# PRD: Mempool Analyzer

## Summary

**One-liner**: Monitor blockchain mempools for pending transactions, gas analysis, and MEV opportunity detection
**Domain**: Cryptocurrency / Blockchain / Trading Infrastructure
**Users**: Traders, MEV Searchers, Protocol Developers, Researchers

## Problem Statement

Blockchain mempools contain pending transactions waiting to be included in blocks. Understanding mempool activity is critical for:

- Optimizing gas prices for transaction inclusion
- Detecting large pending trades before execution
- Identifying MEV (Maximal Extractable Value) opportunities
- Monitoring network congestion and fee trends
- Detecting potential front-running attacks

Currently, mempool analysis requires running full nodes, subscribing to expensive services, or manually querying complex RPC endpoints.

## User Stories

1. **As a trader**, I want to see pending large swaps in the mempool, so I can anticipate potential price impact.
   - Acceptance: Detects and displays pending DEX swaps above threshold with token pair and size

2. **As a gas optimizer**, I want to analyze current gas prices and pending tx distribution, so I can choose optimal gas for my transaction.
   - Acceptance: Shows gas price distribution, priority fee suggestions, and estimated inclusion time

3. **As a MEV searcher**, I want to identify arbitrage and sandwich opportunities in pending transactions.
   - Acceptance: Detects profitable opportunities with estimated profit and required capital

4. **As a protocol developer**, I want to monitor mempool for large pending actions on my protocol.
   - Acceptance: Filters pending txs by contract address with decoded function calls

## Functional Requirements

- **REQ-1**: Connect to Ethereum mempool via RPC/WebSocket
- **REQ-2**: Parse and decode pending transactions (transfers, swaps, approvals)
- **REQ-3**: Analyze gas price distribution and recommend optimal fees
- **REQ-4**: Detect large pending trades (configurable threshold)
- **REQ-5**: Monitor specific contract addresses for pending interactions
- **REQ-6**: Identify potential MEV opportunities (arbitrage, liquidations)
- **REQ-7**: Support multiple output formats (table, JSON, stream)

## API Integrations

| API | Purpose | Auth |
|-----|---------|------|
| Ethereum RPC | Mempool access | Alchemy, Chainstack, or Infura URL |
| Flashbots API | MEV bundle status | No auth for basic |
| DEX Subgraphs | Pool/pair data | No auth |
| Etherscan | Contract ABI | API key (free tier) |

## Success Metrics

- Real-time mempool data with < 1 second delay
- Accurate gas price recommendations (within 10% of actual)
- Detection of 90%+ large pending swaps
- Clear MEV opportunity identification with profit estimates

## Non-Goals

- Automated MEV execution (analysis only)
- Private mempool access (public mempool only)
- Transaction submission or bundling

## Supported Chains

- Ethereum (primary)
- Polygon
- Arbitrum
- Optimism
- Base
