All messages (administrative or application) are preceded by a Standard Header. In addition to providing the identification of FIX Session participants, the Standard Header identifies the Message Type (Tag 35), Message Length (Tag 9), Origination times (Tag 52 and Tag 122) and Message Sequence order (Tag 34). The Standard Header also offers additional information on FIX Session authentication, resent messages, duplicated messages, and message routing and delivery.
| Tag | Field Name | Req'd | Comments |
|---|---|---|---|
| 8 | BeginString | Y | FIX.4.2 |
| 9 | BodyLength | Y | Length of Current Message |
| 35 | MsgType | Y | Message Type |
| 49 | SenderCompID | Y | T4 Firm Name (outbound from FIX API server). T4 Application Name (inbound into FIX API server). |
| 56 | TargetCompID | Y | T4 Application Name (outbound from FIX API server). T4 Firm Name (inbound into FIX API server). |
| 90 | SecureDataLen | N | Length of SecureData (Tag 91) field. Used only in Login Message. |
| 91 | SecureData | N | T4 application license code. Used only in Login Message. |
| 34 | MsgSeqNum | Y | Sequence number of current message |
| 50 | SenderSubID | N | T4 User/Trader Name. Message originator. Conditionally required for non-administrative messages when in Multi-Trader mode. |
| 57 | TargetSubID | N | T4 User/Trader Name. Message originator. |
| 43 | PossDupFlag | N | “Y(es)” or “N(o)” Flag that indicates possible retransmission of message with this sequence number |
| 97 | PossResend | N | “Y(es)” or “N(o)” Flag that indicates that the current message may contain information that has been sent under another sequence number |
| 52 | SendingTime | Y | Time of message transmission - This is the UTC time the message is built within the CTS FIX API server. |
| 122 | OrigSendingTime | N | Original time of message transmission when transmitting orders as the result of a Resend Request - expressed in UTC (Universal Time Coordinated) |
| 369 | LastMsgSeqNumProcessed | N | The last Sequence Number (Tag 34) value received by the T4 FIX API |