Is there a way to find out how much I earned in fees from just the UniswapPair V2 contract?

Question

Let's say I add liquidity to the ETH-USDT pool, then I remove liquidity some time later.

In between that time, trades have happened and people have added and removed liquidity too.

I only have what's inside the Pair contract, so:

• reserve0
• reserse1
• price as a ratio reserve0/reserve1

I don't have access to:

• History of swaps that have occurred
• History of other people adding/removing liquidity

Is it possible to figure out how much I've earned in fees?

Answer 1

Assuming you are asking about Uniswap V3 - You can call positions:

    function positions(bytes32 key)
        external
        view
        returns (
            uint128 _liquidity,
            uint256 feeGrowthInside0LastX128,
            uint256 feeGrowthInside1LastX128,
            uint128 tokensOwed0,
            uint128 tokensOwed1
        );

This returns the token fees due to a position in both token0 and token1.