Data vendorsAPIfree
polymarketdata.co: what it does, what it costs, where it stops
Last checked 2026-09-08
polymarketdata.co is a commercial historical data service for Polymarket. It stores minute-level price series, market metrics and L2 order book snapshots from August 2025 onward and serves them through a REST API, a Python SDK, custom exports and bulk S3 dumps. The site cites 19B+ rows and 1M+ unique markets.
It exists because Polymarket's public API returns live state, and this service's own FAQ makes that the pitch: no historical endpoint on the venue side, full time series here. Quant researchers and backtesters are the audience.
What it does
The data model is series, events and markets with historical market state, resolution outcomes and metadata. Time series run at one-minute resolution on paid plans and ten-minute resolution on the free plan. Order book history stores bid and ask depth rather than the last snapshot only.
Delivery options are the REST API with an API key, a Python SDK, recurring exports, and S3 dumps in Parquet, CSV or JSON on a one-time or scheduled basis. Resolved markets are queryable, which the site contrasts with the public API.
- 19B+ rows, 1M+ unique markets, 1-minute resolution (homepage figures).
- Order book snapshots begin August 2025.
- Topic filters (crypto, politics and so on) on every plan.
- The site states it is independent and not affiliated with Polymarket.
Pricing
Free: $0, 10 requests per minute, 10-minute time series, last month of data, no historical order books. Trader: $60 per month, 100 requests per minute, 1-minute series, last month of data, historical order books. Pro: $120 per month, 500 requests per minute, last 3 months of history. Ultra: $360 per month, 2,000 requests per minute, unlimited historical data.
Enterprise covers full data dumps, custom feeds and S3 exports, priced by contacting the team.
Venues and data
Polymarket only. There is no Kalshi coverage, so cross-venue backtests need a second source such as DepthFeed or Jon Becker's dataset.
The history floor is August 2025 for order books. Anything earlier comes from on-chain fills, which is what the free datasets in this category provide.
Where it falls short
The Free and Trader plans only reach back one month, so any real backtest starts at Pro ($120 per month) or Ultra. The documentation page renders client-side and could not be read without a browser during this check, so endpoint details and the Python package name are unverified here.
It is a data service. Finding a mispriced market in its order book history does not place a trade; that means the Polymarket interface, the official SDK, or a cross-venue terminal such as Kairos.
Who should use it
Backtesters who need Polymarket order book depth at minute resolution and are willing to pay $120 or more per month for history. Academic users are named on the homepage as a customer group.
Hobbyists checking price paths for a handful of markets can start on the free tier and stay there.
Questions about polymarketdata.co
How much does polymarketdata.co cost?
Free at 10 requests per minute with 10-minute data and one month of history. Paid plans are $60 (Trader), $120 (Pro) and $360 (Ultra) per month; Ultra has unlimited history and 2,000 requests per minute.
Does polymarketdata.co have Kalshi data?
No. It covers Polymarket only.
How far back does polymarketdata.co go?
The site says price history, market metrics and L2 order book snapshots are stored from August 2025 onward.
Is polymarketdata.co affiliated with Polymarket?
No. The footer states it is an independent project not affiliated with, endorsed by or sponsored by Polymarket.
Official APIs for building. One book for trading.
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