Event Probability API.
Real-money prediction markets as machine-readable probabilities.
Query elections, policy, macro, geopolitics, rates, energy, and crypto as structured event probability state instead of headlines. Kalshi and Polymarket normalized into one response, with gov/econ context, related markets, and a next-action graph an agent can follow without re-querying.
Charting the unknown — every probability is a position on the map.
What is an event probability API?
The market-implied chance of a real event, in a shape an agent can act on.
A news API returns articles. A market data API returns prices. An event probability API returns the same prices reframed as calibrated odds, alongside the related contracts, the venue identifiers, the macro and policy context, and a next-action graph the consumer can follow.
probabilityMarket-implied 0–1 probability for the event resolving Yes.
title / questionHuman-readable event question — "Will the Fed cut rates before 2027?"
venue + tickerKalshi ticker, Polymarket slug, or both when the event lists on both venues.
volume / liquidityRecent volume and liquidity hints so consumers can weight the probability.
contextGovernment bills, economic series, traditional market anchors when relevant.
related marketsSibling contracts on the same event family for fuller context.
nextActionsInspect, screen, monitor, and drill endpoints — a graph the agent can follow.
Why prediction markets are useful for event probabilities
Web search
Documents and snippets
No calibrated probability or liquidity context
News API
Headlines and articles
No market-implied odds; recency-mixed
Raw venue API
Prices and orderbooks
No cross-venue, no gov/econ context, no next-action graph
SimpleFunctions Event Probability API
Probability, context, related markets, and next actions
Probabilities should still be interpreted with liquidity and settlement context
Use cases for the Event Probability API
Anywhere an application needs a calibrated probability instead of a paragraph.
AI agents
Drop calibrated event probabilities into a system prompt or MCP tool. Reason from numbers, not narratives.
Macro dashboards
Augment Bloomberg-style panes with prediction-market probabilities for upcoming Fed actions, CPI prints, elections.
Policy monitoring
Track legislation status alongside the prediction market probability that the bill becomes law.
Risk monitoring
Wake on probability moves for recession, geopolitical conflict, or oil disruption thresholds.
Trading research
Use cross-venue probabilities and traditional market anchors to size theses or screen candidates.
Corporate planning
Incorporate election, regulatory, and macro probabilities into scenario planning and budgeting models.
API examples
Three endpoints, one response contract. Pick the surface that matches the event type.
FAQ
What is an event probability API?
An event probability API returns the market-implied probability of a real-world event, in a structured form an application or AI agent can read directly. SimpleFunctions returns the probability, the contracts, related markets, gov/econ context, and follow-up endpoints for the same event.
Where do the event probabilities come from?
Primarily from real-money prediction markets — Kalshi (CFTC-regulated) and Polymarket. SimpleFunctions normalizes both venues and adds context, related contracts, traditional market anchors, and next actions on top.
Are prediction market prices the same as probabilities?
They are market-implied probabilities, not guarantees. Liquidity, fees, settlement risk, and venue structure can affect interpretation, so SimpleFunctions returns context and liquidity hints alongside the price.
Does the event probability API cover both Kalshi and Polymarket?
Yes. Both venues are searched on every query and returned in normalized arrays. When the same event has contracts on both venues, the API surfaces both with their respective tickers, slugs, and prices.
Can I search the API in natural language?
Yes. /api/public/query handles broad event questions, /api/public/query-gov resolves bills and legislation through a Congress-data mirror, and /api/public/query-econ links FRED economic series to related markets.
Can I filter probabilities by topic?
Yes — through /api/agent/world?focus=energy,geo for topic-focused world state, or via /api/public/screen for indicator-based filtering of active markets.
How is this different from a news API?
A news API returns articles and headlines. An event probability API returns market-implied probabilities, related contracts, movement, and follow-up endpoints that an agent or app can act on. News tells you what happened; probabilities tell you what the market thinks happens next.
How is this different from a raw market data API?
Venue APIs (Kalshi, Polymarket) return raw prices and orderbooks. The Event Probability API returns the same prices plus normalized cross-venue identifiers, gov/econ context, related contracts, and a next-action graph that agents can follow without re-querying.
Can AI agents use the API directly?
Yes. Agents call /api/public/query for targeted questions, /api/agent/world for ambient context, and /api/agent/world/delta for incremental updates. No auth required for public endpoints.
Does SimpleFunctions execute trades?
SimpleFunctions exposes software workflows for intents, triggers, routing, and monitoring through the runtime layer, but it is not a broker, exchange, custodian, FCM, or investment adviser. Use the venues directly for actual order placement.
Related surfaces
World State API for AI Agents
Compact ambient probability state for agent context.
Prediction Market API
Full data and workflow surface for Kalshi, Polymarket, and agents.
Prediction Market Index
Market-wide volatility, geo risk, breadth, and activity.
Prediction Market Search API
Natural-language event search across venues and context.
Government Event API
Legislation, nominations, members, and prediction markets.
Economic Data API
FRED-backed economic series plus related prediction markets.
Prediction Market Screener
Filter active markets by indicators and microstructure.