DelhiFund

A crowdfunding smart contract for ETHGlobal New Delhi 2025.

Overview

As a Solidity beginner, I built DelhiFund to explore Web3, using a crowdfunding template from Solidity by Example. I studied the code to understand Ether handling and time-based logic, customized the contract name and goal, and deployed it on Sepolia for ETHGlobal.

Deployment

• Network: Sepolia Testnet
• Contract Address: https://sepolia.etherscan.io/address/0xa37d8bf74096f0129a88728ba6c41935e552327b

Features

• Contribution: Users can send ETH to fund a campaign.
• Funding Goal: Tracks a 1 ETH target with a deadline.
• Withdraw/Refund: Owner withdraws funds if the goal is met; contributors can claim refunds if it fails.
• Security: Uses OpenZeppelin’s ReentrancyGuard to prevent attacks.

Code Breakdown

DelhiFund.sol implements a crowdfunding system:

• Constructor: Sets the owner and deadline based on a duration input (e.g., 7 days).
• Contribute: Accepts ETH, tracks contributions via a mapping, and emits a Contributed event.
• Withdraw: Allows the owner to withdraw funds post-deadline if the 1 ETH goal is met, using nonReentrant for security.
• GetRefund: Refunds contributors if the goal isn’t met, clearing their contribution.

I learned how require ensures safety, block.timestamp handles deadlines, and ReentrancyGuard prevents attacks. Deploying via Remix was straightforward.

Files

• DelhiFund.sol: Defines the crowdfunding contract.
• LICENSE: MIT License, allowing open-source use.
• .gitignore: Node.js template with artifacts/ for clean commits.
• README.md: This file, detailing my project and journey.

Source

Built using Solidity by Example’s crowdfunding template, licensed under MIT, with OpenZeppelin’s ReentrancyGuard.

Learning Journey

Building DelhiFund was a thrilling step in my Web3 journey! Studying the contract taught me about Ethereum transactions, state management, and security. Deploying to Sepolia and verifying on Etherscan felt like a big win.

Usage

• Compile and deploy DelhiFund.sol in Remix (Solidity 0.8.20) with a duration (e.g., 604800 for 7 days).
• Contribute ETH via MetaMask or Remix.
• After the deadline, the owner can withdraw if the goal is met, or contributors can claim refunds.
• Verify on Etherscan.

License

Licensed under the MIT License—see LICENSE.

Contact

Email me at rishabhgupta78470@gmail.com or find me on X @rishabh_guptaz. Excited to connect at ETHGlobal New Delhi 2025!