Cant differentiate between Answer and Comment to Question

Please try metadata "qanda.answer" as the following and see whether it satisfy your need...

The message which is an answer will return value true while comment will return value null.

Please give me a kudo if it works.:smileyhappy:

http://<your host>/restapi/vc/messages/id/<uid>/metadata/key/qanda.answer

<response status="success">
<value type="attribute">true</value>
</response>

http://<your host>/restapi/vc/messages/id/<uid>/metadata/key/qanda.answer

<response status="success">
<value type="attribute" null="true"/>
</response>