CovenantDefaults.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import {ReceivableNote} from "./ReceivableNote.sol";

/// @notice The desk's default risk policy, in one place.
///
///         Deploy scripts, the demo narrative and the test suite all read the curve
///         from here rather than each restating it. When those three disagree the
///         failure is silent and specific: tests assert a rate the deployed desk does
///         not actually charge.
///
///         The bands are eligibility bands, not credit ratings. `subTier` is the axis
///         an integrator sets when issuing a Cleanverse A-Pass, so it measures how
///         thoroughly a counterparty has been verified — deeper verification narrows
///         the discount, and that is the whole claim. It is not a probability of
///         default and is never presented as one.
library CovenantDefaults {
    uint8 internal constant SUBTIER_INSTITUTIONAL = 80;
    uint8 internal constant SUBTIER_ESTABLISHED = 50;
    uint8 internal constant SUBTIER_BASIC = 20;

    uint16 internal constant RATE_INSTITUTIONAL = 9_700; // 97%
    uint16 internal constant RATE_ESTABLISHED = 9_300; // 93%
    uint16 internal constant RATE_BASIC = 8_800; // 88%

    /// @notice A supplier below this has not been verified deeply enough to originate
    ///         at all — it is the floor that keeps anonymous originators out, not a
    ///         pricing input.
    uint8 internal constant MIN_ORIGINATOR_SUBTIER = 20;

    function rateBands() internal pure returns (ReceivableNote.RateBand[] memory bands) {
        bands = new ReceivableNote.RateBand[](3);
        bands[0] = ReceivableNote.RateBand({minSubTier: SUBTIER_INSTITUTIONAL, advanceRateBps: RATE_INSTITUTIONAL});
        bands[1] = ReceivableNote.RateBand({minSubTier: SUBTIER_ESTABLISHED, advanceRateBps: RATE_ESTABLISHED});
        bands[2] = ReceivableNote.RateBand({minSubTier: SUBTIER_BASIC, advanceRateBps: RATE_BASIC});
    }
}