hyperlane-monorepo/solidity/interfaces/IMultisigIsm.sol

// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.6.0;

import {IInterchainSecurityModule} from "./IInterchainSecurityModule.sol";

interface IMultisigIsm is IInterchainSecurityModule {
    /**
     * @notice Returns the set of validators responsible for verifying _message
     * and the number of signatures required
     * @dev Can change based on the content of _message
     * @param _message Hyperlane formatted interchain message
     * @return validators The array of validator addresses
     * @return threshold The number of validator signatures needed
     */
    function validatorsAndThreshold(bytes calldata _message)
        external
        view
        returns (address[] memory validators, uint8 threshold);
}