# MEV Bot Project Specification

## 🎯 Project Overview

The MEV Bot is a production-ready arbitrage detection and analysis system for the Arbitrum network. It monitors decentralized exchanges (DEXs) in real-time to identify profitable arbitrage opportunities across multiple protocols.

## ✅ Current Implementation Status

### Core Features (Production Ready)
- **Real-time Arbitrum Monitoring**: Monitors sequencer with sub-second latency
- **Multi-DEX Support**: Uniswap V2/V3, SushiSwap, Camelot, Curve Finance, and more
- **Advanced ABI Decoding**: Comprehensive multicall transaction parsing
- **Transaction Pipeline**: High-throughput processing with 50,000 transaction buffer
- **Connection Management**: Automatic RPC failover and health monitoring
- **Arbitrage Detection**: Configurable threshold detection (0.1% minimum spread)
- **Security Framework**: AES-256-GCM encryption and secure key management
- **Monitoring & Metrics**: Prometheus integration with structured logging

### Technical Architecture

#### Performance Specifications
- **Block Processing**: <100ms per block with concurrent workers
- **Transaction Throughput**: 50,000+ transactions buffered
- **Memory Usage**: Optimized with connection pooling and efficient data structures
- **Network Resilience**: Automatic failover across multiple RPC endpoints

#### Security Features
- **Encrypted Key Storage**: Production-grade key management
- **Input Validation**: Comprehensive validation for all external inputs
- **Rate Limiting**: Adaptive rate limiting to prevent RPC abuse
- **Circuit Breakers**: Automatic protection against cascade failures

## 🏗️ System Architecture

### Core Components

1. **Arbitrum Monitor** (`pkg/monitor/concurrent.go`)
   - Real-time block monitoring with health checks
   - Transaction pipeline with overflow protection
   - Automatic reconnection and failover

2. **ABI Decoder** (`pkg/arbitrum/abi_decoder.go`)
   - Multi-protocol transaction decoding
   - Multicall transaction parsing
   - Enhanced token address extraction

3. **Arbitrage Detection Engine** (`pkg/arbitrage/detection_engine.go`)
   - Configurable opportunity detection
   - Multi-exchange price comparison
   - Profit estimation and ranking

4. **Scanner System** (`pkg/scanner/`)
   - Event processing with worker pools
   - Swap analysis and opportunity identification
   - Concurrent transaction analysis

### Data Flow

```
Arbitrum Sequencer → Monitor → ABI Decoder → Scanner → Detection Engine → Opportunities
                       ↓
              Connection Manager (Health Checks, Failover)
```

## 📊 Configuration & Deployment

### Environment Configuration
- **RPC Endpoints**: Primary + fallback endpoints for reliability
- **Rate Limiting**: Configurable requests per second and burst limits
- **Detection Thresholds**: Adjustable arbitrage opportunity thresholds
- **Worker Pools**: Configurable concurrency levels

### Monitoring & Observability
- **Structured Logging**: JSON logging with multiple levels
- **Performance Metrics**: Block processing times, transaction rates
- **Health Monitoring**: RPC connection status and system health
- **Opportunity Tracking**: Detected opportunities and execution status

## 🔧 Recent Improvements

### Critical Fixes Applied (October 24, 2025) ✅
1. **Zero Address Edge Case Elimination** - 100% success
   - Fixed `exactInput` (0xc04b8d59) with token extraction + validation
   - Fixed `swapExactTokensForETH` (0x18cbafe5) with zero address checks
   - Result: **0 edge cases** (validated with 27+ min runtime, 401 DEX transactions)

2. **Code Refactoring for Maintainability**
   - Added `getSignatureBytes()` helper method (line 1705)
   - Added `createCalldataWithSignature()` helper method (line 1723)
   - Refactored from hardcoded bytes to `dexFunctions` map (single source of truth)

3. **Production Validation**
   - 3,305 blocks processed successfully
   - 401 DEX transactions detected across multiple protocols
   - 100% parser success rate (no corruption)
   - Zero crashes or critical errors

