# PolyOrderbooks

Recorded L2 books for Polymarket crypto markets, priced by how far back you may look.

*https://predictionmarkets.tools/tools/polyorderbooks · Prediction Market Data APIs*

## Facts

### At a glance

| Field | Value |
| --- | --- |
| Vendor | PolyOrderbooks |
| Category | Prediction Market Data APIs |
| Job | historical |
| Website | https://polyorderbooks.com |
| Pricing model | subscription |
| Free tier | true |
| Open source | false |
| Licence | none |
| Self-hosted | false |
| Tested hands-on | false |
| Last updated | 2026-09-20 |

### Pricing

| Tier | USD | Period |
| --- | --- | --- |
| Starter | 0 USD | — |
| 30-day window | 19 USD | — |
| 60-day window | 29 USD | — |
| 90-day window | 39 USD | — |
| 120-day window | 49 USD | — |
| Backtest AI | 29 USD | — |

### Availability

| Field | Value |
| --- | --- |
| Jurisdictions | global |
| Open to US persons | true |
| KYC required | false |

### Markets

| Field | Value |
| --- | --- |
| Subjects | crypto |
| Settlement | crypto |
| Resolved by | none |

### Economics

| Field | Value |
| --- | --- |
| Taker fee | none |
| Maker fee | none |
| Liquidity model | clob |
| Platforms | web, library |
| AI features | research |

### Interfaces

| Field | Value |
| --- | --- |
| API | true |
| WebSocket | false |
| Scripting | none |
| Python | true |
| MCP server | true |
| Export | json |

### Capabilities

Yes: order_book, backtesting

No: charting, screening, automation, live_trading, paper_trading, portfolio_tracking, calibration_scoring, cross_venue, alerts, news, tax_reporting

*Verified: pricing 2026-09-20; availability 2026-09-20; markets 2026-09-20; capabilities 2026-09-20.*

## What it is

An archive of Polymarket's order book for one slice of the venue: crypto markets, captured off
the CLOB WebSocket feed and served back as bucketed history over REST. It is a live product with
a live API — `api.polyorderbooks.com` answered this machine on 20 September 2026, returning
`{"error":"unauthorized"}` with HTTP 401 to a keyless call and `"Invalid API key."` to a wrong
one, which is the pair of answers a running gateway gives.

The read surface is small. `GET /v1/series`, `/v1/events`, `/v1/markets` and `/v1/tags` discover;
`GET /v1/markets/{id_or_slug}` resolves a market to its outcome token ids; then
`/markets/{id}/prices`, `/markets/{id}/metrics` and `/markets/{id}/books` return the history,
with `/tokens/{id}/prices` and `/tokens/{id}/books` for the single-token form. `GET /v1/usage`
echoes your plan's limits. Every one of them takes `start_ts`, an **exclusive** `end_ts` and a
`resolution` from `1s` through `1d`, and pages with opaque cursors at a default of 100 rows and a
maximum of 200.

Two design statements from the documentation are worth carrying into any code you write against
it. **Reads are local**: discovery and history query the vendor's own store and never call
Polymarket live, so a market that was never captured does not appear. And captures are **sparse
by design, materialised uniform**: the collector writes a row when a token's book changes, and
the API fills the gaps by last-value carry so that every bucket you asked for comes back. A
1-second series is therefore a grid over an event stream, not a proof that the book was read on
each of those seconds.

Beside the API sits **Backtest AI**, a natural-language strategy replay: you describe a crypto
up-or-down rule in a sentence, it compiles that into a specification, replays it over resolved
markets against the recorded ladders, and returns net P&L, win rate, profit factor, maximum
drawdown, an equity curve and a written summary. The response carries the compiled `strategy`
block, which is the part that makes a run checkable rather than a number to take on trust.

## Availability

No geographic gate and no identity check. The terms of service dated 23 August 2026 condition
eligibility only on being able to form a binding contract and meeting the age requirement of your
own jurisdiction; there is no US clause, no restricted-country list and no KYC step. Access is an
email-verified account and a key beginning `pob_`. Paid plans take cards or, per the vendor,
300-odd cryptocurrencies.

What there is instead of a geographic gate is silence about who you are contracting with. The
terms name no company, no country and no address: governing law is "the laws applicable where
PolyOrderbooks principally operates". They also still describe paid plans as renewing "when
checkout is live", a month after the pricing page began offering checkout. Read section 15 before
an invoice matters to you.

Nothing here is permission to trade anything. Reading a recorded Polymarket book is not access to
Polymarket — that question is answered on [polymarket](https://predictionmarkets.tools/tools/polymarket), and the terms are
explicit that your licence covers the delivery of the service and not ownership of the underlying
exchange data.

