The FIX transport

HCL OneTest API uses the Financial Information eXchange (FIX) transport to connect to applications that use the FIX protocol, acting as a client (initiator) or as a server (acceptor). Additionally, HCL OneTest API uses packet capture software to record FIX conversations over the FIX transport.

HCL OneTest API supports FIX versions 4.0 through 4.4. The FIX transport is created when you set up a physical FIX Connection component in Architecture School. Creating the transport also creates a schema, with which you can do the following actions:
  • View or modify the schema in the Schema Library.
  • Apply the schema to messages in the same way that you apply a FIX dictionary (see FIX dictionaries).
Note: HCL OneTest API uses the QuickFIX/J engine (Java version of QuickFIX) FIX implementation. For more information, refer to

Sequence numbers

The FIX protocol requires each application to maintain two sequence numbers per session: incoming and outgoing. The numbers are independent of each other, although sequence numbers are always found in Field 34 of the message (commonly referred to as "Tag 34"). The application increments the outgoing sequence number and sets Field 34 equal to that value in each outgoing message. For incoming messages, the application increments the stored incoming sequence number and verifies that it matches the value of Field 34 of the incoming message.

Two settings for the FIX transport affect the way a stub uses sequence numbers:
  • Reset sequence numbers on logon on the Session page
  • Storage type on the Storage page

These effects are shown in the following table:

Table 1. Transport settings and sequence numbers
Value of "Reset sequence numbers..." Storage type Header
Selected File or In memory Sequence numbers are reset with each logon.
Clear File Sequence numbers are maintained between multiple runs of the stub and multiple runs of HCL OneTest API.
Clear In memory Sequence numbers are maintained between multiple logons, but cleared if the stub is restarted.

Create the FIX transport

The FIX transport is created when you create a physical FIX Connection resource in the Architecture School.

In Architecture School, you can create a resource in two ways:

  • In the Logical View, either select General > FIX Endpoint from the toolbar, or right-click a TIBCO Rendezvous Bus and select New > General > FIX Endpoint.
  • In the Physical View, select General > FIX Connection from the toolbar.

Each physical FIX Connection resource represents a FIX transport that can be selected and configured later on.