Concert Ticket Resale Smart Contract

A decentralized marketplace for minting, buying, selling, and transferring concert tickets on the Stacks blockchain using Clarity smart contracts.

Overview

This smart contract provides a complete ticketing solution that prevents fraud, enables secure resales, and automates platform fee collection. Tickets are stored on-chain with full provenance tracking from minting to usage.

Key Features

🎫 Ticket Management

• Mint Tickets: Create tickets with event details, pricing, dates, and seat information
• Use Tickets: Mark tickets as used to prevent double-spending
• Transfer Tickets: Gift or send tickets to other users
• Track History: Full ownership and transaction history

💰 Marketplace

• List for Resale: Set custom resale prices for your tickets
• Buy Tickets: Purchase listed tickets with automatic payment splitting
• Cancel Listings: Remove tickets from marketplace anytime
• Platform Fees: Automated 5% fee collection (configurable by admin)

🔒 Security Features

• Expiration validation (can't sell/use expired tickets)
• Usage prevention (can't resell used tickets)
• Ownership verification on all operations
• Self-transfer prevention
• Emergency pause mechanism
• Input validation on all user data

Data Structure

Each ticket contains:

{
    event-name: string (max 100 chars)
    original-owner: principal
    current-owner: principal
    original-price: uint
    resale-price: uint
    for-sale: bool
    event-date: uint (block height)
    seat-section: string (max 50 chars)
    used: bool
}

Core Functions

User Functions

mint-ticket

Create a new ticket.

(mint-ticket 
    (event-name (string-ascii 100))
    (price uint)
    (event-date uint)
    (seat-section (string-ascii 50)))

Returns: (ok ticket-id)

list-for-resale

List your ticket on the marketplace.

(list-for-resale (ticket-id uint) (resale-price uint))

Returns: (ok true)

buy-ticket

Purchase a listed ticket. Automatically transfers payment minus platform fee to seller.

(buy-ticket (ticket-id uint))

Returns: (ok true)

cancel-listing

Remove your ticket from the marketplace.

(cancel-listing (ticket-id uint))

Returns: (ok true)

use-ticket

Mark your ticket as used (event check-in).

(use-ticket (ticket-id uint))

Returns: (ok true)

transfer-ticket

Gift or transfer your ticket to another user.

(transfer-ticket (ticket-id uint) (recipient principal))

Returns: (ok true)

Read-Only Functions

get-ticket

Retrieve ticket information.

(get-ticket (ticket-id uint))

Returns: (optional ticket-data)

get-user-tickets

Get all ticket IDs owned by a user.

(get-user-tickets (user principal))

Returns: (list uint)

get-event-tickets

Get all ticket IDs for a specific event.

(get-event-tickets (event-name (string-ascii 100)))

Returns: (list uint)

calculate-resale-fee

Calculate platform fee for a given price.

(calculate-resale-fee (price uint))

Returns: uint

Admin Functions

set-platform-fee

Update the platform fee percentage (max 20%).

(set-platform-fee (new-fee uint))

Requires: Contract owner only

toggle-pause

Pause/unpause the contract for emergency situations.

(toggle-pause)

Requires: Contract owner only

validate-event

Pre-approve event names for additional security.

(validate-event (event-name (string-ascii 100)))

Requires: Contract owner only

emergency-withdraw

Withdraw accumulated platform fees.

(emergency-withdraw (amount uint))

Requires: Contract owner only

Error Codes

Code	Constant	Description
u100	err-owner-only	Action requires contract owner
u101	err-not-found	Ticket doesn't exist
u102	err-unauthorized	Not the ticket owner
u103	err-already-sold	Ticket already sold
u104	err-not-for-sale	Ticket not listed for sale
u105	err-insufficient-payment	Payment amount too low
u106	err-expired	Event date has passed
u107	err-invalid-price	Price is zero or invalid
u108	err-already-used	Ticket already used
u109	err-transfer-failed	STX transfer failed
u110	err-invalid-input	Invalid input data
u111	err-self-transfer	Cannot transfer to self

Usage Example

;; 1. Mint a ticket
(contract-call? .ticket-resale mint-ticket 
    "Coldplay World Tour 2025" 
    u1000000 
    u15000 
    "Section A, Row 5")

;; 2. List ticket for resale
(contract-call? .ticket-resale list-for-resale u1 u1200000)

;; 3. Buy a listed ticket
(contract-call? .ticket-resale buy-ticket u1)

;; 4. Use ticket at event
(contract-call? .ticket-resale use-ticket u1)

;; 5. Check ticket details
(contract-call? .ticket-resale get-ticket u1)

Payment Flow

When a ticket is purchased on the resale market:

1. Buyer sends full resale price in STX
2. Platform fee (5%) is transferred to contract owner
3. Remaining amount (95%) is transferred to seller
4. Ticket ownership is transferred to buyer
5. Ticket is removed from marketplace

Example: For a 100 STX ticket:

• Seller receives: 95 STX
• Platform receives: 5 STX

Security Considerations

✅ Tested Validations:

• All string inputs are validated for non-empty content
• Event dates must be in the future
• Prices must be greater than zero
• Ticket ownership verified on all operations
• Used tickets cannot be resold or transferred
• Expired tickets cannot be sold or used

✅ Best Practices:

• Use tickets before event expiration
• Cancel listings before transferring tickets
• Verify ticket details before purchasing
• Check event dates match your expectations