V2Router02

V2Router02 is used as a intermediate contract to interact with liquidity pools, or the lower level V2Pair contract. The contract can be used to swap, add liquidity, withdraw liquidity. The contract also contains many variations of these three tasks that can be used for each unique situation like using native gas tokens (i.e. ETH), and Fee-On-Transfer tokens with a tax when transfers happen.

The full contract can be found here.

Read-Only Functions​

factory​

function factory() external pure returns (address);

Returns factory address.

WETH​

function WETH() external pure returns (address);

Returns the canonical WETH address on the Ethereum mainnet, or the canonical native wrapped address for the network the contracts are deployed on.

quote​

See quote.

getAmountOut​

See getAmountOut.

getAmountIn​

See getAmountIn.

getAmountsOut​

function getAmountsOut(uint amountIn, address[] memory path) public view returns (uint[] memory amounts);

See getAmountsOut.

getAmountsIn​

function getAmountsIn(uint amountOut, address[] memory path) public view returns (uint[] memory amounts);

See getAmountsIn.

State-Changing Functions​

addLiquidity​

function addLiquidity(
  address tokenA,
  address tokenB,
  uint amountADesired,
  uint amountBDesired,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);

Adds liquidity to an ERC-20⇄ERC-20 pool.

• To cover all possible scenarios, msg.sender should have already given the router an allowance of at least amountADesired/amountBDesired on tokenA/tokenB.

• Always adds assets at the ideal ratio, according to the price when the transaction is executed.

• If a pool for the passed tokens does not exists, one is created automatically, and exactly amountADesired/amountBDesired tokens are added.

• amountAMin and amountBMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
tokenA	address	address for one of the tokens in the pair
tokenB	address	address for the other token in the pair
amountADesired	uint	amount of tokenA to add as liquidity if the B/A price is <= amountBDesired/amountADesired (A depreciates)
amountBDesired	uint	amount of tokenB to add as liquidity if the A/B price is <= amountADesired/amountBDesired (B depreciates)
amountAMin	uint	bounds the extent to which the B/A price can go up before the transaction reverts. Must be <= amountADesired
amountBMin	uint	bounds the extent to which the A/B price can go up before the transaction reverts. Must be <= amountBDesired
to	address	recipient of the liquidity tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amountA	uint	amount of tokenA added to the pair
amountB	uint	amount of tokenB added to the pair
liquidity	uint	amount of liquidity tokens minted

addLiquidityETH​

function addLiquidityETH(
  address token,
  uint amountTokenDesired,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);

Adds liquidity to an ERC-20⇄WETH pool with ETH.

• To cover all possible scenarios, msg.sender should have already given the router an allowance of at least amountTokenDesired on token.

• Always adds assets at the ideal ratio, according to the price when the transaction is executed.

• msg.value is treated as a amountETHDesired.

• Leftover ETH, if any, is returned to msg.sender.

• If a pool for the passed token and WETH does not exists, one is created automatically, and exactly amountTokenDesired/msg.value tokens are added.

• amountTokenMin and amountETHMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
token	address	other token besides WETH in the pair
amountTokenDesired	uint	amount of token to add as liquidity if the WETH/token price is <= msg.value/amountTokenDesired (token depreciates)
amountTokenMin	uint	amount of ETH to add as liquidity if the token/WETH price is <= amountTokenDesired/msg.value (WETH depreciates)
amountETHMin	uint	bounds the extent to which the WETH/token price can go up before the transaction reverts. Must be <= amountTokenDesire
to	address	recipient of the liquidity tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amountToken	uint	amount of token sent to the pair
amountETH	uint	amount of ETH converted to WETH and sent to the pool
liquidity	uint	amount of liquidity tokens minted

removeLiquidity​

function removeLiquidity(
  address tokenA,
  address tokenB,
  uint liquidity,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline
) external returns (uint amountA, uint amountB);

Removes liquidity from an ERC-20⇄ERC-20 pool.

• msg.sender should have already given the router an allowance of at least liquidity on the pool.

• amountAMin and amountBMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
tokenA	address	address for one of the tokens in the pair
tokenB	address	address for the other token in the pair
liquidity	uint	amount of liquidity tokens to remove or burn
amountAMin	uint	minimum amount of tokenA that must be received for the transaction not to revert
amountBMin	uint	minimum amount of tokenB that must be received for the transaction not to revert
to	address	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amountA	uint	amount of tokenA received
amountB	uint	amount of tokenB received

removeLiquidityETH​

function removeLiquidityETH(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external returns (uint amountToken, uint amountETH);

Removes liquidity from an ERC-20⇄WETH pool and receive ETH.

