v56

latestOpenAPI 3.0.0raw.githubusercontent.com2026-07-215245616.9 KB

Fetch Order Book

Fetch the order book (bids/asks) for a specific outcome. Supports live and historical queries. For historical data, pass since to get a single snapshot, or since + until to get an array of fully reconstructed L2 books from the archive. Range queries return up to limit snapshots (default 100, max 1000).

get/api/{exchange}/fetchOrderBook

Path parameters

exchange'polymarket' | 'kalshi' | 'kalshi-demo' | 'limitless' | 'probable' | 'baozi' | 'myriad' | 'opinion' | 'metaculus' | 'smarkets' | 'polymarket_us' | 'gemini-titan' | 'hyperliquid' | 'suibets' | 'rain' | 'hunch' | 'router' required

The prediction market exchange to target.

Query parameters

outcomeIdstring required
limitnumber
side'yes' | 'no'

Outcome side: 'yes' or 'no'. Required for exchanges like Limitless where the API returns a single orderbook per market.

outcomestring

Outcome alias: 'yes' or 'no', or an outcome token ID. When set, the first argument is treated as a market ID and this value selects which outcome's order book to fetch. Accepts the literal strings 'yes'/'no' (resolved via a market lookup) or a raw outcome token ID.

sincenumber

Unix timestamp (ms) — fetch a historical snapshot at or before this time, or the start of a range when combined with until (hosted API only).

untilnumber

Unix timestamp (ms) — end of a historical range. When combined with since, returns an array of reconstructed L2 OrderBook snapshots between since and until (hosted API only).

Response

Fetch Order Book response

successboolean

Example response

{
  "success": true
}