Pair (CRC-20)

Pair (CRC-20) This documentation covers CRC-20 functionality for denominating pool tokens. For Capricorn-specific functionality, see Pair.

Code

Source Code

Events

Approval

event Approval(address indexed owner, address indexed spender, uint value);

Emitted each time an approval occurs via approve or permit.

Transfer

event Transfer(address indexed from, address indexed to, uint value);

Emitted each time a transfer occurs via transfer, transferFrom, mint, or burn.

Read-Only Functions

name

function name() external pure returns (string memory);

Returns caprion for all pairs.

symbol

function symbol() external pure returns (string memory);

Returns cap for all pairs.

decimals

function decimals() external pure returns (uint8);

Returns 18 for all pairs.

totalSupply

function totalSupply() external view returns (uint);

Returns the total amount of pool tokens for a pair.

balanceOf

function balanceOf(address owner) external view returns (uint);

Returns the amount of pool tokens owned by an address.

allowance

function allowance(address owner, address spender) external view returns (uint);

Returns the amount of liquidity tokens owned by an address that a spender is allowed to transfer via transferFrom.

DOMAIN_SEPARATOR

function DOMAIN_SEPARATOR() external view returns (bytes32);

Returns a domain separator for use in permit.

PERMIT_TYPEHASH

function PERMIT_TYPEHASH() external view returns (bytes32);

Returns a typehash for use in permit.

State-Changing Functions

approve

function approve(address spender, uint value) external returns (bool);

Lets msg.sender set their allowance for a spender.

• Emits Approval.

transfer

function transfer(address to, uint value) external returns (bool);

Lets msg.sender send pool tokens to an address.

• Emits Transfer.

transferFrom

function transferFrom(address from, address to, uint value) external returns (bool);

Sends pool tokens from one address to another.

Requires approval.

• Emits Transfer.

permit

function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

Sets the allowance for a spender where approval is granted via a signature.

• See Using Permit.

• Emits Approval.

Library

Code

Internal Functions

sortTokens

function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1);

Sorts token addresses.

pairFor

function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair);

Calculates the address for a pair without making any external calls via the SDK.

getReserves

function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB);

Calls getReserves on the pair for the passed tokens, and returns the results sorted in the order that the parameters were passed in.

quote

function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB);

Given some asset amount and reserves, returns an amount of the other asset representing equivalent value.

• Useful for calculating optimal token amounts before calling mint.

getAmountOut

function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut);

Given an input asset amount, returns the maximum output amount of the other asset (accounting for fees) given reserves.

getAmountIn

function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn);

Returns the minimum input asset amount required to buy the given output asset amount (accounting for fees) given reserves.

getAmountsOut

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

Given an input asset amount and an array of token addresses, calculates all subsequent maximum output token amounts by calling getReserves for each pair of token addresses in the path in turn, and using these to call getAmountOut.

• Useful for calculating optimal token amounts before calling swap.

getAmountsIn

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

Given an output asset amount and an array of token addresses, calculates all preceding minimum input token amounts by calling getReserves for each pair of token addresses in the path in turn, and using these to call getAmountIn.

Router

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 Source Code

Address CapswapV2Router02 is deployed at 0x34c385dd9015d663830a37CD2E75818fda6C605f on the Cube mainnet.

Read-Only Functions

facotry

function factory() external pure returns (address);

WCUBE

function WETH() external pure returns (address);

Returns the canonical WCUBE address on the CUBE mainnet.

quote See quote.

getAmountOut See getAmountOut.

getAmountIn See getAmountIn.

getAmountsOut

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

getAmountsIn

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

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 CRC-20⇄CRC-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 CRC-20⇄WCUBE pool with CUBE.

• 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 CUBE, if any, is returned to msg.sender.

• If a pool for the passed token and WCUBE 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 WCUBE/token price is <= msg.value/amountTokenDesired (token depreciates).
msg.value (amountETHDesired)	uint	The amount of CUBE to add as liquidity if the token/WCUBE price is <= amountTokenDesired/msg.value (WCUBE depreciates).
amountTokenMin	uint	Bounds the extent to which the WCUBE/token price can go up before the transaction reverts. Must be <= amountTokenDesired.
amountETHMin	uint	Bounds the extent to which the token/WCUBE 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 CUBE converted to WCUBE 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 CRC-20⇄CRC-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 CRC-20⇄WCUBE pool and receive CUBE.

• 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 CUBE 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 CUBE 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 CRC-20⇄CRC-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 CRC-20⇄WCUBE pool and receive CUBE 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 CUBE 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 CUBE 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 CUBE 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 CUBE 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 CUBE 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 CUBE 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 CUBE for as many output tokens as possible, along the route determined by the path. The first element of path must be WCUBE, 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 CUBE 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 CUBE 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 WCUBE, 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 CUBE.

Name	Type
amountOut	uint	The amount of CUBE 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 CUBE.
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);

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 CUBE.
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);

Name	Type
amountOut	uint	The amount of tokens to receive.
msg.value (amountInMax)	uint	The maximum amount of CUBE 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;

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

Name	Type
amountOut	uint	The amount of tokens to receive.
msg.value (amountInMax)	uint	The maximum amount of CUBE 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;

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

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 CUBE.
deadline	uint	Unix timestamp after which the transaction will revert.