• msg.sender should have already given the router an allowance of at least liquidity on the pool.

• amountTokenMin and amountETHMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
token	address	other token besides ETH in the pair
liquidity	uint	amount of liquidity tokens to remove or burn
amountTokenMin	uint	minimum amount of token that must be received for the transaction not to revert
amountETHMin	uint	minimum amount of ETH that must be received for the transaction not to revert
to	uint	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amountToken	uint	amount of token received
amountETH	uint	amount of ETH received

removeLiquidityWithPermit​

function removeLiquidityWithPermit(
  address tokenA,
  address tokenB,
  uint liquidity,
  uint amountAMin,
  uint amountBMin,
  address to,
  uint deadline,
  bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountA, uint amountB);

Removes liquidity from an ERC-20⇄ERC-20 pool without pre-approval.

• amountAMin and amountBMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
tokenA	address	address for one of the tokens in the pair
tokenB	address	address for the other token in the pair
liquidity	uint	amount of liquidity tokens to remove
amountAMin	uint	minimum amount of tokenA that must be received for the transaction not to revert
amountBMin	uint	minimum amount of tokenB that must be received for the transaction not to revert
to	address	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert
approveMax	bool	whether or not the approval amount in the signature is for liquidity or uint(-1)
v	uint8	v component of the permit signature
r	bytes32	r component of the permit signature
s	bytes32	s component of the permit signature

Returns​

Name	Type	Description
amountA	uint	amount of tokenA received
amountB	uint	amount of tokenB received

removeLiquidityETHWithPermit​

function removeLiquidityETHWithPermit(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline,
  bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountToken, uint amountETH);

Removes liquidity from an ERC-20⇄WETTH pool and receive ETH without pre-approval.

• amountAMin and amountBMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
token	address	other token besides WETH in the pair
liquidity	uint	amount of liquidity tokens to remove
amountTokenMin	uint	minimum amount of token that must be received for the transaction not to revert
amountETHMin	uint	minimum amount of ETH that must be received for the transaction not to revert
to	address	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert
approveMax	bool	whether or not the approval amount in the signature is for liquidity or uint(-1)
v	uint8	v component of the permit signature
r	bytes32	r component of the permit signature
s	bytes32	s component of the permit signature

Returns​

Name	Type	Description
amountToken	uint	amount of token received
amountETH	uint	amount of ETH received

removeLiquidityETHSupportingFeeOnTransferTokens​

function removeLiquidityETHSupportingFeeOnTransferTokens(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline
) external returns (uint amountETH);

Identical to removeLiquidityETH, but succeeds for tokens that take a fee on transfer.

Parameters​

Name	Type	Description
token	address	other token besides WETH in the pair
liquidity	uint	amount of liquidity tokens to remove
amountTokenMin	uint	minimum amount of token that must be received for the transaction not to revert
amountETHMin	uint	minimum amount of ETH that must be received for the transaction not to revert
to	address	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amountETH	uint	amount of ETH received

removeLiquidityETHWithPermitSupportingFeeOnTransferTokens​

function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
  address token,
  uint liquidity,
  uint amountTokenMin,
  uint amountETHMin,
  address to,
  uint deadline,
  bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountETH);

Identical to removeLiquidityETHWithPermit, but succeeds for tokens that take a fee on transfer.

Parameters​

Name	Type	Description
token	address	other token besides WETH in the pair
liquidity	uint	the amount of liquidity tokens to remove
amountTokenMin	uint	minimum amount of token that must be received for the transaction not to revert
amountETHMin	uint	minimum amount of ETH that must be received for the transaction not to revert
to	address	recipient of the underlying assets
deadline	uint	unix timestamp after which the transaction will revert
approveMax	bool	whether or not the approval amount in the signature is for liquidity or uint(-1)
v	uint8	v component of the permit signature
r	bytes32	r component of the permit signature
s	bytes32	s component of the permit signature

Returns​

Name	Type	Description
amountETH	uint	The amount of ETH received.

swapExactTokensForTokens​

function swapExactTokensForTokens(
  uint amountIn,
  uint amountOutMin,
  address[] calldata path,
  address to,
  uint deadline
) external returns (uint[] memory amounts);

Swaps an exact amount of input tokens for as many output tokens as possible, along the route determined by the path. The first element of path is the input token, the last is the output token, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• msg.sender should have already given the router an allowance of at least amountIn on the input token.

• amountOutMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
amountIn	uint	amount of input tokens to send
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	The input token amount and all subsequent output token amounts.

swapTokensForExactTokens​

function swapTokensForExactTokens(
  uint amountOut,
  uint amountInMax,
  address[] calldata path,
  address to,
  uint deadline
) external returns (uint[] memory amounts);

Receive an exact amount of output tokens for as few input tokens as possible, along the route determined by the path. The first element of path is the input token, the last is the output token, and any intermediate elements represent intermediate tokens to trade through (if, for example, a direct pair does not exist).

