> For the complete documentation index, see [llms.txt](https://docs.alkemi.network/earn-contracts/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.alkemi.network/earn-contracts/docs/alkemiratemodel.md).

# Earn Interest Rate Model (AlkemiRateModel.sol)

View Source: [contracts/AlkemiRateModel.sol](https://app.gitbook.com/s/-MQ0mmOovvt0G2zyJIgA/contracts/AlkemiRateModel.sol)

**↗ Extends:** [**Exponential**](https://app.gitbook.com/s/-MQ0mmOovvt0G2zyJIgA/docs/Exponential.md)

See Model here

**Enums**

#### IRError

```javascript
enum IRError {
 NO_ERROR,
 FAILED_TO_ADD_CASH_PLUS_BORROWS,
 FAILED_TO_GET_EXP,
 FAILED_TO_MUL_PRODUCT_TIMES_BORROW_RATE
}
```

### Contract Members

**Constants & Variables**

```javascript
//public members
uint256 public blocksPerYear;
address public owner;
address public newOwner;
string public contractName;

//private members
uint8 private hundred;

//internal members
struct Exponential.Exp internal SpreadLow;
struct Exponential.Exp internal BreakPointLow;
struct Exponential.Exp internal ReserveLow;
struct Exponential.Exp internal ReserveMid;
struct Exponential.Exp internal SpreadMid;
struct Exponential.Exp internal BreakPointHigh;
struct Exponential.Exp internal ReserveHigh;
struct Exponential.Exp internal SpreadHigh;
struct Exponential.Exp internal MinRateActual;
struct Exponential.Exp internal HealthyMinURActual;
struct Exponential.Exp internal HealthyMinRateActual;
struct Exponential.Exp internal MaxRateActual;
struct Exponential.Exp internal HealthyMaxURActual;
struct Exponential.Exp internal HealthyMaxRateActual;
```

**Events**

```javascript
event OwnerUpdate(address indexed owner, address indexed newOwner);
event blocksPerYearUpdated(uint256  oldBlocksPerYear, uint256  newBlocksPerYear);
```

### Modifiers

* onlyOwner

#### onlyOwner

```javascript
modifier onlyOwner() internal
```

**Arguments**

| Name | Type | Description |
| ---- | ---- | ----------- |

### Functions

* changeRates(string \_contractName, uint256 MinRate, uint256 HealthyMinUR, uint256 HealthyMinRate, uint256 HealthyMaxUR, uint256 HealthyMaxRate, uint256 MaxRate)
* changeBlocksPerYear(uint256 \_blocksPerYear)
* transferOwnership(address newOwner\_)
* acceptOwnership()
* getUtilizationRate(uint256 cash, uint256 borrows)
* getUtilizationAndAnnualBorrowRate(uint256 cash, uint256 borrows)
* getSupplyRate(address \_asset, uint256 cash, uint256 borrows)
* getBorrowRate(address asset, uint256 cash, uint256 borrows)

#### changeRates

```javascript
function changeRates(string _contractName, uint256 MinRate, uint256 HealthyMinUR, uint256 HealthyMinRate, uint256 HealthyMaxUR, uint256 HealthyMaxRate, uint256 MaxRate) public nonpayable onlyOwner
```

**Arguments**

| Name           | Type    | Description |
| -------------- | ------- | ----------- |
| \_contractName | string  |             |
| MinRate        | uint256 |             |
| HealthyMinUR   | uint256 |             |
| HealthyMinRate | uint256 |             |
| HealthyMaxUR   | uint256 |             |
| HealthyMaxRate | uint256 |             |
| MaxRate        | uint256 |             |

#### changeBlocksPerYear

```javascript
function changeBlocksPerYear(uint256 _blocksPerYear) external nonpayable onlyOwner
```

**Arguments**

| Name            | Type    | Description |
| --------------- | ------- | ----------- |
| \_blocksPerYear | uint256 |             |

#### transferOwnership

```javascript
function transferOwnership(address newOwner_) external nonpayable onlyOwner
```

**Arguments**

| Name       | Type    | Description |
| ---------- | ------- | ----------- |
| newOwner\_ | address |             |

#### acceptOwnership

```javascript
function acceptOwnership() external nonpayable
```

**Arguments**

| Name | Type | Description |
| ---- | ---- | ----------- |

#### getUtilizationRate

```javascript
function getUtilizationRate(uint256 cash, uint256 borrows) internal view
returns(enum AlkemiRateModel.IRError, struct Exponential.Exp)
```

**Arguments**

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| cash    | uint256 |             |
| borrows | uint256 |             |

#### getUtilizationAndAnnualBorrowRate

```javascript
function getUtilizationAndAnnualBorrowRate(uint256 cash, uint256 borrows) internal view
returns(enum AlkemiRateModel.IRError, struct Exponential.Exp, struct Exponential.Exp)
```

**Arguments**

| Name    | Type    | Description |
| ------- | ------- | ----------- |
| cash    | uint256 |             |
| borrows | uint256 |             |

#### getSupplyRate

Gets the current supply interest rate based on the given asset, total cash and total borrows

```javascript
function getSupplyRate(address _asset, uint256 cash, uint256 borrows) public view
returns(uint256, uint256)
```

**Returns**

Success or failure and the supply interest rate per block scaled by 1e18

**Arguments**

| Name    | Type    | Description                                  |
| ------- | ------- | -------------------------------------------- |
| \_asset | address | The asset to get the interest rate of        |
| cash    | uint256 | The total cash of the asset in the market    |
| borrows | uint256 | The total borrows of the asset in the market |

#### getBorrowRate

Gets the current borrow interest rate based on the given asset, total cash and total borrows

```javascript
function getBorrowRate(address asset, uint256 cash, uint256 borrows) public view
returns(uint256, uint256)
```

**Returns**

Success or failure and the borrow interest rate per block scaled by 1e18

**Arguments**

| Name    | Type    | Description                                  |
| ------- | ------- | -------------------------------------------- |
| asset   | address | The asset to get the interest rate of        |
| cash    | uint256 | The total cash of the asset in the market    |
| borrows | uint256 | The total borrows of the asset in the market |