hyperlane

Call quoteDispatch() on the origin chain Mailbox to get the interchain gas fee, then call dispatch() with the destination domain ID, the recipient address left-padded to bytes32, and the message body, sending the quoted fee as msg.value. Delivery happens asynchronously when a relayer calls process() on the destination Mailbox.

Approve the Warp Route collateral contract to spend your tokens, call quoteGasPayment() for the destination domain, then call transferRemote() with the destination domain, bytes32-padded recipient, and amount. The origin contract locks collateral and the destination contract mints synthetic tokens.

MultisigISM verifies M-of-N validator signatures and suits most deployments. RoutingISM applies different ISMs per origin domain for varied trust assumptions. AggregationISM requires multiple sub-ISMs to pass, providing defense in depth for high-value operations.

The most common cause is missing interchain gas payment — dispatch() without sufficient msg.value gives relayers no incentive to deliver. Also verify a relayer runs for the destination chain, the recipient contract exists, and the ISM verification will pass with the available validator signatures.

Yes, Hyperlane is permissionless — you deploy the Mailbox, ISM, and ValidatorAnnounce contracts yourself using the Hyperlane CLI, then run your own validators and relayer. No governance vote or approval is required, unlike LayerZero or Wormhole.

The _sender parameter is bytes32, not address — EVM senders are left-padded with 12 zero bytes. Convert back using address(uint160(uint256(_sender))), and verify msg.sender equals the destination chain's Mailbox address, not the origin chain's.