API Reference

Logon <A>

The Logon <A> message authenticates a user and starts a session. It must be the first message sent by any application requesting to initiate a FIX session. A message of the same type will be sent to acknowledge the logon.

Tag

Field Name

Required

Comments

Standard Header

Yes

MsgType <35> = A

98

EncryptMethod

Yes

Method of encryption
Valid values:
0 – None / other

108

HeartBtInt

Yes

Heartbeat interval in seconds.
Valid values: 30 (30 seconds)

141

ResetSeqNumFlag

No

Indicates that the both sides of the FIX session should reset sequence numbers
Valid values:
Y – Yes, reset sequence numbers
N – No (Default)

553

Username

Yes

User Id (provided during onboarding)

554

Password

Yes

Password (provided during onboarding)

1137

DefaultApplVerID

Yes*

The default version of FIX message used in this session:

  • 9 = FIX50SP2
  • Required for FIX 5.0 SP2 only

Standard trailer

Yes