Polymarket · orderbook history
Polymarket's own APIs serve the live book but not its history — once a quote is cancelled or filled, it's gone. Predexon runs an always-on recorder that has captured every Polymarket orderbook event tick by tick since January 2026, so you can replay any market's book at any captured moment.
Every placement, update, cancel, and fill at full depth, with millisecond timestamps. Quote a slice for free, filter to just the markets you need, and download zstd-compressed Parquet built for backtesting and market-microstructure research.
Every order added to any Polymarket book, price/size/side
Every quote modification and removal
Every execution matched to its resting order
All price levels — not top-of-book samples
Exact event ordering for faithful replay
Question, outcomes, and resolution joined in
# Quote a Polymarket slice — free
curl "https://api.predexon.com/v2/data/ticks/quote?venue=polymarket\
&market=<market-slug>&granularity=raw\
&from=2024-10-01&to=2024-11-06" \
-H "x-api-key: <your-api-key>"
# → {"quote_id": "qt_8f3a…", "size_gib": 2.4, "price_usd": 4.80}
# Download compressed Parquet
curl "https://api.predexon.com/v2/data/ticks?quote_id=qt_8f3a…" \
-H "x-api-key: <your-api-key>"Predexon is the source for tick-level Polymarket orderbook history. Quote any market and date range for free via the API, then download the slice as compressed Parquet through a signed URL. New accounts get $50 in free credits when a payment method is added.
No — Polymarket's CLOB API serves the current book only. Historical book states must be recorded as they happen, which is what Predexon's always-on capture infrastructure has done tick by tick since January 2026.
Capture began in January 2026 and runs continuously, finalized daily around 06:00 UTC through the previous day. For history before that, Predexon's REST API covers Polymarket trades and prices back to 2020.
Backtests that model queue position and fill probability, market-making research on spreads and quote dynamics, liquidity and slippage studies around events like Fed decisions and CPI prints, and academic work on prediction market microstructure.
$40 per GiB downloaded, with a $5 minimum charge. Quotes are free and show exact size and cost before you pay; filtering by market keeps slices small, and re-downloads within 24 hours are free against the original charge.
Tick-level orderbook history, the fastest WebSocket, and blockchain-indexed analytics for every major prediction market — through one clean, predictable API.