# Oddpool

Kalshi and Polymarket matched into one schema, with paid self-serve plans now closed.

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

## Facts

### At a glance

| Field | Value |
| --- | --- |
| Vendor | Oddpool |
| Category | Prediction Market Data APIs |
| Job | cross_venue_feed |
| Website | https://www.oddpool.com |
| Pricing model | subscription |
| Free tier | true |
| Open source | false |
| Licence | none |
| Self-hosted | false |
| Tested hands-on | false |
| Last updated | 2026-10-01 |

### Pricing

| Tier | USD | Period |
| --- | --- | --- |
| Free | 0 USD | — |
| Pro | 30 USD | — |
| Premium | 100 USD | — |
| Enterprise | on request | — |

### Availability

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

### Markets

| Field | Value |
| --- | --- |
| Subjects | politics, sports, macro, crypto, culture |
| Settlement | cash, crypto |
| Resolved by | none |

### Economics

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

### Interfaces

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

### Capabilities

Yes: charting, screening, order_book, paper_trading, cross_venue

No: backtesting, automation, live_trading, portfolio_tracking, calibration_scoring, alerts, news, tax_reporting

*Verified: pricing 2026-09-30; availability 2026-09-30; capabilities 2026-10-01.*

## What it is

A cross-venue data layer over Kalshi and Polymarket, sold two ways that are now far apart. The
public half is a website of free dashboards that price the same event on both venues side by side,
plus a metered REST and WebSocket API. The half the home page now leads with is institutional: a
tick-level order-book archive and a reference-data registry that gives the same outcome on Kalshi,
Polymarket and Polymarket US one canonical id, delivered by REST, WebSocket or daily Parquet files
to your own bucket, priced on a call.

The API is conventional for this category. Search runs across both venues by text or by series id
(`KXBTC15M` on Kalshi, `btc-up-or-down-15m` on Polymarket); historical endpoints return full
order-book snapshots, a top-of-book time series and the trade tape per venue; OHLCV bars come in
6-hour, daily, weekly and monthly intervals for up to 50 markets a call. The WebSocket is the more
interesting design: channels are addressed by event rather than by venue ticker —
`dist:fomc-2026-04-29` rather than a Kalshi ticker and a Polymarket token — and both venues arrive
on the same channel tagged by a `venue` field. Two feeds are documented, a macro feed (FOMC, CPI,
payrolls, GDP, unemployment) and a crypto feed that attaches a Binance spot and futures reference
price to every BTC and ETH message.

On the website there are dashboards for over 750 events, an arbitrage scanner and a price-spread
view across Kalshi, Polymarket and Opinion, a whale-trade tracker, paper trading with 10,000
virtual dollars against live prices, and Oddbot, a chat assistant launched on 6 May 2026 that
answers from the same data.

The publisher is Oddpool, Inc., which its privacy policy names and whose terms are governed by
Delaware law. The home page carries a Y Combinator logo under "Backed by".

## Availability

An account and an API key, with no identity check and no geographic restriction in the Terms of
Service or the privacy policy we read on 30 September 2026. Nothing here is a venue, so there is
nothing to deposit and no jurisdiction question about the data itself — only about whether you may
trade on what you read, which is the venue's question and sits on the [Kalshi](https://predictionmarkets.tools/tools/kalshi) and
[Polymarket](https://predictionmarkets.tools/tools/polymarket) cards.

The API is live and gated: an unauthenticated request to `api.oddpool.com/search/events` answered
`401` with "Authentication required (API key or signature)" on 30 September 2026.

**New paid subscriptions are closed.** On the same day the pricing page said "Oddpool is no longer
accepting new subscriptions. Existing subscriptions and free accounts continue as normal", and both
Pro and Premium were marked not available. The notice is absent from a Wayback capture of 10 June
2026 and present in one of 31 August 2026, so it went up somewhere in that window. A new reader
today can have the free tier or an enterprise conversation, and nothing between.

## Pricing

Four published tiers, two of them closed to new subscribers.

