Batch Router API
The Batch Router can be used to interact with Balancer onchain via state changing operations or used to query operations in an offchain context.
State-changing functions
Batch swaps
swapExactIn
function swapExactIn(
SwapPathExactAmountIn[] memory paths,
uint256 deadline,
bool wethIsEth,
bytes calldata userData
)
external
payable
returns (uint256[] memory pathAmountsOut, address[] memory tokensOut, uint256[] memory amountsOut);
Executes a swap operation involving multiple paths (steps), specifying exact input token amounts.
Parameters:
| Name | Type | Description |
|---|---|---|
| paths | SwapPathExactAmountIn[] memory | Swap paths from token in to token out, specifying exact amounts in. |
| deadline | uint256 | Deadline for the swap, after which it will revert |
| wethIsEth | bool | If true, incoming ETH will be wrapped to WETH and outgoing WETH will be unwrapped to ETH |
| userData | bytes calldata | Additional (optional) data required for the swap |
Returns:
| Name | Type | Description |
|---|---|---|
| pathAmountsOut | uint256[] memory | Calculated amounts of output tokens corresponding to the last step of each given path |
| tokensOut | address[] memory | Calculated output token addresses |
| amountsOut | uint256[] memory | Calculated amounts of output tokens, ordered by output token address |
swapExactOut
function swapExactOut(
SwapPathExactAmountOut[] memory paths,
uint256 deadline,
bool wethIsEth,
bytes calldata userData
) external payable returns (uint256[] memory pathAmountsIn, address[] memory tokensIn, uint256[] memory amountsIn);
Executes a swap operation involving multiple paths (steps), specifying exact output token amounts.
Parameters:
| Name | Type | Description |
|---|---|---|
| paths | SwapPathExactAmountOut[] memory | Swap paths from token in to token out, specifying exact amounts out. |
| deadline | uint256 | Deadline for the swap, after which it will revert |
| wethIsEth | bool | If true, incoming ETH will be wrapped to WETH and outgoing WETH will be unwrapped to ETH |
| userData | bytes calldata | Additional (optional) data required for the swap |
Returns:
| Name | Type | Description |
|---|---|---|
| pathAmountsIn | uint256[] memory | Calculated amounts of input tokens corresponding to the first step of each given path |
| tokensIn | address[] memory | Calculated input token addresses |
| amountsIn | uint256[] memory | Calculated amounts of input tokens, ordered by input token address |
Queries
querySwapExactIn
function querySwapExactIn(
SwapPathExactAmountIn[] memory paths,
bytes calldata userData
) external returns (uint256[] memory pathAmountsOut, address[] memory tokensOut, uint256[] memory amountsOut);
Queries a swap operation involving multiple paths (steps), specifying exact input token amounts.
Parameters:
| Name | Type | Description |
|---|---|---|
| paths | SwapPathExactAmountIn[] memory | Swap paths from token in to token out, specifying exact amounts in. |
| userData | bytes calldata | Additional (optional) data required for the query |
Returns:
| Name | Type | Description |
|---|---|---|
| pathAmountsOut | uint256[] memory | Calculated amounts of output tokens to be received corresponding to the last step of each given path |
| tokensOut | address[] memory | Calculated output token addresses |
| amountsOut | uint256[] memory | Calculated amounts of output tokens to be received, ordered by output token address |
querySwapExactOut
function querySwapExactOut(
SwapPathExactAmountOut[] memory paths,
bytes calldata userData
) external returns (uint256[] memory pathAmountsIn, address[] memory tokensIn, uint256[] memory amountsIn);
Queries a swap operation involving multiple paths (steps), specifying exact output token amounts.
Parameters:
| Name | Type | Description |
|---|---|---|
| paths | SwapPathExactAmountOut[] memory | Swap paths from token in to token out, specifying exact amounts out. |
| userData | bytes calldata | Additional (optional) data required for the query |
Returns:
| Name | Type | Description |
|---|---|---|
| pathAmountsIn | uint256[] memory | Calculated amounts of input tokens to be received corresponding to the last step of each given path |
| tokensIn | address[] memory | Calculated input token addresses |
| amountsIn | uint256[] memory | Calculated amounts of input tokens to be received, ordered by input token address |
Router common
See the bottom of the Router for functions common to both the Router and BatchRouter.