🚀 Flash Loan Arbitrage Bot for Polygon

This project is an institutional-grade flash loan arbitrage system specifically designed for the Polygon network. It enables capital-efficient trading without upfront funds by leveraging flash loans across multiple DEXs including QuickSwap and SushiSwap.

📋 Table of Contents

• Overview
• Architecture
• Smart Contracts
• Bot Implementation
• Installation
• Testing
• Deployment
• Configuration
• Usage
• Risk Management
• Troubleshooting
• Contributing
• License
• Disclaimer

🔍 Overview

The Flash Loan Arbitrage Bot for Polygon enables automated arbitrage opportunities across Polygon's DEX ecosystem. The system is optimized for Polygon's lower gas costs and faster block times while maintaining enterprise-grade security features.

Key Features

• Multi-DEX Arbitrage: Supports QuickSwap, SushiSwap, and other Polygon DEXs
• Real-time Monitoring: Node.js/TypeScript bot for continuous opportunity scanning
• Risk Management: Circuit breakers, daily volume limits, and asset risk configurations
• Gas Optimization: Optimized for Polygon's lower transaction costs
• Oracle Integration: Chainlink price feeds for secure price validation
• Enterprise Security: Reentrancy protection, 2-step ownership, and pausable functionality

🏗️ Architecture

graph TD
    A[Arbitrage Bot] --> B[FlashLoanPolygon Contract]
    B --> C[PriceOraclePolygon Contract]
    C --> D[QuickSwap]
    C --> E[SushiSwap]
    C --> F[Chainlink Oracle]
    B --> G[Risk Management]
    B --> H[Security Controls]

Core Components

• FlashLoanSecure.sol: (Recommended) Enhanced, secure, and production-ready flash loan contract.
• FlashLoanPolygon.sol: Polygon-optimized flash loan contract.
• PriceOraclePolygon.sol: Price oracle for multi-DEX price feeds.
• MockOracle.sol: Mock Chainlink oracle for testing.
• Arbitrage Bot: JavaScript/TypeScript implementation for monitoring and execution.
• Deployment Scripts: Scripts for Mumbai testnet and Polygon mainnet.

🔒 Security Analysis

For a detailed breakdown of security features, vulnerabilities fixed, and audit results, please refer to SECURITY_ANALYSIS.md.

📄 Smart Contracts

FlashLoanPolygon.sol

The main contract that implements flash loan functionality optimized for Polygon:

• Gas Optimized: Uses unchecked blocks and minimal storage writes
• Multi-DEX Support: Can execute arbitrage across multiple DEXs
• Risk Management: Implements circuit breakers, daily volume limits, and asset risk configurations
• Oracle Integration: Uses Chainlink oracles for price validation
• Security Features: Reentrancy protection, 2-step ownership, and pausable functionality

PriceOraclePolygon.sol

Price oracle contract that provides pricing information from multiple DEXs:

• Multi-DEX Support: Supports QuickSwap, SushiSwap, and other Polygon DEXs
• TWAP Calculations: Time-weighted average price calculations
• Chainlink Integration: Integration with Chainlink price feeds
• Arbitrage Detection: Identifies price discrepancies between DEXs

MockOracle.sol

Mock Chainlink oracle for testing purposes on Mumbai testnet.

🤖 Bot Implementation

The arbitrage bot is implemented in both JavaScript and TypeScript:

• Real-time Monitoring: Monitors new blocks for arbitrage opportunities
• Multi-DEX Scanning: Scans multiple DEXs for price discrepancies
• Profit Calculation: Calculates profitability including gas costs
• Auto-execution: Automatically executes profitable trades
• Risk Management: Stops execution when gas costs exceed potential profits

🚀 Installation

Prerequisites

• Node.js >= 16.0.0
• npm >= 7.0.0
• Hardhat >= 2.26.3

Setup

# Clone the repository
git clone <repository-url>
cd FlashLoan
Install dependencies
npm install
Navigate to bot directory and install bot dependencies
cd bot
npm install
cd ..

