Borrow and repay

Positions in Vesu are created, managed, and closed through a single function, called manage_position, on the respective Pool's contract. We here discuss how compute your calldata to borrow and repay assets on a position.

Borrow assets

To borrow assets, use the manage_position function of the respective Pool contract with the following ModifyPositionParams(collateral_asset,debt_asset,user,collateral,debt) data:

• collateral_asset: The address of the asset that is to be supplied as collateral
• debt_asset: The address of the asset that is to be borrowed
• user: The address of the position owner (not necessarily the transaction sender)
• collateral: The amount that should be supplied as collateral encoded as a positive integer
• debt: The amount that should be borrowed encoded as a positive integer

The amounts have to follow the Amount type as explained here. To supply collateral and borrow assets, you will have to specify both the collateral and debt amount's value fields as positive numbers.

As an example, the data for a user with account address 0x1 to supply 1000 STRK as collateral and borrow 100 USDC will look like this:

ModifyPositionParams(
    0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d,
    0x053c91253bc9682c04929ca02ed00b3e423f6710d2ee7e0d5ebb06f3ecf368a8,
    0x1,
    Amount(AmountDenomination:Assets, 1000),
    Amount(AmountDenomination:Assets, 100)
)

info

Note that if user is not the sender of the transaction, user first has to delegate his position to the sender through modify_delegation.

Repay assets

To repay debt of an existing position, follow the exact same approach as explained in the "Borrow assets" section but specify only a non-zero amount in the debt field:

• collateral_asset: The address of the collateral asset of the position
• debt_asset: The address of the debt asset of the position
• user: The address of the position owner (not necessarily the transaction sender)
• collateral: A zero amount
• debt: The amount that should be repaid encoded as a negative integer

As an example, the data for a user with account address 0x1, borrowing USDC with STRK as collateral, and wanting to repay 50 USDC will look like this:

ModifyPositionParams(
    0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d,
    0x053c91253bc9682c04929ca02ed00b3e423f6710d2ee7e0d5ebb06f3ecf368a8,
    0x1,
    Amount(AmountDenomination:Assets, 0),
    Amount(AmountDenomination:Assets, -50)
)

Close position

To close a position, a user needs to repay all outstanding debt and withdraw all remaining collateral assets. However, due to the nature of per-block interest accruals, the total debt outstanding and collateral assets withdrawable are only known at the block where the transaction is included. Therefore, amounts have to be expressed in Native denomination instead.

The ModifyPositionParams data thus are computed as:

• collateral_asset: The address of the collateral asset of the position
• debt_asset: The address of the debt asset of the position
• user: The address of the position owner
• collateral: The collateral_shares owned by the position encoded as an Amount with AmountDenomination:Native and negative integer in the value field
• debt: The nominal_debt owed by the position encoded as an Amount with AmountDenomination:Native and negative integer in the value field

As an example, the data for a user with account address 0x1, borrowing USDC with STRK as collateral, and having 900 collateral_shares and 90 nominal_debt units outstanding will look like:

ModifyPositionParams(
    0x04718f5a0fc34cc1af16a1cdee98ffb20c31f5cd61d6ab07201858f4287c938d,
    0x053c91253bc9682c04929ca02ed00b3e423f6710d2ee7e0d5ebb06f3ecf368a8,
    0x1,
    Amount(AmountDenomination:Native, -900),
    Amount(AmountDenomination:Native, -90)
)