SBE BBO Integration Guide

Overview

Field	Description
Topic	books1
TemplateId	1002
Format	SBE binary frame (opcode = 2), little-endian
Depth	Provides real-time Level 1 best bid/ask prices and corresponding order sizes
Units	Timestamps in microseconds (µs), but only accurate to milliseconds. Append 000 to a millisecond timestamp to get the microsecond format. E.g., millisecond timestamp 1726233600001 corresponds to µs timestamp 1726233600001000
Update Frequency	Real-time (pushed on every BBO change)

---

Connection

• WebSocket URL: wss://ws.bitget.com/v3/ws/public/sbe
• Heartbeat: Send text frame "ping" every 30 seconds, server responds with "pong"
• Message Protocol: JSON text frames during subscription phase; SBE binary frames during market data push phase, distinguished by WebSocket opCode (opCode=1 for text, opCode=2 for binary)

---

Subscription Flow

1. Send Subscription Request

{
  "op": "subscribe",
  "args": [
    {
      "instType": "usdt-futures",
      "topic": "books1",
      "symbol": "BTCUSDT"
    }
  ]
}

Parameter Description:

Parameter	Type	Description
instType	string	Product type: spot usdt-futures coin-futures
topic	string	Fixed value: books1
symbol	string	Symbol name, e.g. BTCUSDT, ETHUSDT

2. Subscription Confirmation

{
  "event": "subscribe",
  "arg": {
    "instType": "usdt-futures",
    "topic": "books1",
    "symbol": "BTCUSDT"
  }
}

3. Receiving Data

After subscription confirmation, SBE binary frames are pushed in real-time whenever the BBO changes.

4. Unsubscribe

{
  "op": "unsubscribe",
  "args": [
    {
      "instType": "usdt-futures",
      "topic": "books1",
      "symbol": "BTCUSDT"
    }
  ]
}

---

SBE Message Structure

Best bid/ask price and corresponding size for a specified trading pair.

Price/Size Calculation Formula

actual_value = mantissa × 10^exponent

Example: mantissa = 123456, exponent = -4, represents 12.3456 (actual_value = mantissa × 10 ^ exponent)

Common Message Header (8 bytes)

All SBE messages must include a fixed 8-byte header for parsing and identifying subsequent data.

Field	Type	Length (Byte)	Description
blockLength	uint16	2	Root block length
templateId	uint16	2	Channel unique identifier, fixed value = 1002
schemaId	uint16	2	Schema ID
version	uint16	2	Schema version

Message Field Definitions

#	Field	Type	Description
-	messageHeader	Composite	Fixed header
1	ts	uint64	Matching engine timestamp µs timestamp, but only accurate to milliseconds. Append 000 to a millisecond timestamp to get the microsecond format. E.g., millisecond timestamp 1726233600001 → µs 1726233600001000
2	bid1Price	int64	Best bid price
3	bid1Size	int64	Best bid size
4	ask1Price	int64	Best ask price
5	ask1Size	int64	Best ask size
6	priceExponent	int8	Price exponent
7	sizeExponent	int8	Size exponent
8	seq	uint64	Depth sequence number, used for message ordering and packet loss detection
100	padding	uint8	Padding bytes
200	symbol	varString[8]	Symbol name, UTF-8 format

Binary Layout Overview

┌─────────────┬──────────────┬──────────┐
│ Header (8B) │ Root (56B)   │ Symbol   │
└─────────────┴──────────────┴──────────┘

Total message size: 8 + 56 + 1 + len(symbol) = approximately 72 bytes

---

Decoding Example

Raw Binary (hex)

38 00 EA 03 01 00 02 00  <- header: blockLength=56, templateId=1002, schemaId=1, version=2
01 80 C6 A7 86 3E 06 00  <- ts (uint64 LE)
4E 3C 64 00 00 00 00 00  <- bid1Price = 6569038
98 3A 00 00 00 00 00 00  <- bid1Size  = 15000
52 3C 64 00 00 00 00 00  <- ask1Price = 6569042
20 4E 00 00 00 00 00 00  <- ask1Size  = 20000
FE                        <- priceExponent = -2
FC                        <- sizeExponent  = -4
01 00 00 00 00 00 00 00  <- seq (uint64 LE) = 1
00 00 00 00 00 00        <- padding6
07 42 54 43 55 53 44 54  <- symbol: length=7, "BTCUSDT"

