You can access headers by using a JavaCompute node.
If an input node receives an input message that includes message headers that the input node recognizes, the node starts the correct parser for each header. Parsers are supplied for most WebSphere® MQ headers. The following topics provide guidance for accessing the information in the MQMD and MQRFH2 headers that you can follow when accessing other headers that are present in your messages.
For further details of the contents of these and other WebSphere MQ headers for which IBM® Integration Bus provides a parser, see Element definitions for message parsers.