curl --request GET \
  --url https://api.example.com/orderbook/{marketId}

{
  "marketId": "<string>",
  "orderbook": {
    "bids": [
      {
        "price": 0.5,
        "size": 1,
        "venues": {}
      }
    ],
    "asks": [
      {
        "price": 0.5,
        "size": 1,
        "venues": {}
      }
    ]
  },
  "venueOrderbooks": {},
  "venues": {},
  "midpoint": 123,
  "spread": 123,
  "timestamp": 123
}