How detect audiosocket error code ?

Hi,
I am considering call transfer depend on the audiosocket error code in payload.

Is there any variables set by audiosocket in the Asterisk dialplan to determine following call flow?

It will be very helpful and expanding use case of audiosocket?

Also, do you any hint or idea for integration with pjsua, pjsip based softphone?

Thanks in advance for your advice.