- **Free** — $0. The dashboards, search, historical data, paper trading and about 30 Oddbot chats a
  month. 1 request a second and 1,000 API requests a month as a hard cap, one key, one WebSocket
  connection limited to the `dist` channel for two events at a time.
- **Pro** — $30 a month, closed. 10 requests a second, 1 million a month, three connections on all
  channels for ten events, and the arbitrage, spread, volume and whale dashboards plus the whale API.
- **Premium** — $100 a month, closed. 25 requests a second, 5 million a month, ten connections and
  unlimited events, and the arbitrage and price-spread APIs.
- **Enterprise** — priced on a call. 500 requests a second, unlimited quota, tick-level
  microstructure data, S3 dumps, custom delivery and SLAs.

1,000 requests a month is roughly one request every 45 minutes. It is enough to evaluate the
schema and pull a handful of books, and not enough to poll anything; with the paid tiers shut, the
next step up from the free tier is a sales call.

Oddpool charges no trading fee because it executes nothing. Every fill is the venue's.

## Markets & resolution

Whatever Kalshi and Polymarket list — elections, sports, macro releases, crypto price windows and
awards. The home page claims search over more than 700,000 markets. Oddpool resolves and settles
nothing, so `resolution_source` is null, and settlement lists both types because the two venues do not
share one: Kalshi pays in dollars, Polymarket in pUSD on-chain.

The most useful sentence on the vendor's site is about exactly that. On a sample of 250 matched
events, the institutional page says only about a third were settlement-fungible across both venues;
the rest differed in the settlement window (a different deadline) or the settlement universe
(different bucket boundaries or candidate set). A price gap between two such listings is a
difference in contract terms before it is anything else, and the free dashboards and the arbitrage
scanner present them side by side. The reference-data product records that classification per
pair; it is enterprise-only, and every call to it without an institutional key returns 403.

History starts late. The documented API holds Kalshi from 19 March 2026 and Polymarket from 20
March 2026, published about an hour after the fact, and the vendor states that neither venue offers
a backfill — the archive exists only from the day Oddpool started recording.

## Integrations

REST at `api.oddpool.com` with the key in an `X-API-Key` header, a WebSocket at
`feeds.oddpool.com/ws` authenticated by a message after connecting, and cursor pagination on the
historical endpoints. `dist`, `book` and `trade` channels are change-driven, so a quiet channel is
silent, and a `snapshot` channel delivers full state every 60 seconds — on paid tiers only. The
enterprise tier adds daily Hive-partitioned Parquet for DuckDB, Polars, Spark or a Snowflake share.

No SDK in any language and no data MCP server. The documentation publishes an `llms.txt` index for
coding agents instead; the MCP entry on the docs site is the documentation host's own search
integration, not access to the data.

There is no alert channel either. The arbitrage landing page promises "instant alerts" and a
notification, but on 1 October 2026 no row of the pricing table, no changelog entry and no
documentation page described an email, push or Telegram notification, and the pricing FAQ presents
a Telegram alert as something you build yourself on Premium. The alerts flag is off for that
reason.

## Limitations

**The terms and the documentation disagree about what you may build.** The Terms of Service, last
updated 11 March 2026, say you may not use the Service for trading automation, and license all
data — arbitrage opportunities, spreads, whale trades, historical snapshots — for personal, internal
use only, with no redistribution or incorporation into another product. The documentation pitches
arbitrage bots that "execute automatically", copy trading off the whale feed and alert bots, and
the pricing page's own FAQ describes Premium as "built for automated strategies". Until the vendor reconciles
the two, the contract is the terms.

**The arbitrage endpoint is a trade instruction, not a measurement.** It returns "buy YES here,
buy NO there" with a per-contract net after fees, and its documentation describes the result as
profit locked in. What it models is the top 25 ask levels and each venue's fee schedule; what it
does not model, by its own note, is latency, partial fills or order minimums — and, from the
paragraph above, whether the two listings settle on the same terms at all. Resolution risk on the
two legs is the risk that remains.

**The retail product has stopped taking money.** The changelog's last entry is Oddbot on 6 May 2026
and the research page's last article is dated 28 May 2026; paid plans closed between June and
August. A free tier on a vendor that has turned toward institutional sales is a tier with no stated
commitment behind it.

