Capital

Capital is a secure, scalable, and modern event ticketing platform, developed as part of a final-year BE project. It addresses critical challenges in traditional ticketing systems, including:

• Ticket Fraud
• Duplicate Entries
• Unauthorized Reselling

Capital achieves this through a hybrid architecture that combines centralized orchestration with decentralized cryptographic primitives, eliminating inefficiencies in legacy QR-only systems and blockchain-heavy platforms.

🚀 How Capital Solves the Problems

1. Unauthorized Resale

• In legacy platforms like EventOrchestr8, tickets were just QR payloads → easily forwarded/resold.
• Capital issues cryptographically signed tickets bound to a user’s account (via Ed25519).
• Even if the QR is forwarded, validation fails unless presented by the legitimate account owner.
• Result: Unauthorized resale eliminated.

2. Redundant Blockchain Usage & Gas Fees

• EventOrchestr8 stored tickets on Ethereum → high gas fees & slow validation.
• Capital uses a centralized backend as the authoritative record, while still leveraging cryptographic signing for trust.
• Blockchain is optional (for audit logs), not mandatory.
• Result: No gas fees, faster validation.

3. Refunds & Event Cancellations

• Blockchain-based ticketing makes refunds/cancellations difficult.
• In Capital, the backend updates ticket states instantly (refunded, canceled, redeemed).
• Organizers handle real-world contingencies in real-time.
• Result: Flexible and practical refund management.

4. Third-Party Dependence (Firebase, Wallets)

• EventOrchestr8 relied heavily on Firebase → external dependency risks.
• Capital uses a custom backend in TypeScript with internal wallets and webhooks.
• Result: Improved control, better data integrity, minimal third-party reliance.

5. Scalability

• Capital leverages Ed25519 cryptographic verification (microsecond-level).
• Validation is near-instant, scalable for stadium-scale events.
• Tickets are atomically locked post-redemption → one-time use guaranteed.
• Result: High-throughput, real-time validation.

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🛠️ Technology Stack

Backend	Frontend	DevOps / Tooling
Node.js	Next.js	TypeScript
Express.js	React.js	GitHub Actions (CI/CD)
Prisma	React Router DOM	Biome (lint/format)
PostgreSQL	React Query	Vitest (testing)
Redis / Redis Queue	Zustand	Resend (emails)
WebSocket	Tailwind CSS	Prometheus
Libsodium (encryption)	Shadcn/UI	Grafana & Loki
Decimal.js	Storybook	GitOps (infra)
Supabase (storage)		Scaling + Stress Testing
Docker, Nginx, Kubernetes

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🏗️ System Architecture

The platform integrates centralized orchestration with decentralized cryptographic primitives.

• Centralized Backend – Authoritative source of truth (PostgreSQL + Redis).
• Decentralized Cryptography – Ed25519 ensures ticket authenticity.
• Three-Queue Mechanism – Pending, In-progress, Failed (Dead-letter).
• Redis – Caching, concurrency control, pub/sub for validators.
• Validators – Mobile/kiosk apps verifying tickets in real-time.

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🎫 Ticket Lifecycle

1. Discovery → Users browse events (cached with Redis).
2. Purchase → System issues signed ticket payload embedded in a QR code.
3. Storage → Tickets securely stored in user’s account wallet.
4. Redemption → Validator scans QR → backend verifies signature & ownership.
5. Refunds/Cancellations → Organizer updates backend state instantly.

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🔒 Security Highlights

• Bcrypt – Secure password hashing (salt + cost factor).
• Ed25519 – Digital signatures for ticket authenticity.
• Four-Layer Encryption – Canonical serialization + timestamping for replay prevention.
• JWT + Redis-backed Refresh Tokens – Device-specific, short-lived, tamper-resistant sessions.
• TLS Everywhere – Encrypted communication between clients, validators, and backend.
• Immutable Audit Logs – Forensics & fraud prevention.
• Rate-Limiting & Anomaly Detection – Protection against DoS/fraud attacks.
• Hardware-backed Vaults – Secure key management.

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📊 Scalability & Performance

• Node.js clustering → Utilizes multi-core CPU for parallel validation.
• Kubernetes auto-scaling → Handles fluctuating workloads.
• Redis replication → Ensures distributed state consistency.
• Microsecond Ed25519 signature checks → Thousands of ticket validations/sec.
• Cloud-native deployment → Elastic, fault-tolerant, globally scalable.

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🔑 Key Aspects

• Liquidity Pooling – Event earnings are pooled securely, enabling transparent settlements for organizers post-event.
• Organizer’s Role & Earnings – Each organizer has a dedicated wallet. Earnings are credited after event completion (post-refunds).
• Refund Mechanism – Flexible, organizer-approved refunds update wallet balances and ticket states in real time.
• Scaling – Supports both vertical (Node.js clustering) and horizontal (Kubernetes) scaling to handle high-demand events.
• Custom Transaction System – Inspired by Razorpay, Capital implements an in-house wallet and payment processing layer with deposits, withdrawals, payouts, and webhook-driven reconciliation.

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🤝 Contributing

We welcome contributions! Please fork the repository and submit a pull request with your improvements. Ensure reading Contributor.md

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🛠️ Getting Started

1. Clone the Repository

git clone https://github.com/your-username/capital.git
cd capital

2. Install Dependencies

npm install

3. Configure Environment

Create a .env file:

DATABASE_URL=postgresql://user:password@localhost:5432/capital
REDIS_URL=redis://localhost:6379
SUPABASE_URL=...
SUPABASE_KEY=...
RESEND_API_KEY=...

4. Run with Docker Compose

docker-compose up --build

5. Run Locally (Dev Mode)

npm run dev

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📜 License

This project is licensed under the MIT License.

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