Donation Smart Contract

A full-stack Ethereum dApp that allows users to donate ETH with a minimum donation enforced in USD using Chainlink Price Feeds. Includes a simple HTML/JavaScript frontend built with Viem for wallet interaction.

📜 Overview

This project enables:

• A Solidity smart contract (FundMe.sol) to collect ETH donations.

• Chainlink Oracle integration to enforce a minimum $5 USD donation.

• A frontend interface (frontend/) where users can:

• Connect MetaMask

• Send donations

• Check contract balance

• Withdraw funds (owner only)

• View how much ETH each address has donated

🧱 Smart Contract

FundMe.sol

• Users call fund() to donate ETH.

• Uses Chainlink Price Feed to ensure the donation is worth at least $5 USD.

• Tracks each donor's address and their total donations.

• withdraw() function restricted to contract owner.

PriceConvertor.sol

• A Solidity library used to:

• Fetch live ETH/USD price via Chainlink Oracle

• Convert ETH to USD

• Enforce the minimum funding requirement

🖼️ Frontend (frontend/)

Built with:

• HTML + Vanilla JavaScript

• Viem for smart contract interaction

• MetaMask integration

• Custom Chain setup (e.g., Sepolia or Anvil local chain)

Features:

• 🔌 Connect MetaMask wallet

• 💸 Donate ETH

• 💰 Check contract balance

• 🧾 View individual donation amount

• 🧑‍⚖️ Owner-only fund withdrawal

File Structure

Donation-Solidity-Smart-Contract/ ├── contracts/ │ ├── FundMe.sol # Donation smart contract │ └── PriceConvertor.sol # Library for ETH/USD price conversion │ ├── frontend/ │ ├── index.html # Frontend UI │ ├── index-js.js # JavaScript logic with Viem │ └── constants-js.js # ABI and contract address │ ├── scripts/ # (Optional) Deployment scripts ├── test/ # (Optional) Contract tests ├── README.md └── package.json # Project dependencies

🔧 Tech Stack

Solidity (Smart Contract)

Chainlink Oracles (Price Feeds)

Viem (Smart contract interaction in frontend)

MetaMask (Wallet connection)

Anvil / Sepolia (Local or testnet network)

HTML + JS (Frontend interface)

🚀 Getting Started

Clone the repo

git clone https://github.com/yourusername/Donation-Solidity-Smart-Contract cd Donation-Solidity-Smart-Contract Install a local dev server (for frontend testing)

npm install -g http-server cd frontend http-server Open in browser

Visit: http://localhost:8080

Connect MetaMask (select Sepolia or Anvil, based on contract)

🧪 Testing

Test contracts via Remix or Hardhat/Foundry.

Interact with frontend via your browser and MetaMask.

For local testing: use Anvil and import local accounts into MetaMask.

🙋 FAQ

Q: Why is my withdraw() not working? A: Ensure you're calling from the contract owner's address, and you're on the correct network (Sepolia/Anvil).

Q: Viem throws a no chain provided error? A: Pass chain: sepolia or your local anvil chain in the client constructor.

🏁 Final Note

This repo provides a simple but complete example of building a smart contract with a functional frontend using modern tooling like Viem and Chainlink. Ideal for learning and hackathon-ready projects!