FIX message without body tags

1

The XMLnonFIX message contains no body tags for most FIX versions, e.g. FIX4.4.

So I assume it is perfectly valid to have messages without any body tags?

2

That is correct. This 35=n message type is a special message where it is defined with just the StandardHeader and StandardTrailer to allow carrying of any mind of XML payload within that to be transported over a FIX Session.

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3

Another one is Heartbeat(35=0) where the only field TestReqID(112) is conditionally required.

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4

Thanks @ltaikit and @gtcpm,
sorry, I was not making clear that I meant the message definition (i.e. data dictionary), so 35=n seems to be the only message that has no body tags. At least I haven’t found another occurrence.

5

In FIX Latest, the 35=n message now has the AttachmentGrp component which may help facilitate and better encode the payload content.