OSS L1 Snapshot

WSProductionwss://ws.btse.com/ws/oss/futuresTestnetwss://testws.btse.io/ws/oss/futures

Subscribe to the best bid / best ask (Level 1) for a market. Topic format: snapshotL1:<symbol> (e.g. snapshotL1:BTC-PERP)

Each message is a full snapshot of the current best bid / best ask. The bids and asks arrays each contain a single [price, size] tuple representing the top of book, and the type field is always snapshotL1.

Bids and asks are sent in price and size tuples as strings to preserve precision; clients should parse them with a high-precision type (e.g. BigDecimal, decimal.js) before performing arithmetic.

Because every push is a full snapshot, clients can simply overwrite the local copy on each message — there is no sequence number, and no delta merging is required. If the connection drops, re-subscribe to the topic to resume receiving updates.

Response Content

Name	Type	Required	Description
topic	String	Yes	WebSocket topic
data	Object	Yes	Data object

Data Object:

Name	Type	Required	Description
bids	String[][]	Yes	Best bid [price, size]
asks	String[][]	Yes	Best ask [price, size]
symbol	String	Yes	Market symbol
type	String	Yes	Always snapshotL1
timestamp	Long	Yes	Orderbook timestamp (ms)

example

Request

{
  "op": "subscribe",
  "args": [
    "snapshotL1:BTC-PERP"
  ]
}

Request

{
  "op": "unsubscribe",
  "args": [
    "snapshotL1:BTC-PERP"
  ]
}

Response

{
  "topic": "snapshotL1:BTC-PERP",
  "data": {
    "bids": [
      [
        "122160.1",
        "69350"
      ]
    ],
    "asks": [
      [
        "122133.3",
        "1000"
      ]
    ],
    "type": "snapshotL1",
    "symbol": "BTC-PERP",
    "timestamp": 1565135165600
  }
}