Prediction Markets API
Kalshi and Polymarket contract prices, the Betfair Exchange and ProphetX, alongside every Australian sportsbook — one schema, one byBookmaker object, keyed by bookmakerID.
Why combine prediction markets with sportsbook odds?
A prediction market price is a probability with very little margin in it. Next to a bookmaker's price on the same outcome it is the cleanest edge signal there is — and until now it lived in a different API with a different schema. SockOdds normalises the contract into the same oddID as the sportsbook market, so polymarket and sportsbet are two keys in the same object.
Covered prediction market platforms
| Platform | bookmakerID | Type | Events priced | Leagues |
|---|---|---|---|---|
| Betfair Exchange | betfairexchange | Betting exchange | 164 | AFL, AFLW, ATP, Bundesliga, Premier League, Ligue 1, IPL, Serie A, La Liga, MLB, MLS, NFL, NRLW, Rugby Union Internationals, Champions League, WTA |
| Kalshi | kalshi | Prediction market | 253 | ATP, Bundesliga, Premier League, Ligue 1, Serie A, La Liga, MLB, MLS, NFL, WTA |
| Polymarket | polymarket | Prediction market | 292 | ATP, Bundesliga, Premier League, Ligue 1, La Liga, MLB, MLS, NFL, WTA |
| ProphetX | prophetexchange | Betting exchange | 187 | Bundesliga, Premier League, Ligue 1, Serie A, La Liga, MLB, MLS, NFL |
What can you build with a prediction markets API?
Arbitrage and cross-market analysis tools
Scan a contract price against every book's price on the same outcome; see the prediction market arbitrage use case.
Research and forecasting platforms
Use exchange and contract prices as a low-margin probability benchmark for models.
Odds aggregators and comparison sites
Show Polymarket next to Sportsbet in the same row without a second integration.
Algorithmic trading systems
Diff contract prices against book prices every refresh and act on the divergence.
Sports media and content products
"The market thinks" widgets with a real market behind them.
AI and ML models
Fair-price labels for training, with fairOdds derived from exactly these sources.
Why SockOdds for prediction market data?
One API, every market type
Sportsbooks, exchanges and prediction markets in one response.
No blockchain complexity
Polymarket is a price in a JSON object, not an on-chain query.
Already normalised with sportsbook data
Same oddID, same envelope, same American string plus decimal.
Same refresh, same flags
Every ~2 minutes with available and lastUpdatedAt per entry.
Retained history
Finished events stay in the feed for backtesting.
Example request
curl "https://api.sockodds.com/v2/events/?leagueID=NFL&bookmakerID=polymarket,kalshi,sportsbet&oddID=points-home-game-ml-home&includeOpposingOdds=true&limit=1" \
-H "x-api-key: YOUR_API_KEY"Frequently asked questions
What is a prediction markets API?
A feed of contract prices from prediction markets, normalised so they can be compared with bookmaker odds. In SockOdds they are part of the same events feed.
Which prediction markets do you cover?
Betfair Exchange, Kalshi, Polymarket, ProphetX.
How often is the prediction data updated?
Every ~2 minutes, the same cadence as the sportsbooks.
Is there a free trial for the prediction market API?
Prediction-market prices are on Base and above; the free Lite plan covers the Australian books on AFL and NRL.
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