Last updated: April 2026
Cross-platform prediction market data. One API.
We’re building a unified API for Kalshi, Polymarket, and more — normalized market slugs, real-time prices, arbitrage signals, and state-by-state regulatory data. All editorially curated, not scraped.
What We’re Building
Platform-Neutral
Kalshi + Polymarket are core targets. No platform owns us. The goal is normalized data across major exchanges in one schema. Browse our platform directory to see the ecosystem we track.
Editorial Quality
Curated, not scraped. Cross-platform market matching with confidence scores. We flag mismatches so your data is clean.
Real-Time Signals
Arbitrage opportunities, volume spikes, and whale activity. Not just data — actionable intelligence. See it in action on our live activity dashboard.
Planned Endpoints
PREVIEW/api/v1/marketsList markets with cross-platform prices
/api/v1/markets/:slugSingle market — all platforms, spread, confidence
/api/v1/arbLive arbitrage opportunities
/api/v1/movers24h volume movers, cross-platform
/api/v1/regulatory-statusState-by-state legality matrix (all platforms)
/api/v1/markets/:slug/history30-day price history
Endpoints and parameters are subject to change before launch. This is a preview of the planned API structure.
Who It’s For
Journalists & Researchers
Citation-ready data with source attribution. Cross-platform prices in one call. Visit our media resources for attribution guidelines and press access.
Developers & Data Scientists
Normalized schema across platforms. Historical price data. Build dashboards, alerts, and analysis tools.
Traders & Analysts
Real-time arbitrage detection. Volume spike alerts. Cross-platform spread analysis. Compare trading costs with our fee comparison guide.
Content Creators
Embed live prediction market data in your content. Automated market summaries and trend reports.
Data Sources
Built on official platform APIs where available — not just web scraping. We plan to aggregate, normalize, and editorially curate data from major prediction market platforms.
Kalshi Trade API v2
REST + WebSocket. Well-documented, production-ready. Full orderbook access, market data, and trade execution. This API is also used by broker integrations and partner apps.
Polymarket Gamma API + CLOB
REST API for market data via Gamma. Central Limit Order Book (CLOB) for trading. On-chain settlement on Polygon. Comprehensive documentation for both data consumption and trade execution.
ForecastEx (via Interactive Brokers API)
Access ForecastEx prediction markets through IBKR's established Trader Workstation (TWS) API. Same API used for stocks, options, and futures. Requires an IBKR brokerage account.
Crypto.com CDNA
API access for the Crypto.com Derivatives North America exchange. Powers multiple consumer apps (OG Predictions, Fanatics Markets, Underdog). Documentation available for data and market access.
PredictionMarkets.us is an independent aggregator with no platform affiliations.
Related Reading
Compare every major prediction market platform side by side.
API / Geoblock Access ChecksSeparate public reads, authenticated CLOB calls, and geoblock diagnostics before building.
Platform Architecture MapUnderstand exchanges, wrappers, routers, and intelligence layers before choosing an integration path.
Live Market ActivityReal-time movers, volume trends, and whale activity across Kalshi, Polymarket, and PredictIt.
Fee Comparison GuideUnderstand trading costs across Kalshi, Polymarket, and more.
Market Insights & AnalysisDeep dives, trend analysis, and editorial commentary on prediction markets.
Journalism Tools & APIInteractive API explorer, embeddable widgets, and data tools for reporters.
Press & Media ResourcesAttribution guidelines, data access, and press contact information.
Getting Started GuideNew to prediction markets? Start here for a complete overview.