> For the complete documentation index, see [llms.txt](https://docs.saddle.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.saddle.finance/solidity-docs/virtualswap/synthswapper.md).

# SynthSwapper

Replacement of Virtual Synths in favor of gas savings. Allows swapping synths via the Synthetix protocol or Saddle's pools. The `Bridge.sol` contract will deploy minimal clones of this contract upon initiating any cross-asset swaps.

## Functions:

* [`constructor()`](#SynthSwapper-constructor--)
* [`initialize()`](#SynthSwapper-initialize--)
* [`swapSynth(bytes32 sourceKey, uint256 synthAmount, bytes32 destKey)`](#SynthSwapper-swapSynth-bytes32-uint256-bytes32-)
* [`swapSynthToToken(contract ISwap swap, contract IERC20 tokenFrom, uint8 tokenFromIndex, uint8 tokenToIndex, uint256 tokenFromAmount, uint256 minAmount, uint256 deadline, address recipient)`](#SynthSwapper-swapSynthToToken-contract-ISwap-contract-IERC20-uint8-uint8-uint256-uint256-uint256-address-)
* [`withdraw(contract IERC20 token, address recipient, uint256 withdrawAmount, bool shouldDestroy)`](#SynthSwapper-withdraw-contract-IERC20-address-uint256-bool-)
* [`destroy()`](#SynthSwapper-destroy--)

## Function `constructor()` <a href="#synthswapper-constructor" id="synthswapper-constructor"></a>

Initializes the contract when deploying this directly. This prevents others from calling initialize() on the target contract and setting themself as the owner.

## Function `initialize()` <a href="#synthswapper-initialize" id="synthswapper-initialize"></a>

Sets the `owner` as the caller of this function

## Function `swapSynth(bytes32 sourceKey, uint256 synthAmount, bytes32 destKey) → uint256` <a href="#synthswapper-swapsynth-bytes32-uint256-bytes32" id="synthswapper-swapsynth-bytes32-uint256-bytes32"></a>

Swaps the synth to another synth via the Synthetix protocol.

### Parameters:

* `sourceKey`: currency key of the source synth
* `synthAmount`: amount of the synth to swap
* `destKey`: currency key of the destination synth

### Return Values:

* amount of the destination synth received

## Function `swapSynthToToken(contract ISwap swap, contract IERC20 tokenFrom, uint8 tokenFromIndex, uint8 tokenToIndex, uint256 tokenFromAmount, uint256 minAmount, uint256 deadline, address recipient) → contract IERC20, uint256` <a href="#synthswapper-swapsynthtotoken-contract-iswap-contract-ierc20-uint8-uint8-uint256-uint256-uint256-add" id="synthswapper-swapsynthtotoken-contract-iswap-contract-ierc20-uint8-uint8-uint256-uint256-uint256-add"></a>

Approves the given `tokenFrom` and swaps it to another token via the given `swap` pool.

### Parameters:

* `swap`: the address of a pool to swap through
* `tokenFrom`: the address of the stored synth
* `tokenFromIndex`: the index of the token to swap from
* `tokenToIndex`: the token the user wants to swap to
* `tokenFromAmount`: the amount of the token to swap
* `minAmount`: the min amount the user would like to receive, or revert.
* `deadline`: latest timestamp to accept this transaction
* `recipient`: the address of the recipient

## Function `withdraw(contract IERC20 token, address recipient, uint256 withdrawAmount, bool shouldDestroy)` <a href="#synthswapper-withdraw-contract-ierc20-address-uint256-bool" id="synthswapper-withdraw-contract-ierc20-address-uint256-bool"></a>

Withdraws the given amount of `token` to the `recipient`.

### Parameters:

* `token`: the address of the token to withdraw
* `recipient`: the address of the account to receive the token
* `withdrawAmount`: the amount of the token to withdraw
* `shouldDestroy`: whether this contract should be destroyed after this call

## Function `destroy()` <a href="#synthswapper-destroy" id="synthswapper-destroy"></a>

Destroys this contract. Only owner can call this function.