ArbiSim Guard

Videos

Tech Stack

Node

Python

TypeScript

Foundry / Anvil

Cloudflare Workers

MCP SDK

Neon PostgreSQL

Description

ArbiSim Guard is the only pre-flight simulation API built for AI agents on Arbitrum. Agents send a transaction or ERC-4337 UserOperation to /v1/simulate.

ArbiSim Guard spins up an ephemeral Arbitrum One fork, executes it with zero mainnet exposure, and returns a verdict in seconds: APPROVED or REJECTED, with gas cost (L1+L2), slippage %, net P&L in USD, and safety flags (revert, sandwich, stale UserOp, unsafe allowance).

If REJECTED, the agent aborts. No transaction fires. No capital lost.

Built on Arbitrum Nitro internals: brotli-zero L1 calldata compression, Stylus WASM detection, ZeroDev EntryPoint v0.6+v0.7 simulation. Exposes a native MCP tool (preflight_simulate) compatible with Vibekit, Eliza, and LangGraph out of the box.
Both simulation phases are live and verified at arbisimguard.vercel.app.

Progress During Hackathon

Week 1: Anvil fork spawner, Python analytical brain, MCP gateway, API key auth. First APPROVED/REJECTED flow live. Verified: 0.00002132 ETH gas with correct L1/L2 breakdown. Week 2: Brotli-zero L1 compression, Stylus WASM detection, ERC-4337 UserOp simulation via ZeroDev EntryPoint. Verified: expired UserOp returns REJECTED with AA20 guardrail. Week 3: Full stack deployed. Cloudflare edge auth, Vercel dashboard, real-time simulation against live Arbitrum fork. MCP tool published. Free API key live. Both phases complete. Live at arbisimguard.vercel.app

Fundraising Status

Pre-seed. Bootstrapped. Targeting Arbitrum Foundation Trailblazer 2.0 grant (~$30K USDC across three submissions: backtesting suite for Vibekit agents, preflight_simulate MCP tool, and P&L calculation components: all explicitly named as funded priorities by the Foundation). Open to ecosystem grants and protocol partnerships with GMX, Camelot, and Aave.