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• msg.sender should have already given the router an allowance of at least amountIn on the input token.

• amountInMax can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
amountOut	uint	amount of output tokens to receive
amountInMax	uint	maximum amount of input tokens that can be required before the transaction reverts
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	input token amount and all subsequent output token amounts

swapExactETHForTokens​

function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
  external
  payable
  returns (uint[] memory amounts);

Swaps an exact amount of ETH for as many output tokens as possible, along the route determined by the path. The first element of path must be WETH, the last is the output token, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• amountOutMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
msg.value (amountIn)	uint	amount of ETH to send
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	input token amount and all subsequent output token amounts

swapTokensForExactETH​

function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
  external
  returns (uint[] memory amounts);

Receive an exact amount of ETH for as few input tokens as possible, along the route determined by the path. The first element of path is the input token, the last must be WETH, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

• msg.sender should have already given the router an allowance of at least amountInMax on the input token.

• If the to address is a smart contract, it must have the ability to receive ETH.

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• amountInMax can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
amountOut	uint	amount of ETH to receive
amountInMax	uint	maximum amount of input tokens that can be required before the transaction reverts
path	address[] calldata	array of token addresses
to	address	recipient of ETH
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	input token amount and all subsequent output token amounts

swapExactTokensForETH​

function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
  external
  returns (uint[] memory amounts);

Swaps an exact amount of tokens for as much ETH as possible, along the route determined by the path. The first element of path is the input token, the last must be WETH, and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

• If the to address is a smart contract, it must have the ability to receive ETH.

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• amountOutMin can be used for slippage protection.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
amountIn	uint	amount of input tokens to send
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert
path	address[] calldata	array of token addresses
to	address	recipient of the ETH
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	input token amount and all subsequent output token amounts

swapETHForExactTokens​

function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
  external
  payable
  returns (uint[] memory amounts);

Receive an exact amount of tokens for as little ETH as possible, along the route determined by the path. The first element of path must be WETH, the last is the output token and any intermediate elements represent intermediate pairs to trade through (if, for example, a direct pair does not exist).

• Leftover ETH, if any, is returned to msg.sender.

• path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.

• deadline is used to set a time restriction on how long it can take for the tx to be executed.

Parameters​

Name	Type	Description
amountOut	uint	amount of tokens to receive
msg.value (amountInMax)	uint	maximum amount of ETH that can be required before the transaction reverts
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

Returns​

Name	Type	Description
amounts	uint[] memory	input token amount and all subsequent output token amounts

swapExactTokensForTokensSupportingFeeOnTransferTokens​

function swapExactTokensForTokensSupportingFeeOnTransferTokens(
  uint amountIn,
  uint amountOutMin,
  address[] calldata path,
  address to,
  uint deadline
) external;

Identical to swapExactTokensForTokens, but succeeds for tokens that take a fee on transfer.

• msg.sender should have already given the router an allowance of at least amountIn on the input token.

Parameters​

Name	Type	Description
amountIn	uint	amount of input tokens to send.
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

swapExactETHForTokensSupportingFeeOnTransferTokens​

function swapExactETHForTokensSupportingFeeOnTransferTokens(
  uint amountOutMin,
  address[] calldata path,
  address to,
  uint deadline
) external payable;

Identical to swapExactETHForTokens, but succeeds for tokens that take a fee on transfer.

Parameters​

Name	Type	Description
msg.value (amountIn)	uint	amount of ETH to send
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert
path	address[] calldata	array of token addresses
to	address	recipient of the output tokens
deadline	uint	unix timestamp after which the transaction will revert

swapExactTokensForETHSupportingFeeOnTransferTokens​

function swapExactTokensForETHSupportingFeeOnTransferTokens(
  uint amountIn,
  uint amountOutMin,
  address[] calldata path,
  address to,
  uint deadline
) external;

Identical to swapExactTokensForETH, but succeeds for tokens that take a fee on transfer.

• If the to address is a smart contract, it must have the ability to receive ETH.

Parameters​

Name	Type	Description
amountIn	uint	amount of input tokens to send
amountOutMin	uint	minimum amount of output tokens that must be received for the transaction not to revert
path	address[] calldata	array of token addresses. path.length must be >= 2
to	address	recipient of the ETH
deadline	uint	unix timestamp after which the transaction will revert

Interface​

pragma solidity >=0.6.2;

import './IUniswapV2Router01.sol';

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}