Nuro Fi

NuroFi is the first yield-bearing collateral lending protocol on Arc. Users deposit USYC (US Yield Coin) as collateral and continue earning yield while borrowing USDC across multiple chains. Traditional lending protocols force users to choose between earning yield or using assets as collateral. NuroFi changes this by allowing USYC holders to keep their yield-bearing position active while unlocking liquidity through USDC borrowing. Your collateral works for you even while it's locked.

NuroFi uses Arc as the central liquidity hub for all USDC movements. Instead of fragmenting liquidity across multiple chains, Arc serves as the settlement layer where USDC is sourced, routed, and settled efficiently. Users can borrow USDC on any supported chain without manual bridging. Lend USYC on Arc, borrow USDC on Base.

Combined with Circle Wallets for simplified onboarding and wallet management, users interact with one unified interface while Arc handles the cross-chain routing behind the scenes. One collateral position, yield still earning, USDC available anywhere.

Nuro Fi uses Next.js and TypeScript for the frontend, providing a responsive and fast user interface. We integrated Circle Wallets to handle user authentication and wallet management, allowing users to interact with multiple chains through a single wallet experience without needing to switch networks manually. The UI displays unified lending positions across all supported chains in one dashboard.

For the backend, Nuro Fi uses Ponder as the indexing and data infrastructure. Ponder listens to on-chain events from our smart contracts across multiple chains and aggregates them into a unified API. This allows the frontend to fetch user positions, lending rates, and collateral data from all chains through a single endpoint, making the cross-chain experience feel like a single-chain app.

The smart contracts are written in Solidity and deployed on Arc and other supported EVM chains. These contracts handle core lending logic including deposits, withdrawals, collateral management, and liquidations. For cross-chain functionality, Nuro Fi integrates LayerZero's OApp contracts to enable secure message passing between chains. When a user deposits on one chain and borrows on another, LayerZero handles the cross-chain verification and state synchronization.

For price feeds, Nuro Fi uses Band Protocol as the oracle to fetch reliable, decentralized price data for collateral valuation. Band provides price feeds which is essential for accurate collateral ratio calculations and liquidation triggers across multiple chains.

The trickiest part was syncing collateral states across chains in real-time. We solved this by having Ponder index LayerZero message events and updating the frontend optimistically while waiting for cross-chain confirmation, giving users instant feedback while maintaining security.