Message Header
Each message begins with the following SBE message header:| Field | Name | Type | Length | Description |
|---|---|---|---|---|
| 1 | protocolId | uint8 | 1 | Constant (= 0xF1) |
| 2 | flags | uint8 | 1 | Bitset of flags. 0x01 = resend |
| 3 | messageLength | uint16 | 2 | Total length of message including this header and body. |
| 4 | sequenceNumber | uint32 | 4 | Sequence number of message. |
| 5 | lastProcessedSeqNum | uint32 | 4 | Sequence number of last message received/processed by the sender of this message. |
| 6 | reserved | 4 | Padding | |
| 7 | sendTimeEpochNanos | int64 | 8 | Sending time in nanoseconds since epoch. |
| 8 | blockLength | uint16 | 2 | Length of message root block in bytes, before variable data commences. |
| 9 | templateId | uint16 | 2 | Message type Id |
| 10 | schemaId | uint16 | 2 | Message schema Id (1100 for admin/session messages, 1101 for orders) |
| 11 | version | uint16 | 2 | Message version number |