The prediction markets API
Kalshi and Polymarket in one surface — markets, price candles, order books, and the full public trade tape, linked to the sports events they settle on, one Bearer token away.
One call to the market.
Plain REST over HTTPS, keyset pagination, JSON out. The response below is real — event 1153626 is The Open Championship on Kalshi.
curl "https://api.stat-api.com/api/v1/kalshi/markets?event_id=1153626" \
-H "Authorization: Bearer YOUR_API_KEY"
# → { "markets": [ {
# "ticker": "KXPGAR3TOP5-THOC26-EELS",
# "title": "The Open Championship: Will Ernie Els
# finish top 5 in Round 3?",
# "status": "finalized",
# ... 22 fields per row
# } ], "next_from_id": ... }
The tape, not just the ticker.
The public trade tape
120M trade-tape rows across both venues — every public fill, not a sampled feed. Kalshi's exchange tape plus Polymarket's on-chain trades.
Candles & price histories
77M event-driven price candles on Kalshi plus OHLC candles, price histories, and token snapshots on Polymarket.
Linked to the games they settle on
Sports markets carry a competition link to the underlying game or tournament — join market prices to play-by-play, injuries, and results in one query.
Order books & settlement
Polymarket order-book snapshots and outcome tokens; Kalshi market statuses and on-exchange settlement results.
Prediction-market API questions, answered.
Is there a free prediction market API?
Yes — the stat-api free tier includes 50,000 records a month across every league and market, with no card required. Paid tiers start at $49/mo for 5M records.
Which prediction-market venues are covered?
Kalshi (exchange markets, candles, public tape, settlements) and Polymarket (on-chain markets, outcome tokens, order books, price histories, public tape) — 572K markets combined.
Can I join market prices to the actual games?
Yes — sports markets carry a competition link to the underlying game or tournament, so prices join directly to schedules, play-by-play, injuries, and final scores.
Can AI agents and assistants use it?
Yes — an MCP server at api.stat-api.com/mcp (catalog tools need no key), a full OpenAPI 3.1 spec, a public GraphQL schema, and llms.txt. Any MCP client — Claude, ChatGPT, or your own agent — can query market data directly.
Start with the free tier.
50,000 records a month, every league and market, no card. The Kalshi and Polymarket references have live, runnable examples for all 17 tables.