Where to get historical Kalshi and Polymarket data, and what each source has: order book history and depth, trade history, how you get the data, and what it costs.
Kalshi Eye wrote this page and sells one of the products in it. Everything about the others comes from their own websites and docs, read on October 24, 2026 and linked below; prices and coverage change, so check the source before you buy. If a line is wrong or out of date, tell us and we will fix it.
At a glance
| Source | Venues | Order book history | Trades | How you get it | Price |
|---|---|---|---|---|---|
| Kalshi Eye (this site) | Kalshi, Polymarket, Limitless, Chainlink prices | Kalshi from October 12, 2026; Polymarket and Limitless from October 15, 2026. Every level and every change (Full book); top ten levels each second and every top-of-book change (Research). | From the same dates | Daily Parquet downloads, S3 sync, REST API, Python client | Explorer free; Research $79/month; Full book $149/month; Institutional on request. Free plan: last 30 days of bars, trades, settlements and market lists. Sample files without an account. |
| Probalytics | Polymarket, Kalshi | Polymarket from November 2025, Kalshi from May 2026. Full-depth snapshots on every change. | Polymarket from November 2022, Kalshi from January 2022 | ClickHouse SQL, REST API, Parquet export, Python SDK | Starter $39/month (30 days, no book); Pro $129; Orderbook $249. 3-day free trial; 20-row sample. |
| TickFoundry | Polymarket, Kalshi, Hyperliquid | Polymarket from February 2026 (own capture since May 11, 2026), Kalshi since September 27, 2026. 10 or 25 levels. | Kalshi back to June 2021; Polymarket on-chain fills back to August 2023 | Parquet and CSV downloads, REST API, SFTP | $29, $49 (10 levels) or $99 (25 levels) a month per venue; one market-day from $2. 5 free market-days. |
| Oddpool | Kalshi, Polymarket | Kalshi order book snapshots and top of book from March 19, 2026 | Kalshi from March 19, 2026 | REST API; S3 dumps on Enterprise | Free, $30 and $100 a month, Enterprise. Its pricing page says it is no longer accepting new subscriptions. |
| Tardis.dev | Polymarket (and many crypto exchanges) | From May 25, 2026: incremental L2, top of book, and 5- and 25-level snapshots | From May 25, 2026 | CSV downloads and API | Paid API key. The first day of each month downloads free, without a key. |
| Dune | Polymarket, Kalshi, Hyperliquid | None | Trades, hourly candles, open interest, positions; refreshed about hourly. Kalshi fills and most cross-venue tables need Enterprise. | SQL on Dune | Public tables on Dune's free tier; gated tables on Enterprise |
| pmxt archive | Polymarket | Polymarket order book events from April 13, 2026 (v2 archive), one Parquet file per hour | Not listed | Public HTTPS downloads; the pmxt SDK reads it | Free |
| Kalshi API | Kalshi | Current book only | Historical trades and candlesticks | REST and WebSocket | Free |
| Polymarket API | Polymarket | Current book only | Price history down to 1-minute points; trades through the data API; fills on-chain | REST and WebSocket; Polygon | Free |
Which to use
- Kalshi trades or prices before October 2026: Kalshi's own API is free and has historical trades and candlesticks. Probalytics and TickFoundry sell the same history as files or SQL.
- Polymarket order books before October 2026: Probalytics (from November 2025), TickFoundry (February 2026), the free pmxt archive (April 2026) or Tardis.dev (May 2026).
- Kalshi order books before October 2026: Oddpool (from March 2026, though its pricing page says it is not taking new subscriptions), Probalytics (May 2026) or TickFoundry (September 27, 2026).
- SQL without downloading files: Probalytics (ClickHouse) for books and trades, Dune for trades, positions and on-chain activity.
- Every change at every level of Kalshi's book, with Polymarket, Limitless and Chainlink prices in the same daily Parquet layout: Kalshi Eye.
Where Kalshi Eye is weaker
- Short history. Recording started on October 12, 2026 for Kalshi and October 15, 2026 for the other venues. Several sources above go back further, and for trades much further.
- No hosted SQL. You download files and query them yourself, with DuckDB or anything else that reads Parquet.
- No Hyperliquid, and no Polymarket outcome dataset yet: Polymarket resolutions come from its API.
- No Polymarket top-of-book file. You rebuild it from the L2 tape (how).
Where it is strong
- The whole Kalshi book. Every level of the YES and NO books and every change to them, not a fixed number of levels or periodic snapshots, with a full snapshot opening each day's file.
- A public record of gaps. Every hour the recorder missed is in the incidents file and on Data coverage, so a backtest can leave it out.
- Four venues on one plan, in one file layout, with a manifest of row counts and SHA-256 checksums for every day.
- Free to start. Sample files of every dataset with no account, and a free plan with the last 30 days of minute bars, trades, settlements and market lists.
Next
- Data by venue: what the archive holds for each venue.
- Pricing: plans, yearly prices and the license.
- How to backtest Kalshi markets