// SPDX-License-Identifier: MIT OR Apache-2.0 pragma solidity >=0.6.11; /** * @title IInterchainGasPaymaster * @notice Manages payments on a source chain to cover gas costs of relaying * messages to destination chains. */ interface IInterchainGasPaymaster { function payGasFor( address _outbox, uint256 _leafIndex, uint32 _destinationDomain ) external payable; }