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 |