In the tables below, the Req column indicates whether a field is required:
Y = Required, N = Optional, C = Conditional on another field. ↳ denotes a field within a repeating group.Session Management Messages
(A) Logon
Initiates FIX session connection between client and server.Standard Header Fields
Logon Message Fields
(5) Logout
Terminates FIX session gracefully.(0) Heartbeat
Maintains session connectivity and confirms system responsiveness.(1) TestRequest
Validates session responsiveness when no messages received within HeartBtInt period.(3) Reject
Indicates session-level rejection of a received message.(2) ResendRequest
Requests retransmission of messages when gap detected in sequence numbers.(4) SequenceReset
Resets message sequence numbers or fills sequence gaps.Order Entry Messages
All messages in this section must include the Standard Header fields. See (A) Logon for the full field list.