Standard Header and Trailer
Standard Header and Trailer
This documentation uses | to represent the FIX field separator (byte 0x01). It should be replaced by 0x01 in actual messages.
Standard Header
The header identifies the message type, length, destination, sequence number, origination point and time.
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 8 | BeginString | string | Y | Must be "FIX.4.4" |
| 9 | BodyLength | number | Y | Length of the message body in bytes |
| 35 | MsgType | string | Y | Message Type |
| 34 | MsgSeqNum | number | Y | Integer message sequence number |
| 43 | PossDupFlag | boolean | N | Indicates possible retransmission of message with this sequence number |
| 49 | SenderCompID | string | Y | See FIX Endpoints for details |
| 56 | TargetCompID | string | Y | See FIX Endpoints for details |
| 52 | SendingTime | UTCTimestamp | Y | Time when the message is being sent out from FIX Gateway |
| 97 | PossResend | boolean | N | Indicates that message may contain information sent under another sequence number |
Processing PossDupFlag and PossResend:
- PossDupFlag (43=Y) — if a message with this sequence number has been previously received, ignore message; if not, process normally.
- PossResend (97=Y) — forward message to application and determine if previously received (i.e. verify order id and parameters).
Standard Trailer
Each FIX message is terminated by a Standard Trailer as a message delimiter as well as containing the checksum value.
| Tag | Name | Type | Required | Description |
|---|---|---|---|---|
| 10 | CheckSum | string | Y | Three bytes, simple checksum. Always last field in message |