> For the complete documentation index, see [llms.txt](https://docs.quickswap.exchange/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.quickswap.exchange/technical-reference/smart-contracts/v2-uniswap-fork-overview/library.md). # Library ## Code [`UniswapV2Library.sol`](https://github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/libraries/UniswapV2Library.sol) ## Internal Functions ### sortTokens ```solidity function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1); ``` Sorts token addresses. ### pairFor ```solidity function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair); ``` Calculates the address for a pair without making any external calls (see Pair Addresses). ### getReserves ```solidity 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 ```solidity 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 ```solidity 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. * Used in [getAmountsOut](broken://pages/iAVxMCCpvWZ9JQIDWZa0). ### getAmountIn ```solidity 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. * Used in [getAmountsIn](broken://pages/iAVxMCCpvWZ9JQIDWZa0). ### getAmountsOut ```solidity 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](broken://pages/iAVxMCCpvWZ9JQIDWZa0) for each pair of token addresses in the path in turn, and using these to call [getAmountOut](broken://pages/iAVxMCCpvWZ9JQIDWZa0). * Useful for calculating optimal token amounts before calling swap. ### getAmountsIn ```solidity function getAmountsIn(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](broken://pages/iAVxMCCpvWZ9JQIDWZa0) for each pair of token addresses in the path in turn, and using these to call [getAmountIn](broken://pages/iAVxMCCpvWZ9JQIDWZa0). * Useful for calculating optimal token amounts before calling swap. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.quickswap.exchange/technical-reference/smart-contracts/v2-uniswap-fork-overview/library.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. 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.