Order book

Two views of the same data. tier=light returns every top-of-book update — bid, ask, sizes — for both outcomes. tier=full returns 25 levels of depth on each side, captured at microsecond resolution.

Get book history

GET/v1/markets/{conditionId}/book

Query parameters

Field	Type	Description
tier	string	`light` (top-of-book quotes, default) or `full` (L25 snapshots, Pro only).
outcome	string	Filter to one side: `Up` or `Down`. Omit to receive both, interleaved.
fromrequired	ISO 8601	Start of the window. Required.
torequired	ISO 8601	End of the window. Required.
limit	integer	Page size, max 5,000. Defaults to 1,000.
cursor	string	Cursor from the previous page.

Note

Order books are large. For windows over a day or so, prefer bulk Parquet downloads — same data, no pagination, free egress.

Light response

200 OK · tier=light

{
  "tier": "light",
  "data": [
    {
      "ts_us": 1747776000123456,
      "outcome": "Up",
      "bid_price": 0.62,
      "bid_size":  3210.4,
      "ask_price": 0.63,
      "ask_size":  1880.0
    }
  ],
  "next_cursor": "eyJ0cyI6..."
}

Full response

L25 snapshots include 25 price/size pairs for each side. Levels are sorted by price (bids descending, asks ascending) and may include gaps — missing levels mean the book was thinner than 25 deep at that tick.

200 OK · tier=full

{
  "tier": "full",
  "data": [
    {
      "ts_us": 1747776000123456,
      "outcome": "Up",
      "bid_price": [0.62, 0.61, 0.60, ...],
      "bid_size":  [3210.4, 1240.0, 880.0, ...],
      "ask_price": [0.63, 0.64, 0.65, ...],
      "ask_size":  [1880.0, 950.0, 600.0, ...]
    }
  ],
  "next_cursor": "eyJ0cyI6..."
}