Debugging messages

How to use the Hyperlane Explorer to debug messages

Visit the Explorer at

Then paste a sender/recipient address or a transaction hash into the top search field. All matching messages will be shown in the result list. Click the row for more details.

Debugging failed messages

You'll know that a message failed to process because the bar at the top of the Message Explorer will turn red and the upper right section of the page will feature error reasons indicating why the message wasn't able to process.

If your message was not delivered it can be due to several factors:

Invalid destination

If the destination domain identifier (uint32) is not known to relay clients they will have no way to deliver your message. Refer to the Domain identifiers for known domains and the canonical identifiers to use when sending messages to these destinations.

Invalid recipient

If the recipient address (bytes32) is not a contract address that implements the IMessageRecipient interface, the relayer will not be able to deliver your message.


If gas estimation of the message recipient's IMessageRecipient.handle() function fails, Relayers will not be able to deliver the message. Relayers will continue to estimate gas for message delivery, as state changes may allow for successful delivery of a previously undeliverable message.

If you have a use case which is not accommodated by this behavior, please reach out on Discord.


An underfunded message implies the Interchain gas payments made to deliver this message are insufficient.

Relayers use the eth_estimateGasRPC on the destination chain to determine the absolute cost of relaying a message. If this amount exceeds the total amount of gas paid for on the origin chain, relayers will typically refuse to deliver a message.

You can Manually pay for interchain gas to resolve this.

Using Etherscan

You can also look at the Etherscan page of the recipient on the destination chain however be aware that the processing transaction won't show up on list of transactions as you would typically imagine. The reason for that is that relayers actually call the Mailbox contracts which in turn call the handle function on the recipient. Thus, you will find evidence of processing on the under the Internal Txns tab instead

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