# Vault

## Vault

* Responsible for following actions on USDs:
  * Mint USDs token
  * Redeem USDs token
  * Carry out rebase for USDs token
  * Allocate collateral to strategies
  * Withdraw collateral from strategies

## Contract documentation

[Git Source](https://github.com/Sperax/USDs-v2/blob/ff71faf9d7e40d2b2764e5e8f2acc631f31489aa/contracts/vault/VaultCore.sol)

**Inherits:** Initializable, OwnableUpgradeable, ReentrancyGuardUpgradeable

**Author:** Sperax Foundation

This contract enables users to mint and redeem USDs with allowed collaterals.

It also allocates collateral to strategies based on the Collateral Manager contract.

### **State Variables**

#### **feeVault**

```solidity
address public feeVault;

```

#### **yieldReceiver**

```solidity
address public yieldReceiver;

```

#### **collateralManager**

```solidity
address public collateralManager;

```

#### **feeCalculator**

```solidity
address public feeCalculator;

```

#### **oracle**

```solidity
address public oracle;

```

#### **rebaseManager**

```solidity
address public rebaseManager;

```

### **Functions**

#### **constructor**

```solidity
constructor();

```

#### **initialize**

```solidity
function initialize() external initializer;

```

#### **updateFeeVault**

Updates the address receiving fee.

```solidity
function updateFeeVault(address _feeVault) external onlyOwner;

```

**Parameters**

| Name       | Type    | Description                     |
| ---------- | ------- | ------------------------------- |
| \_feeVault | address | New desired SPABuyback address. |

#### **updateYieldReceiver**

Updates the address receiving yields from strategies.

```solidity
function updateYieldReceiver(address _yieldReceiver) external onlyOwner;

```

**Parameters**

| Name            | Type    | Description                         |
| --------------- | ------- | ----------------------------------- |
| \_yieldReceiver | address | New desired yield receiver address. |

#### **updateCollateralManager**

Updates the address having the configuration for collaterals.

```solidity
function updateCollateralManager(address _collateralManager) external onlyOwner;

```

**Parameters**

| Name                | Type    | Description                             |
| ------------------- | ------- | --------------------------------------- |
| \_collateralManager | address | New desired collateral manager address. |

#### **updateRebaseManager**

Updates the address having the configuration for rebases.

```solidity
function updateRebaseManager(address _rebaseManager) external onlyOwner;

```

**Parameters**

| Name            | Type    | Description                         |
| --------------- | ------- | ----------------------------------- |
| \_rebaseManager | address | New desired rebase manager address. |

#### **updateFeeCalculator**

Updates the fee calculator library.

```solidity
function updateFeeCalculator(address _feeCalculator) external onlyOwner;

```

**Parameters**

| Name            | Type    | Description                         |
| --------------- | ------- | ----------------------------------- |
| \_feeCalculator | address | New desired fee calculator address. |

#### **updateOracle**

Updates the price oracle address.

```solidity
function updateOracle(address _oracle) external onlyOwner;

```

**Parameters**

| Name     | Type    | Description                 |
| -------- | ------- | --------------------------- |
| \_oracle | address | New desired oracle address. |

#### **allocate**

Allocates `_amount` of `_collateral` to `_strategy`.

```solidity
function allocate(address _collateral, address _strategy, uint256 _amount) external nonReentrant;

```

**Parameters**

| Name         | Type    | Description                           |
| ------------ | ------- | ------------------------------------- |
| \_collateral | address | Address of the desired collateral.    |
| \_strategy   | address | Address of the desired strategy.      |
| \_amount     | uint256 | Amount of collateral to be allocated. |

#### **mint**

Mint USDs by depositing collateral.

```solidity
function mint(address _collateral, uint256 _collateralAmt, uint256 _minUSDSAmt, uint256 _deadline)
    external
    nonReentrant;

```

**Parameters**

| Name            | Type    | Description                                   |
| --------------- | ------- | --------------------------------------------- |
| \_collateral    | address | Address of the collateral.                    |
| \_collateralAmt | uint256 | Amount of collateral to mint USDs with.       |
| \_minUSDSAmt    | uint256 | Minimum expected amount of USDs to be minted. |
| \_deadline      | uint256 | Expiry time of the transaction.               |

#### **mintBySpecifyingCollateralAmt**

Mint USDs by depositing collateral (backward compatibility).

*This function is for backward compatibility.*

```solidity
function mintBySpecifyingCollateralAmt(
    address _collateral,
    uint256 _collateralAmt,
    uint256 _minUSDSAmt,
    uint256,
    uint256 _deadline
) external nonReentrant;

```

**Parameters**

| Name            | Type    | Description                                   |
| --------------- | ------- | --------------------------------------------- |
| \_collateral    | address | Address of the collateral.                    |
| \_collateralAmt | uint256 | Amount of collateral to mint USDs with.       |
| \_minUSDSAmt    | uint256 | Minimum expected amount of USDs to be minted. |
|                 | uint256 |                                               |
| \_deadline      | uint256 | Expiry time of the transaction.               |

#### **redeem**

Redeem USDs for `_collateral`.