🧪 Testing

Unit Tests

# Run unit tests
npx hardhat test
Run security suite (Recommended)
npx hardhat test test/FlashLoanSecurity.js
Run reproduction tests (Vulnerability verification)
npx hardhat test test/Reproduction.test.js
Run specific test file
npx hardhat test test/FlashLoanPolygon.test.js

Fork Tests

# Run fork tests (requires Polygon mainnet fork)
npx hardhat test test/FlashLoanPolygon.fork.test.js

Coverage and Gas Reports

# Run coverage report
npx hardhat coverage
Run gas report
REPORT_GAS=true npx hardhat test

📦 Deployment

Mumbai Testnet

# Deploy to Mumbai testnet
npx hardhat run scripts/deploy-polygon-mumbai.js --network mumbai

Polygon Mainnet

# Deploy to Polygon mainnet
npx hardhat run scripts/deploy-polygon.js --network polygon

Verification

# Verify contracts on PolygonScan
npx hardhat verify --network polygon <contract-address> <constructor-args>

⚙️ Configuration

Environment Variables

Create a .env file in the bot directory with the following variables:

# Polygon RPC URL
POLYGONRPCURL=https://polygon-rpc.com/
Wallet private key (keep this secret!)
PRIVATEKEY=yourprivatekeyhere
Contract addresses (deployed contracts)
FLASHLOANADDRESS=yourflashloancontractaddress_here
PRICEORACLEADDRESS=yourpriceoraclecontractaddress_here
Explorer API keys for verification
POLYGONSCANAPIKEY=yourpolygonscanapikeyhere

Network Configuration

The project is configured to work with the following networks:

• Polygon Mainnet

- Chain ID: 137 - RPC URL: https://polygon-rpc.com/

• Mumbai Testnet

- Chain ID: 80001 - RPC URL: https://rpc-mumbai.maticvigil.com/

📈 Usage

1. Compile Contracts

npx hardhat compile

2. Deploy Contracts

# For Mumbai testnet
npx hardhat run scripts/deploy-polygon-mumbai.js --network mumbai
For Polygon mainnet
npx hardhat run scripts/deploy-polygon.js --network polygon

3. Run the Bot

# Navigate to bot directory
cd bot
Run the bot
npm start

4. Monitor Logs

The bot will output logs showing:

• Current gas prices
• Block processing
• Arbitrage opportunities found
• Transaction execution results

🛡️ Risk Management

Slippage Protection

The system implements slippage protection with configurable limits to prevent losses from price movements during trade execution.

Circuit Breakers

Circuit breakers automatically pause the system when abnormal conditions are detected:

• Daily volume limits
• Price deviation thresholds
• Recursion depth limits

Daily Limits

• Daily Volume Limit: 1,000,000 tokens
• Maximum Recursion Depth: 3 levels
• Asset-Specific Risk Configurations: Per-token limits and risk scores

🔧 Troubleshooting

Common Issues

• Compilation Errors

# Clean and recompile
   npx hardhat clean
   npx hardhat compile

• Network Connection Issues

- Verify RPC URLs in configuration - Check network connectivity - Ensure sufficient funds for gas

• Bot Execution Issues

- Check environment variables - Verify contract addresses - Ensure private key has sufficient funds

Debugging

# Enable verbose logging
DEBUG=flashloan:* npm start

🤝 Contributing

• Fork the repository
• Create a feature branch (git checkout -b feature/amazing-feature)
• Commit your changes (git commit -m 'Add amazing feature')
• Push to the branch (git push origin feature/amazing-feature)
• Open a Pull Request

Code Standards

• Solidity: Follow Solidity Style Guide
• JavaScript/TypeScript: ESLint configuration provided
• Testing: Minimum 95% code coverage required
• Documentation: All functions must include NatSpec comments

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

⚠️ Disclaimer

IMPORTANT: This software is provided "as is" without warranty. Flash loan arbitrage involves significant financial risks including:

• Smart Contract Risk: Potential bugs or exploits
• Market Risk: Price volatility and slippage
• Gas Risk: Network congestion and failed transactions
• Regulatory Risk: Changing legal landscape

Always perform thorough testing and risk assessment before deploying to mainnet with real funds.

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📞 Support & Contact

• 📧 Email: [singharya2209@gmail.com]
• 🐛 Issues: GitHub Issues
• 💬 Discussions: GitHub Discussions
• 📱 Twitter: [@ARYASINGHBAIS]

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