org.apache.synapse.transport.fix.FIXTransportSender acts as the transport sender implementation. These classes can be found in the
<ESB_HOME/repository/components/plugins/synapse-fix-transport.jar file. The transport implementation is based on Quickfix/J open source FIX engine and hence the following additional dependencies are required to enable the FIX transport.
This From WSO2 ESB 4.0.2 onwards, this transport supports JMX (New in version 4.0).
Download Quickfix/J from here and in the distribution archive you will find all the dependencies listed above. Also please refer to Quickfix/J documentation on configuring FIX acceptors and initiators.