# IAbstractFeeModule

[Git Source](https://gitlab.com/dfyclabs/protocol/dfyclabs-tokens/blob/85f6dfa54ce0787eb1b1345bd6726f84fe766c54/contracts/interface/abstract/IAbstractFeeModule.sol)

**Author:** DEFYCA Labs S.à.r.l

Copyright © 2023 DEFYCA Labs S.à.r.l Permission is hereby granted, free of charge, to any person obtaining a copy of the Frictionless protocol smart contracts (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL DEFYCA LABS S.à.r.l BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

## Functions

### getFeeInfo

*get the FeeInfo for a given key.*

```solidity
function getFeeInfo(bytes32 feeKey_) external view returns (FeeInfo memory);
```

**Parameters**

| Name      | Type      | Description                                           |
| --------- | --------- | ----------------------------------------------------- |
| `feeKey_` | `bytes32` | the key as generated by the function `getTokenFeeKey` |

**Returns**

| Name     | Type      | Description                                        |
| -------- | --------- | -------------------------------------------------- |
| `<none>` | `FeeInfo` | FeeInfo the fees associated with a token transfer. |

### getFeeInBps

*get the feeInBps value for a given key*

```solidity
function getFeeInBps(bytes32 tokenFeeKey_) external view returns (uint256);
```

**Parameters**

| Name           | Type      | Description                                           |
| -------------- | --------- | ----------------------------------------------------- |
| `tokenFeeKey_` | `bytes32` | the key as generated by the function `getTokenFeeKey` |

**Returns**

| Name     | Type      | Description        |
| -------- | --------- | ------------------ |
| `<none>` | `uint256` | the feeInBps value |

### getFeeRecipient

*get the feeRecipientAddr value for a given key*

```solidity
function getFeeRecipient(bytes32 tokenFeeKey_) external view returns (address);
```

**Parameters**

| Name           | Type      | Description                                           |
| -------------- | --------- | ----------------------------------------------------- |
| `tokenFeeKey_` | `bytes32` | the key as generated by the function `getTokenFeeKey` |

**Returns**

| Name     | Type      | Description                |
| -------- | --------- | -------------------------- |
| `<none>` | `address` | the feeRecipientAddr value |

### calculateFeeAmount

*Calculates the actual fee in absolute terms for a given fee in basis points.*

```solidity
function calculateFeeAmount(uint256 tokensAmount_, uint256 feeInBps_) external pure returns (uint256 feeAmount_);
```

**Parameters**

| Name            | Type      | Description                                                  |
| --------------- | --------- | ------------------------------------------------------------ |
| `tokensAmount_` | `uint256` | the amount of tokens used to determine the base calculation. |
| `feeInBps_`     | `uint256` | the fee in basis points for calculation.                     |

**Returns**

| Name         | Type      | Description                                                       |
| ------------ | --------- | ----------------------------------------------------------------- |
| `feeAmount_` | `uint256` | the actual fee in absolute terms for a given fee in basis points. |

## Events

### FrictionlessFeeSet

*Event emitted during `_setTokenFee`*

```solidity
event FrictionlessFeeSet(bytes32 indexed feeKey, FeeInfo feeInfo);
```

## Errors

### AbstractFeeModuleInvalidFeeRecipient

*error thrown if the recipient is a zero address*

```solidity
error AbstractFeeModuleInvalidFeeRecipient();
```

### AbstractFeeModuleInvalidFee

*error thrown if the feesInBps is outside the valid range*

```solidity
error AbstractFeeModuleInvalidFee(uint256 feeInBps);
```

## Structs

### FeeInfo

*Struct which defines the FeeInfo, representing the fee in basis points and the recipient of the fees on-chain.*

```solidity
struct FeeInfo {
    uint256 feeInBps;
    address feeRecipientAddr;
}
```