# Pair This documentation covers Uniswap-specific functionality. For ERC-20 functionality, see Pair (ERC-20). ## Code [`UniswapV2Pair.sol`](https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2Pair.sol) ## Address See Pair Addresses. ## Events ### Mint ```solidity event Mint(address indexed sender, uint amount0, uint amount1); ``` Emitted each time liquidity tokens are created via [mint](broken://pages/IptPgkQPJaqhPg8aUdq7). ### Burn ```solidity event Burn(address indexed sender, uint amount0, uint amount1, address indexed to); ``` Emitted each time liquidity tokens are destroyed via [burn](broken://pages/IptPgkQPJaqhPg8aUdq7). ### Swap ```solidity event Swap( address indexed sender, uint amount0In, uint amount1In, uint amount0Out, uint amount1Out, address indexed to ); ``` Emitted each time a swap occurs via [swap](broken://pages/IptPgkQPJaqhPg8aUdq7). ### Sync ```solidity event Sync(uint112 reserve0, uint112 reserve1); ``` Emitted each time reserves are updated via [mint](broken://pages/IptPgkQPJaqhPg8aUdq7), [burn](broken://pages/IptPgkQPJaqhPg8aUdq7), [swap](broken://pages/IptPgkQPJaqhPg8aUdq7), or [sync](broken://pages/IptPgkQPJaqhPg8aUdq7). ## Read-Only Functions ### MINIMUM\_LIQUIDITY ```solidity function MINIMUM_LIQUIDITY() external pure returns (uint); ``` Returns `1000` for all pairs. See Minimum Liquidity. ### factory ```solidity function factory() external view returns (address); ``` Returns the factory address. ### token0 ```solidity function token0() external view returns (address); ``` Returns the address of the pair token with the lower sort order. ### token1 ```solidity function token1() external view returns (address); ``` Returns the address of the pair token with the higher sort order. ### getReserves ```solidity function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast); ``` Returns the reserves of token0 and token1 used to price trades and distribute liquidity. See Pricing. Also returns the `block.timestamp` (mod `2**32`) of the last block during which an interaction occured for the pair. ### price0CumulativeLast ```solidity function price0CumulativeLast() external view returns (uint); ``` See Oracles. ### price1CumulativeLast ```solidity function price1CumulativeLast() external view returns (uint); ``` See Oracles. ### kLast ```solidity function kLast() external view returns (uint); ``` Returns the product of the reserves as of the most recent liquidity event. See Protocol Charge Calculation. ## State-Changing Functions ### mint ```solidity function mint(address to) external returns (uint liquidity); ``` Creates pool tokens. * Emits [Mint](broken://pages/IptPgkQPJaqhPg8aUdq7), [Sync](broken://pages/IptPgkQPJaqhPg8aUdq7), Transfer. ### burn ```solidity function burn(address to) external returns (uint amount0, uint amount1); ``` Destroys pool tokens. * Emits [Burn](broken://pages/IptPgkQPJaqhPg8aUdq7), [Sync](broken://pages/IptPgkQPJaqhPg8aUdq7), Transfer. ### swap ```solidity function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external; ``` Swaps tokens. For regular swaps, `data.length` must be `0`. Also see Flash Swaps. * Emits [Swap](broken://pages/IptPgkQPJaqhPg8aUdq7), [Sync](broken://pages/IptPgkQPJaqhPg8aUdq7). ### skim ```solidity function skim(address to) external; ``` See the whitepaper. ### sync ```solidity function sync() external; ``` See the whitepaper. * Emits [Sync](broken://pages/IptPgkQPJaqhPg8aUdq7). ## Interface ```solidity import '@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol'; ``` ```solidity pragma solidity >=0.5.0; interface IUniswapV2Pair { event Approval(address indexed owner, address indexed spender, uint value); event Transfer(address indexed from, address indexed to, uint value); function name() external pure returns (string memory); function symbol() external pure returns (string memory); function decimals() external pure returns (uint8); function totalSupply() external view returns (uint); function balanceOf(address owner) external view returns (uint); function allowance(address owner, address spender) external view returns (uint); function approve(address spender, uint value) external returns (bool); function transfer(address to, uint value) external returns (bool); function transferFrom(address from, address to, uint value) external returns (bool); function DOMAIN_SEPARATOR() external view returns (bytes32); function PERMIT_TYPEHASH() external pure returns (bytes32); function nonces(address owner) external view returns (uint); function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external; event Mint(address indexed sender, uint amount0, uint amount1); event Burn(address indexed sender, uint amount0, uint amount1, address indexed to); event Swap( address indexed sender, uint amount0In, uint amount1In, uint amount0Out, uint amount1Out, address indexed to ); event Sync(uint112 reserve0, uint112 reserve1); function MINIMUM_LIQUIDITY() external pure returns (uint); function factory() external view returns (address); function token0() external view returns (address); function token1() external view returns (address); function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast); function price0CumulativeLast() external view returns (uint); function price1CumulativeLast() external view returns (uint); function kLast() external view returns (uint); function mint(address to) external returns (uint liquidity); function burn(address to) external returns (uint amount0, uint amount1); function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external; function skim(address to) external; function sync() external; } ``` ## ABI ```typescript import IUniswapV2Pair from '@uniswap/v2-core/build/IUniswapV2Pair.json' ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.quickswap.exchange/technical-reference/smart-contracts/v2/pair.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.