Prediction Market Odds API | 💵$2/1K

Get a live prediction-market odds feed from Polymarket, Kalshi, and Manifold in one normalized API — starting with a ~$0.052 quick run. The default returns 25 open Polymarket markets with no proxy or technical setup.

Most prediction-market APIs use different field names and data shapes. Prediction Market Odds API normalizes all three sources into one consistent schema — implied probability, favorite outcome, volume, liquidity, and resolution dates — ready for research, dashboards, journalism, bots, newsletters, or information-finance content.

✅ What you get / ❌ what this isn't

This Actor gives you	This Actor is not
Live markets from Polymarket, Kalshi, and Manifold in one unified schema	Not trading or betting advice
Implied probability, outcome prices, favorite outcome per market	Not a way to place trades or move funds
Volume and liquidity, with an explicit unit per platform	Not affiliated with Polymarket, Kalshi, or Manifold
Per-platform roll-up: market count, total volume, top markets	Not a full historical tick/orderbook archive
Reliable official-API reads (no anti-bot, no proxy needed)	Not a guarantee a specific market exists at run time

🔎 Why use Prediction Market Odds API

• Compare odds for the same event across multiple prediction markets.
• Track politics, sports, crypto, and economic markets in one dataset.
• Power a dashboard, newsletter, or bot with live implied probabilities.
• Research market sentiment and volume on a topic with a keyword filter.
• Feed normalized market rows into spreadsheets, a warehouse, or an LLM pipeline.

🗂️ What data you get

Field	Type	Description
platform	string	polymarket, kalshi, or manifold
question	string	The market question
category	string	Market category when the platform exposes one
outcomes	array	Outcome labels
outcomePrices	array	Price per outcome, 0-1 (implied probability)
yesProbability	number	Implied probability of the Yes/primary outcome (binary markets)
favoriteOutcome, favoriteProbability	string, number	Highest-priced outcome and its probability
volume, volumeUnit	number, string	Traded volume and its unit (USD / contracts / mana)
liquidity, openInterest	number	Platform-native liquidity; open interest (Kalshi)
status	string	open, closed, resolved, etc.
startDate, endDate	string	Market open and close/resolution dates
url	string	Link to the market

Plus a per-platform summary row: market count, total volume, markets with a price, and the top markets by volume.

👥 Who it's for

• Traders and quant hobbyists comparing odds across venues.
• Journalists and researchers covering prediction markets.
• Dashboard, newsletter, and bot builders.
• Sports, politics, and crypto analysts tracking sentiment.
• Data teams building normalized prediction-market datasets.

Example tasks

• Scrape Polymarket election odds
• Track crypto prediction markets
• Compare odds across Polymarket, Kalshi and Manifold

⚙️ How to scrape prediction markets

1. Choose a platform; Polymarket is selected for the quick-start run.
2. Optionally add a topic such as election, bitcoin, fed, or AI.
3. Keep Open markets selected for current odds.
4. Choose how many markets to return per platform; start with 25.
5. Click Start.
6. Open the dataset view for Markets or Platform summaries.
7. Export JSON, CSV, Excel, HTML, RSS, or XML, or call the Actor through the Apify API.

📥 Input

{
  "platforms": ["polymarket"],
  "status": "open",
  "keyword": "",
  "maxMarketsPerPlatform": 25
}

📤 Output

{
  "recordType": "market",
  "platform": "polymarket",
  "question": "Will JD Vance win the 2028 US Presidential Election?",
  "outcomes": ["Yes", "No"],
  "outcomePrices": [0.1925, 0.8075],
  "yesProbability": 0.1925,
  "favoriteOutcome": "No",
  "favoriteProbability": 0.8075,
  "volume": 14374508.43,
  "volumeUnit": "USD",
  "liquidity": 510789.8,
  "status": "open",
  "endDate": "2028-11-07T00:00:00Z",
  "url": "https://polymarket.com/event/will-jd-vance-win-the-2028-us-presidential-election"
}

💵 How much does it cost?

Each market row or platform summary is one paid result. The Free-plan price is $2.00 per 1,000 results, with discounts on higher Apify plans.

• Quick-start: 25 markets + 1 Polymarket summary ≈ $0.052.
• All three platforms with 25 markets each: up to 78 rows ≈ $0.156.
• 1,000 market results cost approximately $2.00.
• Failed platforms and the run-level summary are stored separately and are not charged dataset rows.

Platform summaries are useful results, not technical run summaries: each contains market count, total volume, priced-market coverage, and the top markets by volume.

🔁 Run it on the Apify platform

Schedule recurring odds refreshes, call it from the Apify API, export to CSV/JSON/Excel, or connect the dataset to Make, Zapier, webhooks, a warehouse, or an LLM pipeline.

⚠️ Limits and caveats

• This Actor reads the public APIs of Polymarket, Kalshi, and Manifold. It is not affiliated with them and provides no trading advice.
• Volume units differ by platform and are not directly comparable: Polymarket is USD, Kalshi is contract count, Manifold is mana (play-money). The volumeUnit field on every row makes the unit explicit.
• Manifold multiple-choice markets do not have a single Yes probability, so yesProbability is null for them; binary markets are fully priced.
• Kalshi data is read from its events feed (real, categorized markets) rather than the raw markets feed, which is dominated by auto-generated low-volume combinations.
• Markets are a live snapshot at run time; this Actor is not a full historical orderbook archive.

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❓ FAQ

Which markets does it return by default?

Open markets across all three platforms, ordered by popularity/volume where the platform supports it. Use the keyword filter to narrow to a topic.

How is implied probability calculated?

For binary markets, the outcome price (0-1) is the implied probability. Kalshi uses the last traded price (or the mid of the yes bid/ask when there is no last trade). Polymarket and Manifold expose the probability directly.

Can I compare the same event across platforms?

Yes. Run all three platforms with a shared keyword, such as a candidate or team name, then compare yesProbability and the source URL for each returned market. Event matching across platforms is not automatic.

Does it need a proxy?

No. These are public official APIs that work without a proxy. Enable Apify Proxy only on very large runs if you hit IP rate limits.

🛠️ Support

For bugs or missing fields, open an Actor issue with the run URL, the platform, and the field or behavior you expected.

⭐ Rate this Actor

If this Actor saved you time, please take 30 seconds to leave a review on the Reviews tab of Prediction Markets Scraper - Polymarket, Kalshi & Manifold - reviews are the main trust signal other users see, and they directly decide which features get built next. If something is broken or a field is missing, please open an issue first - we typically respond within a day and would love the chance to fix it before you rate.