**Oddbot is marketed as a research tool with an opinion.** The launch note says it will
"pressure-test a trade thesis" and "point at the cleanest market to express it". This card carries
`ai_features: research` because what it is documented to do is look up prices, history, whale flow
and spreads and cite them; the market-choosing line is the part to read with care. We have not used
it.

**Two venues.** Anyone who wants [Limitless](https://predictionmarkets.tools/tools/limitless), [Myriad](https://predictionmarkets.tools/tools/myriad) or
[Manifold](https://predictionmarkets.tools/tools/manifold) in the same schema is at the wrong
card, and Opinion appears only in the arbitrage scanner.

## Alternatives

[FinFeedAPI](https://predictionmarkets.tools/tools/finfeedapi) normalizes nine venues rather than two and sells requests with no
closed tiers, but has no WebSocket on this product. [Adjacent](https://predictionmarkets.tools/tools/adjacent) covers the same two
venues with indices and reference rates, and publishes a free delayed tier and paid plans you can
still buy. [Predexon](https://predictionmarkets.tools/tools/predexon) sells tick-level book history as Parquet by the gigabyte
across more venues, with an archive starting at almost the same point in March 2026.
[PMXT](https://predictionmarkets.tools/tools/pmxt) is open source and can be run on your own machine against the venues directly.
The venues' own feeds — the [Kalshi API](https://predictionmarkets.tools/tools/kalshi-api) and the
[Polymarket Gamma API](https://predictionmarkets.tools/tools/polymarket-gamma-api) — are free and deeper, at the cost of doing
the cross-venue matching yourself, which is the one thing Oddpool is actually selling.

## FAQ

### Can I still subscribe to Oddpool Pro or Premium?

No. On 30 September 2026 the pricing page said Oddpool is no longer accepting new subscriptions, marked both paid plans not available, and said existing subscriptions and free accounts continue as normal. The notice is absent from a Wayback capture of 10 June 2026 and present in one of 31 August 2026.

### What does the free Oddpool API include?

Search and historical order-book, top-of-book and trade endpoints for Kalshi and Polymarket, at 1 request a second and a hard cap of 1,000 requests a month, plus one WebSocket connection limited to the probability-distribution channel for two events. Whale, arbitrage and spread endpoints are paid.

### How far back does Oddpool's historical data go?

On the documented API, Kalshi from 19 March 2026 and Polymarket from 20 March 2026, available about an hour after the fact. The vendor says neither venue offers a historical backfill, so nothing earlier exists here at any price.

### Can I build a trading bot on the Oddpool API?

The documentation suggests it — arbitrage bots, copy trading, spread alerts — but the Terms of Service, last updated 11 March 2026, forbid using the Service for trading automation. Read the terms before building, or ask the vendor for a written exception.

### Which venues does Oddpool cover?

Kalshi and Polymarket across search, history, dashboards and the WebSocket. The arbitrage scanner also covers Opinion, and the enterprise reference-data product adds Polymarket US.

## Background

- [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.
- [Where a dashboard gets its data, and what it loses when that moves](https://predictionmarkets.tools/guides/where-a-dashboard-gets-its-data.md) — A venue API, an indexer or the chain itself. Which one a dashboard reads decides how far back its history goes and what vanishes when that source changes.

- [Why two dashboards show different volume for the same market](https://predictionmarkets.tools/guides/why-two-dashboards-disagree-on-volume.md) — Volume is several quantities under one name - contracts or dollars, one side or both, swaps or also mints and merges, and whose day. How to tell which.

## Also worth comparing

- [Adjacent](https://predictionmarkets.tools/tools/adjacent.md) — Prediction-market indices and reference rates, with Kalshi on the tier you can test.
- [Apify prediction-market scrapers](https://predictionmarkets.tools/tools/apify-prediction-market-scrapers.md) — A store of third-party actors that normalize Kalshi and Polymarket into one row shape.
- [Predictefy](https://predictionmarkets.tools/tools/predictefy.md) — Sixteen venues behind one verb family, priced in credits, with nothing readable for free.
- [FinFeedAPI Prediction Markets API](https://predictionmarkets.tools/tools/finfeedapi.md) — Nine event venues normalized into one REST schema, billed by usage credit.
- [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.