Pre-flight simulation layer for Arbitrum AI agents - validate every transaction in an ephemeral fork before it touches mainnet.
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.