Decoded JSON

{
  "header": {
    "block_length": 56,
    "template_id": 1002,
    "schema_id": 1,
    "version": 2
  },
  "ts": 1700000000000001,
  "bid1_price": "65664.78",
  "bid1_size": "1.5000",
  "ask1_price": "65665.78",
  "ask1_size": "2.0000",
  "price_exponent": -2,
  "size_exponent": -4,
  "seq": 1,
  "symbol": "BTCUSDT"
}

---

Python Integration Example

"""Bitget books1 (BBO) SBE WebSocket subscription example"""
import asyncio
import json
import struct
from decimal import Decimal
import websockets

WS_URL    = "wss://ws.bitget.com/v3/ws/public/sbe"
INST_TYPE = "usdt-futures"
SYMBOL    = "BTCUSDT"
TOPIC     = "books1"


def decode_bbo(data: bytes) -> dict:
    """Decode BestBidAsk (templateId=1002) SBE frame"""
    block_length, template_id, schema_id, version = struct.unpack_from('<HHHH', data, 0)
    assert template_id == 1002, f"unexpected templateId: {template_id}"

    offset     = 8
    base       = offset
    ts,         = struct.unpack_from('<Q', data, offset); offset += 8
    bid1_price, = struct.unpack_from('<q', data, offset); offset += 8
    bid1_size,  = struct.unpack_from('<q', data, offset); offset += 8
    ask1_price, = struct.unpack_from('<q', data, offset); offset += 8
    ask1_size,  = struct.unpack_from('<q', data, offset); offset += 8
    price_exp,  = struct.unpack_from('<b', data, offset); offset += 1
    size_exp,   = struct.unpack_from('<b', data, offset); offset += 1
    seq,        = struct.unpack_from('<Q', data, offset); offset += 8

    # Skip padding, based on blockLength
    offset = base + block_length

    # symbol (varString8)
    sym_len, = struct.unpack_from('<B', data, offset); offset += 1
    symbol = data[offset:offset + sym_len].decode('utf-8')

    to_dec = lambda m, e: Decimal(m) * Decimal(10) ** e

    return {
        "ts": ts,
        "bid1_price": str(to_dec(bid1_price, price_exp)),
        "bid1_size":  str(to_dec(bid1_size,  size_exp)),
        "ask1_price": str(to_dec(ask1_price, price_exp)),
        "ask1_size":  str(to_dec(ask1_size,  size_exp)),
        "price_exponent": price_exp,
        "size_exponent":  size_exp,
        "seq": seq,
        "symbol": symbol,
    }


async def main():
    async with websockets.connect(WS_URL) as ws:
        # Subscribe
        await ws.send(json.dumps({
            "op": "subscribe",
            "args": [{"instType": INST_TYPE, "topic": TOPIC, "symbol": SYMBOL}]
        }))
        print(f"[SUB] {INST_TYPE} {TOPIC} {SYMBOL}")

        # Heartbeat
        async def ping_loop():
            while True:
                await asyncio.sleep(20)
                await ws.send("ping")
                print("[PING] sent")

        asyncio.create_task(ping_loop())

        async for message in ws:
            if isinstance(message, bytes):
                try:
                    msg = decode_bbo(message)
                    ts_ms = msg['ts'] // 1000
                    spread = Decimal(msg['ask1_price']) - Decimal(msg['bid1_price'])
                    print(f"\n[BBO] {msg['symbol']}  ts={ts_ms}ms  seq={msg['seq']}")
                    print(f"  bid: price={msg['bid1_price']}  size={msg['bid1_size']}")
                    print(f"  ask: price={msg['ask1_price']}  size={msg['ask1_size']}")
                    print(f"  spread: {spread}")
                except Exception as e:
                    print(f"[ERROR] {e}  raw={message.hex()}")
            else:
                if message == "pong":
                    print("[PONG] received")
                else:
                    print(f"[TEXT] {message}")


if __name__ == "__main__":
    asyncio.run(main())