README.md

Universal Uniswap V2 Callback

Universal handler for any Uniswap-V2-like callback.

Every fork of Uniswap V2 protocol usually implements their own callback function, which generally follows the same format. Since there are hundreds of forks deployed across different chains, it becomes unfeasible to manually track and implement callback function for each of them. Besides, doing so would increase deployed contract size for each new supported fork.

UniswapV2CallbackHandler solves this problem by using a fallback function, and manually decoding msg.data. Decoded result is validated to make sure it conforms to the expected callback structure.

Using the universal callback with validation is more expensive by 1 gas.

Install

forge install kr1ptal/universal-uniswap-v2-callback

Usage

import "universal-uniswap-v2-callback/UniswapV2CallbackHandler.sol";

contract UniversalCallbackHandler is UniswapV2CallbackHandler {
    function handleUniswapV2Callback(uint256 amount0, uint256 amount1, bytes calldata data) internal override {
        // callback code
    }
}