How to add meta data for a "send" transaction

Question

I would like to attach more meta-data when sending assets using sendassetfrom just like using issue/issuemore  

Is there anyway to do it? 

In case that there are no build-in mechnism, I think I can serialize the meta-data to a JSON and store it into field "Comment". But is there any length limitation for this field? 

Answer 1

You want to use the sendwithmetadatafrom API to do this - for the amount parameter you can pass an object such as '{"asset1":50}' to send one or more assets. The final data-hex parameter can be used to attach any arbitrary transaction metadata, including a JSON (converted to hex). The limit is 4K by default, but can be easily increased using max-std-op-return-size in the blockchain parameters.