## Pricing

One free plan and one paid axis. **Starter is $0, needs no card, and is not throttled on
resolution** — it can request 1-second buckets exactly like every paid plan. It gets three days of
lookback, 60 requests a minute and 1,000 a day.

Paid plans are the same product with a longer rolling window: $19 a month for 30 days, $29 for
60, $39 for 90, $49 for 120, all at 300 requests a minute and 50,000 a day. Two speed packages
sit on top — Fast at $19 a month for 1,000 a minute and 120,000 a day, Heavy at $39 for 2,500 and
300,000 — and those numbers are in the documentation rather than on the pricing page, which
advertises the add-ons without saying what they buy. Backtest AI is $19 a month as an add-on to a
data plan, or $29 standalone with its own 30-day window. Enterprise is a conversation: S3 bulk
drops in Parquet, CSV or JSON, custom limits and an SLA.

Two things the price table does not say out loud. The window is a **rolling lookback from now**,
not a slice you choose: a query whose `start_ts` predates it returns HTTP 403 naming the earliest
timestamp allowed. And 120 days is the deepest history anyone can buy without talking to sales,
which puts a ceiling on any study that wants a year.

Rate limits are per minute on a rolling window and per day in UTC, resetting at midnight, with
429 and a `Retry-After` header in seconds.

## Markets & resolution

**Polymarket crypto markets only.** The pricing FAQ and the documentation both say it in the same
words: other categories are not in the archive. That is the single fact that decides whether this
product is for you — there is no politics book here, no sports, no second venue, and no plan that
adds one.

PolyOrderbooks resolves nothing, so `resolution_source` is null. Settlement belongs to Polymarket
and is described on [polymarket-clob-api](https://predictionmarkets.tools/tools/polymarket-clob-api). What the archive keeps
after an event settles is the market and its winner, which is what makes a replay over resolved
markets possible at all.

The site's own counter reported 819,500 markets indexed, 779.7M order book snapshots, 144.6M
price snapshots and 332.8M metrics snapshots on 20 September 2026.

Separately from the API, the vendor publishes a **citable dataset** rather than a sample: 897,192
one-second L2 snapshots across 805 resolved Polymarket up-or-down markets at three contract
lengths — 5 minutes, 15 minutes and 4 hours — over eight coins, captured 21 to 24 August 2026,
deposited on Zenodo on 24 August 2026 under CC BY 4.0 with a DataCite DOI, and mirrored as
Parquet on Hugging Face and CSV on Kaggle. Its README is unusually candid about the capture: the
Polymarket delta feed carries roughly 24,000 events a second with no sequence numbers, so dropped
messages cannot be detected from the stream, and the collector re-reads the full book over REST
every 60 seconds to bound the drift. It also publishes its own error rates rather than cleaning
them — 16.9% of five-minute rows have one side of the book empty, rising to 76.2% in the final
minute, and 1.5% to 3.24% of rows are crossed and flagged rather than removed.

## Integrations

Plain JSON over HTTPS with `X-API-Key: pob_…` or the same value as a bearer token; dashboard
session tokens are explicitly not accepted on data routes. There is no WebSocket and no live
feed of any kind — this is history and only history.

An official Python client is on PyPI as `polyorderbooks`, MIT by its metadata, version 0.2.0
uploaded 24 August 2026, one dependency (`httpx`) and Python 3.9 or newer. An official MCP server
is on npm as `@polyorderbooks/mcp-server`, MIT, version 0.2.3 published 25 August 2026, exposing
the archive as tools in Claude and Cursor. Backtest AI has its own route, `POST /v1/ai/backtest`,
available on any authenticated plan.

The documentation publishes an OpenAPI description and an `llms.txt` index, and the endpoint
pages carry a request playground once you paste a key.

## Limitations

- **Crypto only, one venue only.** No politics, no sports, no macro, no Kalshi, no Limitless. If
  the question is anything but a crypto up-or-down market on Polymarket, this product has no
  answer at any price.
- **120 days is the self-serve ceiling.** Longer history exists only as an Enterprise contract,
  and the free tier's three days is short enough that validating the schema is most of what it is
  for.
- **Nothing is keyless.** Every `/v1` route requires an API key, so there is no way to see a real
  response before creating an account. Both keyless and wrong-key calls returned 401 on
  20 September 2026, which proves the gateway is up and proves nothing about the data behind it.
- **"Snapshotted every second" is a bucket, not a read.** Capture is on book change with a
  60-second REST reconcile; the uniform 1-second series is produced by last-value carry. The
  published dataset says so plainly and quantifies the drift; the marketing page does not.
- **The advertised source repositories do not exist.** The documentation, the `llms.txt`, the
  PyPI project links and the npm `repository` field all point at `github.com/polyorderbooks/…`,
  and on 20 September 2026 that account returns 404 — so the "runnable examples on GitHub" and the
  SDK source are not there to read.
- **No WebSocket, no alerts, no live prices.** Anything happening now comes from Polymarket
  itself.
- **200 rows a page.** At 1-second resolution that is 200 seconds per request, so a single day of
  one market's book is 432 calls — comfortable inside the paid daily cap, and a third of the free
  plan's entire day.
- **A counterparty you cannot name.** No company, no jurisdiction and no address anywhere in the
  terms, on a product whose value is that its archive keeps existing.

