Decentralized Lending Platform with Zero-Knowledge Proof-Based Credit

This project is a full-stack implementation of a proposed protocol enabling decentralized lending based on zero-knowledge proof-based credit fostering more efficient virtual asset liquidity.

• in partial fulfillment of the requirements for COMP 4981 in the Department of Computer Science and Engineering, The Hong Kong University of Science and Technology;

• and in partial fulfillment of the requirements for CPEG 4901 in the Computer Engineering Program Office, The Hong Kong University of Science and Technology.

Figure 1: Screen Capture of the Loan Requests List Page of the Demo Web Application

Design Overview

---

1. Architecture Overview

The project principally follows a MERN-stack structure:

Frontend:

• Vite (frontend build tool for HMR support and faster builds)
• React Typescript

Backend:

• Express Typescript
• Node.js
• The backend express app uses nodemon for HMR support.

Database:

• MongoDB (currently hosted via Mongo Atlas for dev)
• The backend uses the mongoose Object Data Modeling (ODM) library

Python Local Script

• Python Executable

2. Codebase Structure

The frontend react app is separate from the backend express app, each having their own node package management.

Frontend:

./utils currently contains utility functions for formatting ./public should contain all the static files, like stylesheets, images etc. (e.g../public/images) The codebase uses a .env.local file for abstracting sensitive information from the source code that is published to Github.

Backend:

The codebase uses .dotenv (/.env) files for abstracting sensitive information from the source code that is published to GitHub.

Python Local Script

The Python Local Script is compiled and packaged as an executable for accessibility and convenience.

Smart Contracts

This directory contains the source code of our deployed Smart Contract on-chain.

Setup

---

1. cd into and run npm install in both the ./backend and ./frontend directories
2. Backend: create an .env file under ./backend first before running npm run dev to start the backend server

MONGO_URI = <YourBackendEndpointAPI>
PORT = <SpecifiedBackendPort>

3. Frontend: create an .env.local file under ./frontend first before running npm run dev to start the frontend server

VITE_SEPOLIA_CONTRACT_ADDRESS = '0xe789df42675449166f8fcf0a0239b05973c6b9a7' (This is public address of our deployed Smart Contract)
VITE_LOCAL_SCRIPT_HOST = <SpecifiedLocalScriptHost: Expected 5000>
VITE_BACKEND_HOST = <SpecifiedBackendHost: Must be same as in ./backend/.env>