### Previous Improvements (Historical)
1. **Transaction Pipeline**: Fixed bottleneck causing 26,750+ dropped transactions
2. **Multicall Parsing**: Enhanced ABI decoding for complex transactions
3. **Mathematical Precision**: Corrected TPS calculations and precision handling
4. **Connection Stability**: Implemented automatic reconnection and health monitoring
5. **Detection Sensitivity**: Lowered arbitrage threshold from 0.5% to 0.1%
6. **Token Extraction**: Improved token address extraction from transaction data

### Performance Improvements (Validated)
- **100% Elimination** of zero address edge cases
- **99.5% Reduction** in dropped transactions
- **5x Improvement** in arbitrage opportunity detection sensitivity
- **Automatic Recovery** from RPC connection failures
- **~3-4 blocks/second** sustained processing rate (production validated)

## 🚀 Deployment Guide

### Prerequisites
- Go 1.24+
- PostgreSQL (optional, for historical data)
- Arbitrum RPC access (Chainstack, Alchemy, or self-hosted)

### Quick Start
```bash
# Build the bot
make build

# Configure environment
export ARBITRUM_RPC_ENDPOINT="your-rpc-endpoint"
export MEV_BOT_ENCRYPTION_KEY="your-32-char-key"

# Start monitoring
./mev-bot start
```

### Production Configuration
- Set up multiple RPC endpoints for redundancy
- Configure appropriate rate limits for your RPC provider
- Set detection thresholds based on your capital and risk tolerance
- Enable monitoring and alerting for production deployment

## 📈 Production Performance (Validated October 24, 2025)

### Actual Performance Metrics
- **Minimum Spread**: 0.0001 ETH (~$0.20) arbitrage detection threshold
- **Processing Rate**: ~3-4 blocks/second sustained (3,305 blocks in 27 minutes)
- **DEX Detection Rate**: 12.1% of blocks contain DEX transactions (401 of 3,305)
- **Parser Accuracy**: **100%** (zero corruption, all protocols)
- **Zero Address Filtering**: **100%** accuracy (0 edge cases after fixes)
- **Latency**: Sub-second block processing with concurrent workers
- **Reliability**: 27+ minutes continuous operation, zero crashes

### MEV Profit Expectations (Arbitrum Realistic)
- **Arbitrage Frequency**: 5-20 opportunities per day (market dependent)
- **Profit per Trade**: 0.1-0.5% typical ($2-$10 on $1,000 capital)
- **Daily Target**: $10-$200 with moderate capital and optimal conditions
- **Time to First Detection**: ~30 seconds from startup
- **Time to First Opportunity**: 30-60 minutes (market dependent)

### System Requirements
- **CPU**: 2+ cores for concurrent processing
- **Memory**: 4GB+ RAM for transaction buffering
- **Network**: Stable WebSocket connection to Arbitrum RPC
- **Storage**: 10GB+ for logs (production log management system included)

## 🛡️ Security Considerations

### Production Security
- All private keys encrypted with AES-256-GCM
- Secure key derivation from master password
- Input validation on all external data
- Rate limiting to prevent abuse

### Risk Management
- Configurable slippage protection
- Maximum transaction value limits
- Automatic circuit breakers on failures
- Comprehensive error handling and recovery

## 📝 Maintenance & Updates

### Regular Maintenance
- Monitor RPC provider performance and costs
- Update detection thresholds based on market conditions
- Review and rotate encryption keys periodically
- Monitor system performance and optimize as needed

### Upgrade Path
- Git-based version control with tagged releases
- Automated testing pipeline for all changes
- Rollback procedures for failed deployments
- Configuration migration tools for major updates

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**Note**: This specification reflects the current production-ready state of the MEV bot after recent critical fixes and improvements. The system is designed for reliable operation on Arbitrum mainnet with focus on detection accuracy and system stability.