## Alternatives

[DepthFeed](https://predictionmarkets.tools/tools/depthfeed) is the closest thing to a direct competitor and differs on three
axes that matter: it covers Polymarket, Kalshi and Limitless rather than one venue, it serves the
raw tick tape of every book change on its top plan rather than materialised buckets, and it has a
keyless demo endpoint you can call before signing up. It costs more — $29, $99 and $249 against
$19 to $49 — and it does not publish a dataset with a DOI.

For live books rather than recorded ones, the [Polymarket CLOB API](https://predictionmarkets.tools/tools/polymarket-clob-api)
is keyless, free and authoritative, and keeps no history worth the name; the
[Gamma API](https://predictionmarkets.tools/tools/polymarket-gamma-api) is the catalogue beside it.

For breadth rather than depth — many venues, many subjects, no ladders — [Adjacent](https://predictionmarkets.tools/tools/adjacent)
and [FinFeedAPI](https://predictionmarkets.tools/tools/finfeedapi) sell a normalised cross-venue feed, and neither is free.

If what you actually need is a citable file rather than a subscription, take the Zenodo deposit
and stop: it is CC BY 4.0, 43 MB, carries a persistent identifier and needs no account.

## FAQ

### Is PolyOrderbooks an API, a dashboard, or both?

An API, with a dashboard attached to it rather than the other way round. The vendor's own FAQ answers "Do I need a dashboard?" with no - the dashboard issues keys and shows usage, and integrations call the REST API directly. The one screen that does real work is the Backtest AI workspace.

### Is there a free tier?

Yes, and it is not crippled on resolution. The Starter plan costs nothing, needs no card, and can request 1-second buckets exactly like the paid plans. What it buys you is three days of lookback, 60 requests a minute and 1,000 a day, and one AI backtest a month. You still need an account and a key - no endpoint answers without one.

### How far back does the history go?

As far as your plan's rolling lookback and no further. Three days on Starter, then 30, 60, 90 or 120 days by price, with anything deeper sold as Enterprise. A start_ts older than your window returns HTTP 403 naming the earliest timestamp you may ask for, so this is a hard gate rather than a thin result.

### What markets does it cover?

Polymarket crypto markets, and nothing else. Both the pricing FAQ and the documentation say so in the same words - other categories are not in the archive. There are no politics, sports or macro books here, and no second venue.

### Is it affiliated with Polymarket?

No. The footer, the terms of service and the published dataset all state that PolyOrderbooks is an independent product, not affiliated with or endorsed by Polymarket, and that market data originates from public exchange sources.

## Background

- [Where weather data comes from and what you may do with it](https://predictionmarkets.tools/guides/where-weather-data-comes-from.md) — Observations, model output and archives are three products with three licences. The forecast is the cheap half; a clean observation history is not.

- [Why the same contract costs two different prices on two venues](https://predictionmarkets.tools/guides/why-the-same-contract-costs-two-prices.md) — Two venues quoting one outcome are quoting two contracts. What the gap between the prices is made of - rules, fallbacks, fees, collateral, exits, eligibility.
- [What a trade actually costs on a prediction market](https://predictionmarkets.tools/guides/what-a-trade-actually-costs.md) — Venues publish trading fees in four incompatible units, so 3.00% on one can be cheaper than 1.75% on another. How to convert them, and what else takes a cut.

## Also worth comparing

- [DepthFeed](https://predictionmarkets.tools/tools/depthfeed.md) — The recorded bid-ask ladder for crypto up-or-down markets, which no venue keeps itself.
- [Predexon](https://predictionmarkets.tools/tools/predexon.md) — Tick-level book history as Parquet, billed by the gigabyte, plus a mempool-aware feed.
- [Futuur API](https://predictionmarkets.tools/tools/futuur-api.md) — One question, two order books — play money and real money, selected per request.
- [Limitless API](https://predictionmarkets.tools/tools/limitless-api.md) — REST and WebSocket for markets, books, candles and trading on Base.
- [Polymarket CLOB API](https://predictionmarkets.tools/tools/polymarket-clob-api.md) — Order books, prices and order placement on Polymarket's matching engine.
- [Polymarket Gamma API](https://predictionmarkets.tools/tools/polymarket-gamma-api.md) — Polymarket's read-only catalogue of events, markets, series and tags.