developed the JWT-based offline verification system with RSA key pair generation and secure public key distribution.
5. Created the AI Concierge with 6 pre-defined query templates and dynamic MongoDB aggregation pipeline generation.
6. Implemented multi-layer security: sanitization middleware, rate limiters (4 tiers), and CAPTCHA integration for bot prevention.
7. Built the Organizer dashboard with real-time analytics, redeemer authorization, and event management capabilities.
8. Developed the Buyer marketplace with wallet integration (Petra/Martian), CAPTCHA-protected minting, and NFT ticket visualization.
9. Created the Redeemer PWA with QR code scanning, offline JWT verification, and batch syncing for redemptions.
10. Established a formal API contract (OpenAPI 3.0) defining all endpoints, request/response schemas, and error codes.
11. Implemented comprehensive error handling, logging, and monitoring infrastructure for production readiness.