The logon message authenticates a user establishing a connection to a remote system. The logon message must be the first message sent by the application requesting to initiate a FIX session.

Added in protocol FIX.2.7

See in: FIX.4.0, FIX.4.1, FIX.4.2, FIX.4.3, FIX.4.4, FIX.5.0SP1, FIX.5.0SP2, FIX.5.0SP2 EP240, FIXT.1.1.

Field or Component Name Description Is Required Added Is Deprecated
Block StandardHeader MsgType = A Y FIX.2.7
98 EncryptMethod (Always unencrypted) Y FIX.2.7
108 HeartBtInt Note same value used by both sides Y FIX.3.0
95 RawDataLength Required for some authentication methods FIX.2.7
96 RawData Required for some authentication methods FIX.2.7
141 ResetSeqNumFlag Indicates both sides of a FIX session should reset sequence numbers FIX.4.1
789 NextExpectedMsgSeqNum Optional, alternative via counterparty bi-lateral agreement message gap detection and recovery approach (see "Logon Message NextExpectedMsgSeqNum Processing" section) FIX.4.4
383 MaxMessageSize Can be used to specify the maximum number of bytes supported for messages received FIX.4.2
ImplicitBlockRepeating MsgTypeGrp FIX.4.4
464 TestMessageIndicator Can be used to specify that this FIX session will be sending and receiving "test" vs. "production" messages. FIX.4.3
553 Username FIX.4.3
554 Password Note: minimal security exists without transport-level encryption. FIX.4.3
1137 DefaultApplVerID The default version of FIX being carried over this FIXT session Y FIX.4.4
Block StandardTrailer Y FIX.2.7