There's no need to. Different agents will have different copies of the same message, that's a given. If the sender ensures that a UUID is attached to a single s

There's no need to. Different agents will have different copies of the same message, that's a given. If the sender ensures that a UUID is attached to a single specific message and never re-used (though they may retry to send the exact same message multiple times), then there is no risk that multiple receivers would have different versions of a message and therefore consensus is guaranteed without even having to talk to each other. If you assume that the sender cannot be trusted to not reuse a single UUID for multiple messages (e.g. to trick the receiver), you can still work around that limitation by computing and comparing message hashes (e.g. sha256) on the receiver side... Don't even need UUIDs. Every time you receive a message, you can hash it and check if you're received a message with this hash before (storing the hash of each message as it is received). You can use the hash in place of a UUID though in this case you probably need to add some index to each message to ensure that each hash is unique over time (since a message with the exact same payload will be counted as the same message, even if broadcast a long time apart).