UseOnce Pallet - Ticket Management System on Substrate

A blockchain-based ticket management system implementing single-use tickets with state transitions controlled through authorized accounts.

Overview 📖

This Substrate pallet (useonce) provides a secure framework for:

• Immutable ticket registration on-chain
• Role-based access control for state modifications
• Final state transition to prevent replay attacks

Key Features 🔑

• On-Chain Ticket Registry
  Permanent record of all ticket issuances with cryptographic proof
• Granular Authorization
  Multi-level account privileges using Substrate's origin system
• State Machine Enforcement
  Strict lifecycle: Registered → Consumed (with audit trail)
• Light Client Compatible
  Designed for easy integration with frontend applications

Technical Architecture 🧠

pub enum TicketState {
    Registered,  // Initial state
    Consumed     // Terminal state
}

impl<T: Config> Pallet<T> {
    // Core state transition logic
    fn consume_ticket(ticket_id: T::Hash) -> DispatchResult {
        // Authorization checks
        // State validation
        // Immutable update
    }
}

Installation 🛠️

Prerequisites

• Rust 1.68+ (rustup install stable)
• Node.js 16.x+ (LTS recommended)

Node Setup

# Clone repository
git clone https://github.com/zeel991/substrate-node-template.git
cd substrate-node-template

# Build optimized binary
cargo build --release --features runtime-benchmarks

# Launch development node
./target/release/node-template \
  --dev \
  --base-path /tmp/node \
  --ws-port 9944

Frontend Demo Setup (Separate Terminal)

cd substrate-demo

# Install dependencies
yarn build

# Start interactive demo
yarn demo 

Usage Examples 💻

1. Issue New Ticket (Sudo)

const ticketId = api.createType('Hash', crypto.randomBytes(32));
await api.tx.useOnce.createTicket(ticketId).signAndSend(alice);

2. Consume Ticket (Authorized Account)

const stateUpdate = api.tx.useOnce.consumeTicket(ticketId);
await stateUpdate.signAndSend(authorizedBob, { nonce: currentNonce });

3. Verify Ticket State

const ticket = await api.query.useOnce.tickets(ticketId);
console.log(`Ticket ${ticketId.toHex()} state: ${ticket.state.toString()}`);

Testing 🧪

Run comprehensive test suite:

# Unit tests
cargo test -p useonce-pallet

# Integration tests
cargo test --test integration

Security Model 🔒

• Authorization: Only pre-approved accounts can modify state
• Finality: Once consumed, tickets cannot be reverted
• Nonce Protection: Replay attack prevention through transaction numbering