Router02

Because routers are stateless and do not hold token balances, they can be replaced safely and trustlessly, if necessary. This may happen if more efficient smart contract patterns are discovered, or if additional functionality is desired. For this reason, routers have release numbers, starting at 01. This is currently recommended release, 02.

Code

UniswapV2Router02.sol

Address

UniswapV2Router02 is deployed at 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on the Ethereum mainnet, and the Ropsten, Rinkeby, Görli, and Kovan testnets. It was built from commit 6961711.

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 Ropsten, Rinkeby, Görli, or Kovan testnets.

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.

Name	Type
tokenA	address	A pool token.
tokenB	address	A pool token.
amountADesired	uint	The amount of tokenA to add as liquidity if the B/A price is <= amountBDesired/amountADesired (A depreciates).
amountBDesired	uint	The 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.
amountA	uint	The amount of tokenA sent to the pool.
amountB	uint	The amount of tokenB sent to the pool.
liquidity	uint	The 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.

Name	Type
token	address	A pool token.
amountTokenDesired	uint	The amount of token to add as liquidity if the WETH/token price is <= msg.value/amountTokenDesired (token depreciates).
msg.value (amountETHDesired)	uint	The amount of ETH to add as liquidity if the token/WETH price is <= amountTokenDesired/msg.value (WETH depreciates).
amountTokenMin	uint	Bounds the extent to which the WETH/token price can go up before the transaction reverts. Must be <= amountTokenDesired.
amountETHMin	uint	Bounds the extent to which the token/WETH price can go up before the transaction reverts. Must be <= msg.value.
to	address	Recipient of the liquidity tokens.
deadline	uint	Unix timestamp after which the transaction will revert.
amountToken	uint	The amount of token sent to the pool.
amountETH	uint	The amount of ETH converted to WETH and sent to the pool.
liquidity	uint	The 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.

Name	Type
tokenA	address	A pool token.
tokenB	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountAMin	uint	The minimum amount of tokenA that must be received for the transaction not to revert.
amountBMin	uint	The 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.
amountA	uint	The amount of tokenA received.
amountB	uint	The 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.

Name	Type
token	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountTokenMin	uint	The minimum amount of token that must be received for the transaction not to revert.
amountETHMin	uint	The 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.
amountToken	uint	The amount of token received.
amountETH	uint	The 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, thanks to permit.

Name	Type
tokenA	address	A pool token.
tokenB	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountAMin	uint	The minimum amount of tokenA that must be received for the transaction not to revert.
amountBMin	uint	The 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	The v component of the permit signature.
r	bytes32	The r component of the permit signature.
s	bytes32	The s component of the permit signature.
amountA	uint	The amount of tokenA received.
amountB	uint	The 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, thanks to permit.

Name	Type
token	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountTokenMin	uint	The minimum amount of token that must be received for the transaction not to revert.
amountETHMin	uint	The 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	The v component of the permit signature.
r	bytes32	The r component of the permit signature.
s	bytes32	The s component of the permit signature.
amountToken	uint	The amount of token received.
amountETH	uint	The 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.

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

Name	Type
token	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountTokenMin	uint	The minimum amount of token that must be received for the transaction not to revert.
amountETHMin	uint	The 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.
amountETH	uint	The 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.

Name	Type
token	address	A pool token.
liquidity	uint	The amount of liquidity tokens to remove.
amountTokenMin	uint	The minimum amount of token that must be received for the transaction not to revert.
amountETHMin	uint	The 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	The v component of the permit signature.
r	bytes32	The r component of the permit signature.
s	bytes32	The s component of the permit signature.
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).

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

Name	Type
amountIn	uint	The amount of input tokens to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the output tokens.
deadline	uint	Unix timestamp after which the transaction will revert.
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).

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

Name	Type
amountOut	uint	The amount of output tokens to receive.
amountInMax	uint	The maximum amount of input tokens that can be required before the transaction reverts.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the output tokens.
deadline	uint	Unix timestamp after which the transaction will revert.
amounts	uint[] memory	The 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).

Name	Type
msg.value (amountIn)	uint	The amount of ETH to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the output tokens.
deadline	uint	Unix timestamp after which the transaction will revert.
amounts	uint[] memory	The 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.

Name	Type
amountOut	uint	The amount of ETH to receive.
amountInMax	uint	The maximum amount of input tokens that can be required before the transaction reverts.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of ETH.
deadline	uint	Unix timestamp after which the transaction will revert.
amounts	uint[] memory	The 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.

Name	Type
amountIn	uint	The amount of input tokens to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the ETH.
deadline	uint	Unix timestamp after which the transaction will revert.
amounts	uint[] memory	The 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.

Name	Type
amountOut	uint	The amount of tokens to receive.
msg.value (amountInMax)	uint	The maximum amount of ETH that can be required before the transaction reverts.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the output tokens.
deadline	uint	Unix timestamp after which the transaction will revert.
amounts	uint[] memory	The 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.

Name	Type
amountIn	uint	The amount of input tokens to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
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.

Name	Type
msg.value (amountIn)	uint	The amount of ETH to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
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.

Name	Type
amountIn	uint	The amount of input tokens to send.
amountOutMin	uint	The minimum amount of output tokens that must be received for the transaction not to revert.
path	address[] calldata	An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
to	address	Recipient of the ETH.
deadline	uint	Unix timestamp after which the transaction will revert.

Interface

import '@uniswap/v2-periphery/contracts/interfaces/IUniswapV2Router02.sol';

pragma solidity >=0.6.2;

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    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);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    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);
    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);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

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;
}

ABI

import IUniswapV2Router02 from '@uniswap/v2-periphery/build/IUniswapV2Router02.json'

https://unpkg.com/@uniswap/v2-periphery@1.1.0-beta.0/build/IUniswapV2Router02.json