Flash-Arb Bot

A high-performance flash loan arbitrage bot for Arbitrum One, built with Rust and Solidity.

Project Structure

.
├── contracts/     # Solidity & Foundry tests
├── rust/          # Cargo workspace crates
│   └── executor/  # Main bot executable
├── ops/           # Production tooling
├── infra/         # Infrastructure config (systemd, etc)
├── docs/          # Documentation
├── scripts/       # Helper scripts
└── config/        # Bot configuration

Infrastructure Setup

Local Development

Prerequisites

• git (≥ 2.40)
• rustup (1.79.0)
• foundry (nightly-2025-07-30)
• node.js (20.16.0)
• just (1.27.0)
• Docker & Docker Compose

Run just env to verify your environment is properly configured.

Running the Stack

1. Set your RPC URL:

   export QUICKNODE_RPC="https://arb-mainnet.g.alchemy.com/v2/YOUR_API_KEY"

2. Start the Docker Compose stack:

   docker compose up -d --build

3. View logs:

   docker compose logs -f bot

Key Components

Anvil Fork

We use Anvil to create a local fork of Arbitrum that's always 2 blocks behind the latest block. The fork daemon automatically respawns if it crashes.

• Performance optimization: State is stored in RAM using tmpfs for 10x faster access
• Production-ready: Systemd service for automatic startup and crash recovery

Hot-Reload Configuration

The bot watches its configuration files and reloads without downtime when changes are detected:

# After editing config/bot.toml
docker compose exec bot kill -HUP 1

Verification Checklist

Component	Verification Command	Expected Result
Anvil Fork	curl -s -X POST localhost:8545 -d '{"jsonrpc":"2.0","method":"eth_blockNumber","id":1}'	Valid JSON with hex block number
tmpfs Mount	docker compose exec anvil df -h /mnt/anvil-fork	Shows tmpfs, 512MB
Bot Health	curl localhost:9000/health	{"status":"ok"}
Hot-reload	Edit config/bot.toml then docker compose exec bot kill -HUP 1	Logs show "config changed – reloading"