Let's Get HAI: CDP Stablecoin Borrowing Against LSTs on OP Mainnet

2026-08-26

Let's Get HAI is a CDP protocol on OP Mainnet that lets users borrow HAI: an over-collateralised, decentralised stablecoin: against LSTs and Optimism-native assets. It is inspired by Reflexer Finance and GEB, using a PI controller for autonomous interest rate adjustment. When HAI trades above $1, the system lowers the redemption price to discourage borrowing. When below $1, it raises the price to incentivise repayment. The result is a stablecoin that stabilises through market incentives rather than direct peg maintenance.

Revenue flows from stability fees paid by HAI borrowers on their collateralised debt positions, and from liquidation penalties charged on undercollateralised vaults. The system dynamically discovers all collateral types via TaxCollector.collateralList() - currently 20 types including WETH, wstETH, OP, rETH, and Beefy vault tokens. Revenue is split between the protocol treasury and supply-side participants: Stability Pool depositors collect profits through the Automated Liquidation Profit Sharing system, and Dutch-auction buyers earn collateral discounts during liquidations.

HAI's Reflexer-inspired architecture means stability fees are not event-driven: they accrue continuously through a rate multiplier applied to each CDP's debt balance. Daily fees required snapshotting the global debt multiplier at the start and end of each period rather than summing payment events. The adapter is merged as dimension-adapters #9001. All-time fees stand at $115,500 with $245 in the past seven days.

Website: letsgethai.com · Twitter: @letsgethai