Sessions

The following session messages are supported in both directions:

Table 1. Session Messages
MessageTypeComment
LogonABegin session (or resume a broken session).
Heartbeat0
Test RequestC
Resend Request2
Reject3Malformed message or improper session level handling.
Sequence Reset4Both Gap Fill (GapFillFlag = Y) and Reset.
Logout5Used to gracefully close session.
Cboe Titanium U.S. Options FIX Specification - Sessions | Cboe