NitroBridge Vault
Revolving credit line with instant cross-chain margin refills via state channels and privacy hooks
Project Description
NitroBridge Vault is a unified DeFi terminal built on Arc Testnet that combines five core capabilities into one interface:
(1) A chain-abstracted USDC credit system where users deposit, borrow, and manage credit lines via the ArcCreditTerminal smart contract
(2) An autonomous LLM-powered risk agent that monitors credit utilization in real time and executes on-chain margin top-ups when thresholds are breached — no human in the loop
(3) Instant gasless off-chain payments through Yellow Network's Nitrolite SDK using EIP-712 authenticated state channels with sub-100ms settlement
(4) Native cross-chain USDC bridging between Ethereum Sepolia and Arc Testnet via Circle's CCTP protocol — real burn-and-mint, no wrapped tokens
(5) MEV-protected token swaps using a custom Uniswap v4 Hook that enforces a commit-reveal scheme before executing swaps on the Sepolia PoolManager, preventing front-running by hiding trade intent until execution. All integrations use real deployed contracts and live services.
How it's Made
The frontend is a Next.js 14 app using Wagmi v2 and Viem for wallet interactions, with TailwindCSS for styling. We use Wagmi's useWalletClient and useSwitchChain hooks to handle multi-chain switching between Arc Testnet (5042002) and Ethereum Sepolia (11155111).
The AI agent is a Next.js API route that calls OpenRouter's LLM with structured JSON output — it receives credit utilization data, decides whether to top up, and the frontend executes the agentTopUp() contract call.
For Yellow Network, we integrated the @aspect-build/nitrolite-sdk with WebSocket connections to the ClearNode sandbox, handling EIP-712 authentication, session creation, and real-time state channel transfers.
Circle CCTP integration uses the TokenMessenger contract for depositForBurn on Sepolia and MessageTransmitter for receiveMessage on Arc.
The Uniswap v4 MEV Shield uses a custom AntiSniperHook deployed alongside the Sepolia PoolManager (0xE03A1074c86CFeDd5C142C4F04F1a1536e203543) — it enforces commit-reveal by checking hookData flags during beforeSwap.
Smart contracts are written in Solidity with Foundry and deployed on Arc Testnet. One notably hacky thing: we pipe the LLM's JSON decision directly into an on-chain transaction, making the agent truly autonomous — the AI decides, the blockchain executes.
