DeFiTickets: HoliFest Ticket Sale dApp

An Ethereum ticketing dApp for a festival: buy, swap and resell tickets on Sepolia through a Solidity contract and a Next.js front end.

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Overview

DeFiTickets is a decentralized ticket sale for the "HoliFest Festival 2024" event, as titled in the UI. A single TicketSale contract records who owns which ticket, takes payment in ETH, lets holders swap tickets with each other, and runs a resale market that sends a 10% service fee to the event manager. The Next.js front end connects a wallet through Web3Modal and calls the contract with ethers.js.

The project was built as a blockchain course assignment. Earlier versions of this README called it a "Tihar" ticket sale, but the code and UI are branded HoliFest.

Features

• Primary sale: buy any unsold ticket ID at the base price. Each address can hold one ticket, and the payment must match the price exactly.
• Ticket swaps: offer a swap on another holder's ticket. That holder can accept, and the contract swaps ownership.
• Resale market: list your ticket at a price. A buyer pays the listed amount, the seller gets 90% and the manager gets 10%.
• Lookup and validation: find the ticket ID for any wallet address, or check whether a ticket ID is owned and listed for resale.
• Day-wise labels: the UI maps ticket ID ranges to festival days (Monday to Friday, plus Weekend).
• Manager controls: only the deployer can update the ticket price or add tickets. The contract enforces this.
• Live activity feed: the UI subscribes to TicketPurchased, TicketSwapped and TicketResold events.
• Statistics: counts of total, sold and available tickets.

Tech stack

Layer	Technology
Smart contract	Solidity ^0.8.17 (contracts/TicketSale.sol)
Tooling	Hardhat, hardhat-toolbox, Chai, dotenv
Front end	Next.js 14 (pages router), React 18, CSS Modules
Wallet / chain	Web3Modal 1.x, ethers.js v5, Sepolia testnet

Architecture

flowchart LR
    U[Next.js UI] -->|Web3Modal| W[Browser wallet]
    W -->|ethers.js| C[TicketSale contract on Sepolia]
    H[Hardhat deploy script] -->|INFURA_URL + PRIVATE_KEY| C
    H --> CFG[config.json]

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Contract API

Function	Access	Description
buyTicket(ticketId)	payable	Buy an unsold ticket at ticketPrice
getTicketOf(address)	view	Ticket ID owned by an address (0 if none)
offerSwap(ticketId) / acceptSwap(ticketId)	public	Two-step ticket swap
resaleTicket(price) / acceptResale(ticketId)	public / payable	List your ticket, or buy a listed one (10% fee to manager)
checkResale() / getAvailableTickets()	view	IDs listed for resale / unsold IDs
getTicketDetails(ticketId)	view	Owner, resale flag and resale price
updateTicketPrice(newPrice) / addTickets(n)	manager	Change price / add supply

Project structure

contracts/TicketSale.sol    # Smart contract
scripts/deploy.js           # Deploys 100 tickets at 0.001 ETH, writes config.json
scripts/compile.js          # Standalone solc compile helper
test/TicketSale.test.js     # Hardhat + Chai tests
pages/index.js              # Entire dApp UI
styles/                     # CSS Modules + globals
ganache-test.js             # Manual script against a local Ganache node (port 7545)
hardhat.config.js

Getting started

Prerequisites: Node.js 18+, MetaMask (or another wallet Web3Modal supports), and Sepolia ETH.

git clone https://github.com/abhiishek340/DeFiTickets.git
cd DeFiTickets
npm install

Create a .env file for deployment:

Variable	Description
INFURA_URL	Sepolia RPC endpoint URL
PRIVATE_KEY	Private key of the deployer (manager) account. Never commit it.

npx hardhat compile
npx hardhat test                                   # run the contract tests
npx hardhat run scripts/deploy.js --network sepolia
npm run dev                                        # http://localhost:3000

After deploying, copy the new address from config.json into the contractAddress constant at the top of pages/index.js. The UI does not read config.json.

Screenshots

Find my ticket	Purchase
Available tickets	Ticket lookup
Resale listing	Swap
Transaction on Sepolia Etherscan

There is a recorded walkthrough in loom-video.mp4 (about 16 MB).

Limitations

• The "Return Your Ticket" card calls returnTicket, which the contract does not implement, so refunds always fail.
• Each address can hold only one ticket. The day ranges (up to ID 100000) are labels in the UI only. The deploy script creates 100 tickets.
• checkResale, getAvailableTickets and the constructor loop over every ticket, so gas cost grows with supply.
• Resale payouts use transfer and there is no reentrancy guard. This is fine for a testnet demo, but the contract has not been audited.
• Build output (.next/, artifacts/, cache/) is committed to the repo.

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Built by Abhishek Yadav