A fully decentralized and provably fair lottery built with Solidity, leveraging Chainlink VRF for randomness and Chainlink Automation for automated winner selection.

Built by Tolulope Malomo as part of Cyfrin Updraft Foundry Fundamentals Course

🔗 Deployed Contract (Sepolia Testnet): 0x4e642541977234f2cb84ec8f25ed78dca5879332

This project implements a trustless lottery system where participants can enter by paying an entry fee, and a random winner is automatically selected after a predefined interval — without any manual intervention or centralized control.

Key features include:

• 🎯 Provably fair randomness powered by Chainlink VRF v2.5.
• ⏱ Automated upkeep handled by Chainlink Automation, ensuring the lottery runs autonomously.
• 🧩 Modular architecture following best practices in smart contract development.
• 🧪 Comprehensive unit and integration tests for reliability and security.
• ⚙️ Deployment scripts for seamless environment setup and testing.
• 📦 Forge + Soldeer used for dependency management and reproducible builds.

├── src/
│   ├── Raffle.sol                # Main lottery contract
│   └── VRFCoordinatorMock.sol    # Mock for local testing
├── script/
│   ├── DeployRaffle.s.sol        # Deployment script
│   └── HelperConfig.s.sol        # Network configuration helper
├── test/
│   ├── RaffleUnitTest.t.sol      # Unit tests
│   └── RaffleIntegrationTest.t.sol # Integration tests
├── foundry.toml
└── README.md

All contracts were rigorously tested using Foundry’s Forge framework.

• Unit tests validate individual functions and logic.
• Integration tests ensure correct behavior with Chainlink VRF and Automation on Sepolia.

Run tests with:

forge test

Deployment is automated through Forge scripts. To deploy to Sepolia:

forge script script/DeployRaffle.s.sol --rpc-url $SEPOLIA_RPC_URL --broadcast --verify

🔍 View Contract on Etherscan 🎲 Interact directly through the Read/Write Contract tabs or your preferred wallet interface.