Uniswap V3 version of V2's getAmountsIn/getAmountsOut?

Question

In V2, you could call the router contract with getAmountsIn or getAmountsOut, to see how much of a token you would get from swapping x amount of a token, or how many tokens you would have to swap to get x amount of a token.

I'm really struggling with figuring out how to achieve the same with V3. Quoter contract has them as transactions (getQuotedAmountsIn/getQuotedAmountsOut). Is there a way in V3 to calculate the output of a swap without actually sending a transaction and paying gas?

Seems like any similar question is left unanswered. Hoping for some help on this one.

Answer 1

You can try using Quoter.sol's function quoteExactInputSingle(), it gives the expected amount for the swap in a given single pool. There are other functions for other kinds of swaps.

Github: https://github.com/Uniswap/v3-periphery/blob/v1.0.0/contracts/interfaces/IQuoter.sol

Deployment address: 0xb27308f9F90D607463bb33eA1BeBb41C27CE5AB6 (Ethereum mainnet, testnet, polygon, etc.)

Answer 2

Using oracle in solidity

import "@uniswap/v3-periphery/contracts/libraries/OracleLibrary.sol";

// you declare first and then initalize in the constructor
address public immutable token0;
address public immutable token1;
address public immutable pool;

function getQuote(
    address tokenIn,
    uint128 amountIn,
    // seconds ago is the duration of Twap
    uint32 secondsAgo
) external view returns (uint amountOut) {
    // add your require logic here
    address tokenOut = tokenIn == token0 ? token1 : token0;
    (int24 tick, uint128 harmonicMeanLiquidity ) = OracleLibrary.consult(pool, secondsAgo);
    amountOut = OracleLibrary.getQuoteAtTick(tick, amountIn, tokenIn, tokenOut);
}