aave-protocol-v2/contracts/interfaces/IExchangeAdapter.sol

// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.6.8;

import {IERC20} from '@openzeppelin/contracts/token/ERC20/IERC20.sol';

interface IExchangeAdapter {
  event Exchange(
    address indexed from,
    address indexed to,
    address indexed platform,
    uint256 fromAmount,
    uint256 toAmount
  );

  function approveExchange(IERC20[] calldata _tokens) external;

  function exchange(
    address _from,
    address _to,
    uint256 _amount,
    uint256 _maxSlippage
  ) external returns (uint256);
}