Skip to main content

CoolerTreasuryBorrower

Git Source

Inherits: ICoolerTreasuryBorrower, Policy, PolicyEnabler

Policy which can borrow from Treasury on behalf of Cooler

  • Cooler will always represent the debt amount in 18 decimal places.
  • This logic is split out into a separate policy (rather than using TreasuryCustodian): 1/ So the Cooler debt token can be updated if required in future to another stablecoin without a redeploy of Cooler. 2/ In this case, debt is denominated in USDS but stored 'at rest' in Treasury into sUSDS for extra yield.
  • Upon an upgrade, if the actual debt token is changed (with a new deployment of this contract) to a non 18dp asset eg USDC, then borrow() and repay() will need to do the conversion.
  • This implementation borrows USDS from Treasury but deposits into sUSDS to benefit from savings yield.

State Variables​

DECIMALS​

The decimal precision of the amountInWad used in borrow and repay functions.

A constant of 18

uint8 public constant override DECIMALS = 18;

TRSRY​

Olympus V3 Treasury Module

TRSRYv1 public TRSRY;

SUSDS​

sUSDS is used within TRSRY to generate yield on idle USDS

ERC4626 public immutable SUSDS;

_USDS​

The SKY USDS token

ERC20 private immutable _USDS;

COOLER_ROLE​

bytes32 public constant COOLER_ROLE = bytes32("treasuryborrower_cooler");

Functions​

constructor​

constructor(address kernel_, address susds_) Policy(Kernel(kernel_));

configureDependencies​

Define module dependencies for this policy.

function configureDependencies() external override returns (Keycode[] memory dependencies);

Returns

NameTypeDescription
dependenciesKeycode[]- Keycode array of module dependencies.

requestPermissions​

Function called by kernel to set module function permissions.

function requestPermissions() external view override returns (Permissions[] memory requests);

Returns

NameTypeDescription
requestsPermissions[]- Array of keycodes and function selectors for requested permissions.

borrow​

Cooler borrows amount of debtToken from treasury, sent to recipient

If the debtToken is 6dp (eg USDC) then this contract needs to handle the conversion internally

function borrow(uint256 amountInWad, address recipient) external override onlyEnabled onlyRole(COOLER_ROLE);

Parameters

NameTypeDescription
amountInWaduint256The amount to borrow. Always 18 decimal places regardless of the debtToken.decimals()
recipientaddress

repay​

Repay any debtToken in this contract back to treasury.

Cooler is expected to transfer the amount to this contract prior to calling

function repay() external override onlyEnabled onlyRole(COOLER_ROLE);

writeOffDebt​

Cooler may write off debt in the case of liquidations.

This reduces the policies debt to TRSRY

function writeOffDebt(uint256 debtTokenAmount) external override onlyEnabled onlyRole(COOLER_ROLE);

setDebt​

In the case of a Cooler debt token change (eg USDS => USDC), the debt may be manually net settled from the old debt token (in the old cooler treasury borrower) to the new debt token (in the new cooler treasury borrower)

function setDebt(uint256 debtTokenAmount) external override onlyEnabled onlyAdminRole;

Parameters

NameTypeDescription
debtTokenAmountuint256The amount of debt to set in Treasury, in the debtToken.decimals() precision

debtToken​

The token (USD based stablecoin) which Cooler users borrow and repay

function debtToken() external view override returns (IERC20);

convertToDebtTokenAmount​

Convert a debt amount in wad (18dp) into the decimals of the debtToken

function convertToDebtTokenAmount(uint256 amountInWad)
    external
    view
    override
    returns (IERC20 dToken, uint256 dTokenAmount);

_reduceDebtToTreasury​

Decrease the debt to TRSRY, floored at zero

function _reduceDebtToTreasury(uint256 debtTokenAmount) private;