*In case where there is not sufficient collateral available in the vault, the collateral is withdrawn from the default strategy configured for the collateral.*

```solidity
function redeem(address _collateral, uint256 _usdsAmt, uint256 _minCollAmt, uint256 _deadline) external nonReentrant;

```

**Parameters**

| Name         | Type    | Description                                           |
| ------------ | ------- | ----------------------------------------------------- |
| \_collateral | address | Address of the collateral.                            |
| \_usdsAmt    | uint256 | Amount of USDs to be redeemed.                        |
| \_minCollAmt | uint256 | Minimum expected amount of collateral to be received. |
| \_deadline   | uint256 | Expiry time of the transaction.                       |

#### **redeem**

Redeem USDs for `_collateral` from a specific strategy.

```solidity
function redeem(address _collateral, uint256 _usdsAmt, uint256 _minCollAmt, uint256 _deadline, address _strategy)
    external
    nonReentrant;

```

**Parameters**

| Name         | Type    | Description                                                 |
| ------------ | ------- | ----------------------------------------------------------- |
| \_collateral | address | Address of the collateral.                                  |
| \_usdsAmt    | uint256 | Amount of USDs to be redeemed.                              |
| \_minCollAmt | uint256 | Minimum expected amount of collateral to be received.       |
| \_deadline   | uint256 | Expiry time of the transaction.                             |
| \_strategy   | address | Address of the strategy to withdraw excess collateral from. |

#### **redeemView**

Get the expected redeem result.

```solidity
function redeemView(address _collateral, uint256 _usdsAmt)
    external
    view
    returns (
        uint256 calculatedCollateralAmt,
        uint256 usdsBurnAmt,
        uint256 feeAmt,
        uint256 vaultAmt,
        uint256 strategyAmt
    );

```

**Parameters**

| Name         | Type    | Description                    |
| ------------ | ------- | ------------------------------ |
| \_collateral | address | Desired collateral address.    |
| \_usdsAmt    | uint256 | Amount of USDs to be redeemed. |

**Returns**

| Name                    | Type    | Description                                                                  |
| ----------------------- | ------- | ---------------------------------------------------------------------------- |
| calculatedCollateralAmt | uint256 | Expected amount of collateral to be released based on the price calculation. |
| usdsBurnAmt             | uint256 | Expected amount of USDs to be burnt in the process.                          |
| feeAmt                  | uint256 | Amount of USDs collected as fee for redemption.                              |
| vaultAmt                | uint256 | Amount of collateral released from Vault.                                    |
| strategyAmt             | uint256 | Amount of collateral to withdraw from the strategy.                          |

#### **redeemView**

Get the expected redeem result from a specific strategy.

```solidity
function redeemView(address _collateral, uint256 _usdsAmt, address _strategyAddr)
    external
    view
    returns (
        uint256 calculatedCollateralAmt,
        uint256 usdsBurnAmt,
        uint256 feeAmt,
        uint256 vaultAmt,
        uint256 strategyAmt
    );

```

**Parameters**

| Name           | Type    | Description                         |
| -------------- | ------- | ----------------------------------- |
| \_collateral   | address | Desired collateral address.         |
| \_usdsAmt      | uint256 | Amount of USDs to be redeemed.      |
| \_strategyAddr | address | Address of strategy to redeem from. |

**Returns**

| Name                    | Type    | Description                                                                  |
| ----------------------- | ------- | ---------------------------------------------------------------------------- |
| calculatedCollateralAmt | uint256 | Expected amount of collateral to be released based on the price calculation. |
| usdsBurnAmt             | uint256 | Expected amount of USDs to be burnt in the process.                          |
| feeAmt                  | uint256 | Amount of USDs collected as fee for redemption.                              |
| vaultAmt                | uint256 | Amount of collateral released from Vault.                                    |
| strategyAmt             | uint256 | Amount of collateral to withdraw from the strategy.                          |

#### **rebase**

Rebase USDs to share earned yield with the USDs holders.

*If Rebase manager returns a non-zero value, it calls the rebase function on the USDs contract.*

```solidity
function rebase() public;

```

#### **mintView**

Get the expected mint result (USDs amount, fee).

```solidity
function mintView(address _collateral, uint256 _collateralAmt) public view returns (uint256, uint256);

```

**Parameters**

| Name            | Type    | Description            |
| --------------- | ------- | ---------------------- |
| \_collateral    | address | Address of collateral. |
| \_collateralAmt | uint256 | Amount of collateral.  |

**Returns**

| Name | Type    | Description                                                |
| ---- | ------- | ---------------------------------------------------------- |
|      | uint256 | Returns the expected USDs mint amount and fee for minting. |
|      | uint256 |                                                            |

#### **\_mint**

Mint USDs by depositing collateral.

