flashloan-profit-calculator/README.md

A library for analyzing flashloan transactions and calculating profits

# Flashloan Profit Calculator

This tool analyzes Ethereum transaction logs to calculate the profit made from flashloan arbitrage or other DeFi operations.

## Features

- Calculate profit directly from a transaction hash
- Analyze token transfers (ERC20) from logs
- Track ETH transfers from trace data
- Fetch token metadata for proper display
- CLI interface for easy usage

## Project Structure

The codebase is organized in a modular way:

- `tokenTypes.ts` - Type definitions and constants
- `transferProcessor.ts` - Process transfers and update balances
- `profitCalculator.ts` - Calculate profit from balance changes
- `index.ts` - Main API entry points
- `cli.ts` - Command-line interface

## Setup

1. Clone this repository
2. Install dependencies:
   ```bash
   npm install
   ```
3. Create a `.env` file with:
   ```
   ALCHEMY_API_KEY=your_alchemy_api_key
   ```

## Usage

### Command Line Interface

Analyze a transaction:

```bash
npx ts-node cli.ts 0x123...abc
```

Where `0x123...abc` is the transaction hash you want to analyze.

### Programmatic Usage

Import the library:

```typescript
import { calculateProfitFromTxHash, displayProfitResults } from './index';

async function analyzeTx(txHash: string) {
  try {
    // Calculate profit
    const profit = await calculateProfitFromTxHash(txHash);
    
    // Display results
    await displayProfitResults(profit);
    
    // Or use the raw profit data
    console.log('Raw profit data:', profit);
  } catch (error) {
    console.error('Error:', error);
  }
}

// Analyze a transaction
analyzeTx('0x123...abc');
```

## How It Works

1. Fetches transaction details using Alchemy API
2. Extracts logs and traces from the transaction
3. Processes transfer logs to track token movements
4. Analyzes ETH transfers from trace data
5. Calculates profit by summing revenue and costs
6. Displays results with proper token information

## Requirements

- Node.js v14+
- TypeScript
- Alchemy API key