Session level message rejection rule on message type (tag 35)

Hi All,

I am a new member of the site and also the first question.

We are using OnixS FIX (Version 5 SP2) engine library and we would like to process AE (35=AE) and W (35=W) types of messages only. It means if any other types of messages are incoming via session, then they should be rejected automatically by FIX session. I have searched through the forum and found a post (Reject of unsupported FIX messages) but somehow I couldn’t find / gather how can I achieve that in OnixS library.

If anyone has ever done that then can you please guide me.


I am not familiar with the OnixS library but it should allow you to send a BusinessMessageReject(35=j) with BusinessRejectReason(380) = 3 (Unsupported Message Type) in response to messages received other than 35=AE or 35=W.

Thank you Hanno for your time and effort, I greatly appreciate it.

I was wondering if there is any documented way of customizing those session level rules. I tried to find it on OnixS documentation but couldn’t find how to make custom rules. Though OnixS does mention here that it is implemented already for default rules.

The OnixS link is for the session level Reject(35=3) message, not for BusinessMessageReject(35=j).
SessionRejectReason(373) has a union data type of int and Reserved100Plus, i.e. you can customize with user-defined values of 100 or above.