I would like to add external 3rd party payment clients and implement a kind of “challenge-response” pattern to correlate payments (eg. the service gives you a random number and you have to pay Libra with the signed number in a extra data field).
As I understand it this extra data could be on rawTransaction or on “Coin-Transaction”/Smart Contract level, but I couldn’t find a possibility. Is there something like “extraData” on transaction level or planned to be included on LibraCoin level (eg.
transfer(_to, _amount, _extraData))?