InterestRateModel

The current InterestRateModel interface exposes three functions. Rates are mantissas scaled by 1e18 and are returned per slot, where the implementation defines a slot as a block or one second.

getBorrowRate

function getBorrowRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves,
    uint256 badDebt
) external view returns (uint256);

Returns the borrow rate per slot. Current model implementations calculate utilization from (borrows + badDebt) / (cash + borrows + badDebt - reserves) and cap utilization at 1e18.

getSupplyRate

function getSupplyRate(
    uint256 cash,
    uint256 borrows,
    uint256 reserves,
    uint256 reserveFactorMantissa,
    uint256 badDebt
) external view returns (uint256);

Returns the supplier rate per slot after applying the reserve factor. Supply-rate income is based on performing borrows; bad debt affects utilization and the denominator but is not multiplied into incomeToDistribute.

isInterestRateModel

function isInterestRateModel() external pure returns (bool);

Returns true as a compatibility marker.

The interface does not expose the clock. Current implementations inherit isTimeBased() and blocksOrSecondsPerYear() from TimeManagerV8; read those functions from the deployed model before annualizing a rate.