Receive

Receive an inbound message from any Hyperlane supported network

Developers must implement the IMessageRecipient interface in order to be able to receive interchain messages.
Interface
// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.6.11;
​
interface IMessageRecipient {
    /**
     * @notice Handle an interchain message
     * @param _origin Domain ID of the chain from which the message came
     * @param _sender Address of the message sender on the origin chain as bytes32
     * @param _body Raw bytes content of message body
     */
    function handle(
        uint32 _origin,
        bytes32 _sender,
        bytes calldata _body
    ) external;
}
​
Security
Access control
To ensure only valid interchain messages are accepted, it is important to require that msg.sender is a known Hyperlane Mailbox.
Developers must implement access control on handle() in order to ensure the security of interchain messages. Only a Hyperlane Mailbox contract should have permission to call this function. An example of this access control is shown below.
address constant mailbox = 0x0E3239277501d215e17a4d31c487F86a425E110B;
// for access control on handle implementations
modifier onlyMailbox() {
    require(msg.sender == mailbox);
    _;    
}
​
function handle(
    uint32 _origin,
    bytes32 _sender,
    bytes calldata _body
) external onlyMailbox {};
Interchain security modules
Developers can override Hyperlane's default Multisig ISM-based security model by specifying their own Interchain security modules.
See the Security documentation for more info on how to set the ISM used by your application.
​
Encoding
Hyperlane message senders are left-padded to bytes32 for compatibility with virtual machines that are addressed differently.
The following utility is provided in the TypeCasts library for convenience.
// alignment preserving cast
function bytes32ToAddress(bytes32 _buf) internal pure returns (address) {
    return address(uint160(uint256(_buf)));
}
Example usage
An example handle() implementation for receiving messages is provided below.
event Received(uint32 origin, address sender, bytes body);
function handle(
    uint32 _origin,
    bytes32 _sender,
    bytes memory _body
) external onlyMailbox() {
    address sender = bytes32ToAddress(_sender);
    emit Received(_origin, sender, _body);
}

Send

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Last modified 28d ago