> For the complete documentation index, see [llms.txt](https://docs.flatqube.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.flatqube.io/integrate/smart-contracts/everwevertotip3.md).

# EverWeverToTip3

The EverWeverToTip3 defines the logic for swapping EVERs in combination with WEVERs to Tip3 tokens.

Smart contract responsible for swapping EVERs in combination with WEVERs to Tip3 tokens.

Derives following classes and interfaces: *IAcceptTokensTransferCallback, IAcceptTokensBurnCallback*.

### **`constructor`**

```
constructor() public
```

Deploy EverToTip3Gas empty wallet.

### **`buildExchangePayload`**

```
function buildExchangePayload(uint64 id, uint128 amount, address pair, uint128 expectedAmount, uint128 deployWalletValue) external pure returns (TvmCell)
```

Builds payload by filling the TVM builder instance with data derived from function params, returns builder converted to cell.

**Parameters:**

| Name              | Type    | Description                              |
| ----------------- | ------- | ---------------------------------------- |
| id                | uint64  | Operation id                             |
| amount            | uint128 | Amount of tokens to exchange             |
| pair              | address | Address of the exchange pair             |
| expectedAmount    | uint128 | Expected amount of tokens after exchange |
| deployWalletValue | uint128 | Deploy value                             |

**Return Value:**

| Type    | Description                     |
| ------- | ------------------------------- |
| TvmCell | Exchange payload in cell format |

## Callbacks

### **`onWeverWallet`**

```
function onWeverWallet(address _weverWallet) external
```

Deploys Wever wallet for the contract using `_weverWallet` address from the function params.

**Parameters:**

| Name          | Type    | Description                             |
| ------------- | ------- | --------------------------------------- |
| \_weverWallet | address | Address used to initialize wever wallet |

### **`onAcceptTokensTransfer`**

```
function onAcceptTokensTransfer(address /*tokenRoot*/, uint128 amount, address /*sender*/, address /*senderWallet*/, address user, TvmCell payload) override external
```

Callback if swap between ever and tip 3 is successful.\
Calls `onSwapEverToTip3Success` callback to the user, `SwapEverToTip3SuccessTransfer` event is emitted and tip 3 tokens are sent to a user wallet by calling `TokenWallet`’s transfer method.\
If conditions are not fulfilled swap is canceled and tokens are returned to sender’s wallet.

**Parameters:**

| Name         | Type    | Description                               |
| ------------ | ------- | ----------------------------------------- |
| tokenRoot    | address | Address of token root (optional)          |
| amount       | uint128 | Amount of tokens to transfer              |
| sender       | address | Address of tokens sender (optional)       |
| senderWallet | address | Tokens sender’s wallet address (optional) |
| user         | address | User’s address for receiving tip3 tokens  |
| payload      | TvmCell | Transfer payload data                     |

### **`onAcceptTokensBurn`**

```
function onAcceptTokensBurn( uint128 /*amount*/, address /*walletOwner*/, address /*wallet*/, address user, TvmCell payload) override external
```

If result of swap was canceled call this callback, it emits `SwapEverToTip3CancelTransfer` event and calls `onSwapEversToTip3Cancel` callback.

**Parameters:**

| Name        | Type    | Description                           |
| ----------- | ------- | ------------------------------------- |
| amount      | uint128 | Amount of tokens to burn (optional)   |
| walletOwner | address | Address of wallet owner (optional)    |
| wallet      | address | Wallet address (optional)             |
| user        | address | User’s address that canceled exchange |
| payload     | TvmCell | Burn tokens payload data              |

## Key Events

### **`SwapEverWeverToTip3Unwrap`**

```
SwapEverWeverToTip3Unwrap(address user, uint64 id);
```