Messages

{
  "type": "subscribed",
  "channel": "l2Orderbook",
  "id": "BTC-USD",
  "contents": {
    "bids": [
      [
        "94500.0",
        "1.5"
      ],
      [
        "94499.0",
        "2.0"
      ]
    ],
    "asks": [
      [
        "94501.0",
        "0.8"
      ],
      [
        "94502.0",
        "3.1"
      ]
    ],
    "lastSequenceId": 1042,
    "globalSequenceId": 880421,
    "timestamp": 1780410803123456
  }
}

Market data

L2 orderbook

Endpoint: wss://api.arcus.xyz/v1/ws — one socket multiplexes every channel and RPC request. Click Connect, then send the example subscribe message below to start receiving data.

Periodic full L2 orderbook snapshots for a single market. On subscribe, the server sends the current book up to nLevels price levels per side, then continues to broadcast a fresh full snapshot every ~200ms.

No incremental updates — each message replaces the prior book state. Use l2OrderbookUpdates if you need to maintain your own local book.

WSS

ws?channel=l2Orderbook

Messages

{
  "type": "subscribed",
  "channel": "l2Orderbook",
  "id": "BTC-USD",
  "contents": {
    "bids": [
      [
        "94500.0",
        "1.5"
      ],
      [
        "94499.0",
        "2.0"
      ]
    ],
    "asks": [
      [
        "94501.0",
        "0.8"
      ],
      [
        "94502.0",
        "3.1"
      ]
    ],
    "lastSequenceId": 1042,
    "globalSequenceId": 880421,
    "timestamp": 1780410803123456
  }
}

Subscribe to L2 Orderbook

type:object

L2 Orderbook Snapshot

API documentation

Endpoints

WebSocket

Changelog

L2 orderbook