# Solidity API

## RelayPoolNativeGateway

Gateway contract for depositing and withdrawing native ETH to/from WETH-based RelayPools. Handles wrapping/unwrapping of ETH and provides slippage protection for all operations.

### EthTransferFailed

```
error EthTransferFailed()
```

Error when ETH transfer fails.

### OnlyWethCanSendEth

```
error OnlyWethCanSendEth()
```

Error when contract receives ETH from non-WETH address.

### RemainingEth

```
error RemainingEth()
```

Error when ETH remains in contract after operation.

### SlippageExceeded

```
error SlippageExceeded()
```

Error when slippage protection is triggered.

### WETH

```
contract IWETH WETH
```

The Wrapped ETH (WETH) contract. Used to wrap/unwrap native ETH for pool operations.

### constructor

```
constructor(address wethAddress) public
```

Initializes the gateway with the WETH contract address.

#### Parameters

| Name       | Type    | Description                                    |
|------------|---------|------------------------------------------------|
| wethAddress| address | Address of the Wrapped Native token contract     |

### deposit

```
function deposit(address pool, address receiver, uint256 minSharesOut) external payable returns (uint256 shares)
```

Deposits native ETH into a WETH-based pool. Wraps ETH to WETH, then deposits to the pool with slippage protection.

#### Parameters

| Name      | Type    | Description                                                   |
|-----------|---------|---------------------------------------------------------------|
| pool      | address | The address of the ERC4626 pool to deposit into               |
| receiver   | address | The address that will receive the pool shares                 |
| minSharesOut | uint256 | Minimum amount of shares to receive (slippage protection)       |

#### Return Values

| Name   | Type    | Description                                        |
|--------|---------|----------------------------------------------------|
| shares | uint256 | The amount of pool shares minted to the receiver    |

### mint

```
function mint(address pool, address receiver, uint256 minSharesOut) external payable returns (uint256 shares)
```

Mints pool shares by depositing native ETH. Wraps ETH, calculates shares, then mints with slippage protection.

#### Parameters

| Name      | Type    | Description                                                   |
|-----------|---------|---------------------------------------------------------------|
| pool      | address | The address of the ERC4626 pool to mint shares from          |
| receiver   | address | The address that will receive the pool shares                 |
| minSharesOut | uint256 | Minimum amount of shares to receive (slippage protection)       |

#### Return Values

### withdraw

```
function withdraw(address pool, uint256 assets, address receiver, uint256 maxSharesIn) external virtual returns (uint256 shares)
```

Withdraws a specific amount of native ETH from a WETH-based pool. Withdraws WETH from pool, unwraps to ETH, with slippage protection.

#### Parameters

| Name      | Type    | Description                                                   |
|-----------|---------|---------------------------------------------------------------|
| pool      | address | The address of the ERC4626 pool to withdraw from             |
| assets    | uint256 | Amount of native ETH to withdraw                              |
| receiver  | address | The address that will receive the native ETH                 |
| maxSharesIn | uint256 | Maximum amount of shares to burn (slippage protection)       |

#### Return Values

| Name   | Type    | Description                                        |
|--------|---------|----------------------------------------------------|
| shares | uint256 | The amount of pool shares burned                     |

### redeem

```
function redeem(address pool, uint256 shares, address receiver, uint256 minAssetsOut) external virtual returns (uint256 assets)
```

Redeems pool shares for native ETH. Redeems shares for WETH, unwraps to ETH, with slippage protection.

#### Parameters

| Name      | Type    | Description                                                   |
|-----------|---------|---------------------------------------------------------------|
| pool      | address | The address of the ERC4626 pool to redeem from               |
| shares    | uint256 | Amount of pool shares to redeem                               |
| receiver  | address | The address that will receive the native ETH                 |
| minAssetsOut | uint256 | Minimum amount of ETH to receive (slippage protection)       |

#### Return Values

| Name   | Type    | Description                                        |
|--------|---------|----------------------------------------------------|
| assets | uint256 | The amount of native ETH sent to receiver           |

### safeTransferETH

```
function safeTransferETH(address to, uint256 value) internal
```

Safely transfers ETH to an address. Reverts if the ETH transfer fails.

#### Parameters

| Name  | Type    | Description                                      |
|-------|---------|--------------------------------------------------|
| to    | address | Recipient of the ETH transfer                     |
| value | uint256 | Amount of ETH to transfer                         |

### receive

```
receive() external payable
```

Receives ETH only from WETH contract. Required for WETH unwrapping operations.