*Mints USDs by locking collateral based on user input, ensuring a minimum expected minted amount is met.*

*If the minimum expected amount is not met, the transaction will revert.*

*Fee is collected, and collateral is transferred accordingly.*

*A rebase operation is triggered after minting.*

```solidity
function _mint(address _collateral, uint256 _collateralAmt, uint256 _minUSDSAmt, uint256 _deadline) private;

```

**Parameters**

| Name            | Type    | Description                                   |
| --------------- | ------- | --------------------------------------------- |
| \_collateral    | address | Address of the collateral.                    |
| \_collateralAmt | uint256 | Amount of collateral to deposit.              |
| \_minUSDSAmt    | uint256 | Minimum expected amount of USDs to be minted. |
| \_deadline      | uint256 | Deadline timestamp for executing mint.        |

#### **\_redeem**

Redeem USDs for collateral.

*Redeems USDs for collateral, ensuring a minimum expected collateral amount is met.*

*If the minimum expected collateral amount is not met, the transaction will revert.*

*Fee is collected, collateral is transferred, and a rebase operation is triggered.*

```solidity
function _redeem(
    address _collateral,
    uint256 _usdsAmt,
    uint256 _minCollateralAmt,
    uint256 _deadline,
    address _strategyAddr
) private;

```

**Parameters**

| Name               | Type    | Description                                        |
| ------------------ | ------- | -------------------------------------------------- |
| \_collateral       | address | Address of the collateral to receive.              |
| \_usdsAmt          | uint256 | Amount of USDs to redeem.                          |
| \_minCollateralAmt | uint256 | Minimum expected collateral amount to be received. |
| \_deadline         | uint256 | Deadline timestamp for executing the redemption.   |
| \_strategyAddr     | address | Address of the strategy to withdraw from.          |

#### **\_redeemView**

Get the expected redeem result.

*Calculates the expected results of a redemption, including collateral amount, fees, and strategy-specific details.*

*Ensures that the redemption is allowed for the specified collateral.*

*Calculates fees, burn amounts, and collateral amounts based on prices and conversion factors.*

*Determines if collateral needs to be withdrawn from a strategy, and if so, checks the availability of collateral in the strategy.*

```solidity
function _redeemView(address _collateral, uint256 _usdsAmt, address _strategyAddr)
    private
    view
    returns (
        uint256 calculatedCollateralAmt,
        uint256 usdsBurnAmt,
        uint256 feeAmt,
        uint256 vaultAmt,
        uint256 strategyAmt,
        IStrategy strategy
    );

```

**Parameters**

| Name           | Type    | Description                             |
| -------------- | ------- | --------------------------------------- |
| \_collateral   | address | Desired collateral address.             |
| \_usdsAmt      | uint256 | Amount of USDs to be redeemed.          |
| \_strategyAddr | address | Address of the strategy to redeem from. |

**Returns**

| Name                    | Type      | Description                                                                  |
| ----------------------- | --------- | ---------------------------------------------------------------------------- |
| calculatedCollateralAmt | uint256   | Expected amount of collateral to be released based on the price calculation. |
| usdsBurnAmt             | uint256   | Expected amount of USDs to be burnt in the process.                          |
| feeAmt                  | uint256   | Amount of USDs collected as a fee for redemption.                            |
| vaultAmt                | uint256   | Amount of collateral released from Vault.                                    |
| strategyAmt             | uint256   | Amount of collateral to withdraw from the strategy.                          |
| strategy                | IStrategy | Strategy contract to withdraw collateral from.                               |

### **Events**

#### **FeeVaultUpdated**

```solidity
event FeeVaultUpdated(address newFeeVault);

```

#### **YieldReceiverUpdated**

```solidity
event YieldReceiverUpdated(address newYieldReceiver);

```

#### **CollateralManagerUpdated**

```solidity
event CollateralManagerUpdated(address newCollateralManager);

```

#### **FeeCalculatorUpdated**

```solidity
event FeeCalculatorUpdated(address newFeeCalculator);

```

#### **RebaseManagerUpdated**

```solidity
event RebaseManagerUpdated(address newRebaseManager);

```

#### **OracleUpdated**

```solidity
event OracleUpdated(address newOracle);

```

#### **Minted**

```solidity
event Minted(
    address indexed wallet, address indexed collateralAddr, uint256 usdsAmt, uint256 collateralAmt, uint256 feeAmt
);

```

#### **Redeemed**

```solidity
event Redeemed(
    address indexed wallet, address indexed collateralAddr, uint256 usdsAmt, uint256 collateralAmt, uint256 feeAmt
);

```

#### **RebasedUSDs**

```solidity
event RebasedUSDs(uint256 rebaseAmt);

```

#### **Allocated**

```solidity
event Allocated(address indexed collateral, address indexed strategy, uint256 amount);

```

### **Errors**

#### **AllocationNotAllowed**

```solidity
error AllocationNotAllowed(address collateral, address strategy, uint256 amount);

```

#### **RedemptionPausedForCollateral**

```solidity
error RedemptionPausedForCollateral(address collateral);

```

#### **InsufficientCollateral**

```solidity
error InsufficientCollateral(address collateral, address strategy, uint256 amount, uint256 availableAmount);

```

#### **InvalidStrategy**

```solidity
error InvalidStrategy(address _collateral, address _strategyAddr);

```

#### **MintFailed**

```solidity
error MintFailed();
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.sperax.io/master/technical-documents/smart-contracts/vault.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.