IUniswapV3Pool.sol

// SPDX-License-Identifier: GPL-2.0-or-later
pragma solidity ^0.8.0;

interface IUniswapV3Pool {
    /// @notice The fee growth as a Q128.128 fees of token0 collected per unit of liquidity for the entire life of the pool
    /// @dev This value can overflow the uint256
    function feeGrowthGlobal0X128() external view returns (uint256);

    /// @notice The fee growth as a Q128.128 fees of token1 collected per unit of liquidity for the entire life of the pool
    /// @dev This value can overflow the uint256
    function feeGrowthGlobal1X128() external view returns (uint256);

    function swap(
        address recipient,
        bool zeroForOne,
        int256 amountSpecified,
        uint160 sqrtPriceLimitX96,
        bytes memory data
    ) external returns (int256 amount0, int256 amount1);

    function token0() external returns (address);
    function token1() external returns (address);

    struct Slot0 {
        // the current price
        uint160 sqrtPriceX96;
        // the current tick
        int24 tick;
        // the most-recently updated index of the observations array
        uint16 observationIndex;
        // the current maximum number of observations that are being stored
        uint16 observationCardinality;
        // the next maximum number of observations to store, triggered in observations.write
        uint16 observationCardinalityNext;
        // the current protocol fee as a percentage of the swap fee taken on withdrawal
        // represented as an integer denominator (1/x)%
        uint8 feeProtocol;
        // whether the pool is locked
        bool unlocked;
    }

    function slot0() external view returns (Slot0 memory slot0);
}