💸 Decentralized Lending Application

A decentralized finance (DeFi) lending app built with Solidity, React.js, and JavaScript.
Users can deposit tokens into ERC-4626 vaults, borrow against collateral, and repay loans — with smart contract-enforced time-based liquidations (backend fully implemented, frontend coming soon).

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🎥 Demo Video

Watch a quick demo of the lending app in action:

Click the image to watch the video.

🌐 Live Demo & Faucet

Try the app live at:
👉 https://lendingapp.on-fleek.app/

The website includes a token faucet allowing you to mint test tokens and interact with the vaults without needing any external tokens. Perfect for testing deposits, loans, and repayments in a risk-free environment.

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📝 How to Use the App

1. Get test tokens
   Use the built-in faucet on the website to mint tokens for both Vault A and Vault B.

2. Deposit Tokens into Vault A
   Earn interest by lending tokens to the pool.

3. Borrow Tokens Using Vault B Collateral
   Lock your collateral tokens in Vault B and borrow tokens against them.

4. Repay Loan Before Expiry
   Repay your loan any time before expiry to unlock collateral and avoid liquidation.

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⚙️ Features

• 🏦 Dual ERC-4626 Vaults

  • Vault A: Lending vault for deposits and loan issuance
  • Vault B: Collateral vault securing borrowers’ assets

• 🎮 Vault Controller Contract
  Manages user lock states and performs loan liquidations upon expiry

• 🪙 Two ERC-20 Test Tokens
  Available from faucet to simulate real-world lending scenarios

• 🧨 On-Chain Time-Based Loan Liquidation
  Loans are liquidated automatically when overdue

• 🖥 Frontend
  React.js with Redux for smooth user experience and state management

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⚠️ Loan Liquidation Process

Loans have a predefined duration. The system enforces liquidation automatically through the following steps:

1. Loan Issuance
   When a borrower takes a loan, their collateral is locked in Vault B and the loan start timestamp is recorded.

2. Loan Monitoring
   The Vault Controller tracks loan timestamps and checks if the loan has expired.

3. Time-Based Liquidation
   If a loan is not repaid before the expiry:

   • The borrower’s shares in Vault B are burned.
   • Collateral tokens are transferred from Vault B to the Vault Controller contract.
   • The borrower’s loan and collateral are effectively liquidated to protect lenders.

4. Repayment Before Expiry
   Borrowers can repay their loans at any time before expiry to unlock their collateral and avoid liquidation.

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⚠️ Note on Frontend Liquidation Support

The time-based liquidation logic is fully implemented and enforced on-chain via smart contracts.
However, the frontend currently does not provide a UI for manual or automatic liquidation actions. This feature will be integrated in a future update to improve user experience and transparency.

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🚀 Quick Start Guide (For Local Development)

Prerequisites

• Node.js (v16 or above recommended)
• npm or yarn
• Hardhat
• metamask account https://metamask.io/

Steps

1. Install dependencies
   npm install

2. Run smart contract tests npx hardhat test

3 Start local blockchain npx hardhat node

4 Deploy contracts npx hardhat run scripts/deploy.js --network localhost

5 Update config.json Add deployed contract addresses to the config file for the frontend to connect properly.

6 Start frontend npm run start

🛠️ Project Structure /contracts — Solidity contracts for vaults, tokens, and controllers

/scripts — Deployment and utility scripts

/test — Hardhat tests ensuring contract correctness

/frontend — React app with Redux state management

🤝 Contributing Contributions, issues, and feature requests are welcome! Feel free to open an issue or submit a pull request.

📄 License This project is licensed under the MIT License.