Does Polymarket have a public API, and is it free?

Yes. Polymarket publishes its own API (REST, WebSocket, GraphQL). Reading public market data is free and needs no API key. Its rate limits and sign-in methods are in the table on this page.

Does Kalshi have a public API, and is it free?

Yes. Kalshi publishes its own API (REST, WebSocket, MCP). Reading public market data is free and needs no API key. Its rate limits and sign-in methods are in the table on this page.

Where can I get historical prediction market data?

42 of the APIs here offer historical data, but only 5 state an exact start date; the earliest is Probalytics, from 2 October 2020. Use the "Historical data" filter to see them all.

Which prediction market data providers have a free tier?

27 of the independent providers state a free tier or free use: 0xArchive, Adanos Software, Adjacent, Bravado, DepthFeed, KalshiSpy and 21 more. Limits differ; each row gives them.

How much does prediction market data cost?

The cheapest published plans range from $10 a month (outcometick) to $200 a month (Prediction Labs). What each plan includes differs, so compare the data and history columns too.

Which prediction market APIs work with AI agents?

24 offer an MCP server that AI assistants can call directly: Kalshi, Limitless, Hunch, 0xArchive, Adjacent, Bravado and 18 more.

Prediction market APIs compared

The markets' own APIs, the data providers built on top of them and the open-source clients, side by side: what data each one gives, how far back it goes, how it is delivered and what it costs. Every fact comes from the provider's own documentation, pricing page or repository, read on 6 November 2026.

markets with their own API: 26; markets with their own API
independent data providers: 42; independent data providers
with a free tier: 41; with a free tier
with historical data: 42; with historical data

MarketAny Polymarket 56 Kalshi 33 Limitless 10 Predict.fun 9 Opinion 8 Hyperliquid 5 Myriad 5 Manifold 4 Novig 4

NeedsAnything Free tier Historical data WebSocket MCP for AI agents Places orders Bulk files

14 APIs match. Show all

The markets' own APIs

Run by the exchange itself. Usually free to read, with a key or a wallet signature to trade. Open a row for sign-in, rate limits and links.

Official prediction market APIs
Market	Prices	Order books	Trades	History	Wallets	Trading	Delivery	Free	Paid from	Details
Kalshi	Prices: yes	Order books: yes	Trades: yes	History: yes	Wallets: yes	Trading: yes	RESTWebSocketMCP	Yes	–
Data Markets Prices Order books Trades Price history Wallets Resolutions Trading Delivery REST WebSocket MCP SDKs: Python, TypeScript Markets covered Kalshi Sign-in none for public REST and MCP market reads; API key with RSA-PSS or Ed25519 signature for authenticated API requests; OAuth for MCP account/alerts Free use Yes. Public REST market data without authentication. Basic account tier: 200 read tokens/second, 100 write tokens/second; most requests cost 10 tokens. API subscription price not published. Rate limits Predictions read/write token budgets per second: Basic 200/100; Advanced 300/300; Expert 600/600; Premier 1,200/1,200; Paragon 2,400/2,400; Prime 4,800/4,800; Prestige 12,000/9,600. Most requests cost 10 tokens. Basic/Advanced read and above-Basic write capacities are 3x refill; others 1x. Separate balance bucket 1 request/second Basic/Advanced, 5/second higher. Shared Predictions/Perps WebSocket connections: 200 Basic/Advanced/Expert, 500 Premier, 750 Paragon, 1,000 Prime/Prestige. Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026

Data providers

Independent services that collect, clean and resell market data, often across several exchanges and further back than the exchanges keep. Open a row for what each plan includes.

Prediction market data providers
Provider	Prices	Order books	Trades	History	Wallets	Trading	Delivery	Free	Paid from
AdjacentKalshi, Polymarket	Prices: yes	Order books: not stated	Trades: yes	History: yes	Wallets: not stated	Trading: not stated	RESTMCPFiles	Yes	$50 a month
Data Markets Prices Trades Price history Signals Delivery REST MCP bulk files (CSV, TSV) Markets covered Kalshi, Polymarket Sign-in none for public delayed API; API key or session Bearer token for realtime API Free use Yes. 15-minute delay; hourly history for previous 30 days or daily history for previous 90 days; 400 requests/10 seconds burst and 480/60 seconds sustained/IP. Rate limits Public 400 requests/10 seconds burst, 480/60 seconds sustained/IP. Pro 30/minute and 20,000/day; Premium 180/minute and 150,000/day/organization; 4 concurrent paid requests, up to 2 seconds queue wait. Cheapest paid plan $50 a month. Pro: realtime indices, rates, markets, history, research and MCP; 5 seats; 30 requests/minute and 20,000/day/organization. History from Not stated Links Documentation PricingChecked 6 November 2026
BravadoPolymarket, Predict.fun +1	Prices: yes	Order books: yes	Trades: yes	History: yeswith books	Wallets: yes	Trading: yes	RESTWebSocketMCPSQL	Yes	$49 a month
Data Markets Prices Order books Trades Price history Order-book history Wallets Resolutions Trading Delivery REST WebSocket MCP SQL Markets covered Polymarket, Predict.fun, Kalshi Sign-in API credentials with HMAC request signing; OAuth for MCP Free use Yes. 5,000 API credits/month; 5 requests/second; 1 key. Data API and MCP included; Market Data and Trade API require a paid plan or entitlement. Rate limits Free 5; Build 30; Accelerate 150; Scale 400 requests/second. Cheapest paid plan $49 a month. Build: 100,000 credits/month, 30 requests/second, 5 keys, WebSocket support; overage $8/10,000 credits. Annual billing advertises 20% off. History from Not stated Links Documentation PricingChecked 6 November 2026
DepthFeedPolymarket, Kalshi +1	Prices: yes	Order books: yes	Trades: yes	History: yessince 2026	Wallets: not stated	Trading: not stated	RESTWebSocketMCP	Yes	$29 a month
Data Markets Prices Order books Trades Price history Order-book history Resolutions Delivery REST WebSocket MCP Markets covered Polymarket, Kalshi, Limitless Sign-in API key Free use Yes. Explorer: rolling 7-day history; 1 request/second; 1 BTC live-book subscription. Pricing calls the free depth a recorded sample; docs describe full-venue access. Rate limits Explorer 1 request/second (docs: 60/minute); Quant 25/second and 1,000/minute; Research 50/second and 3,000/minute; Desk 100/second and 6,000/minute. Historical concurrency is separate. Cheapest paid plan $29 a month. Quant: 30-day history; 25 requests/second and 1,000/minute; 5 live subscriptions, 1 connection; 200 AI credits/month. History from 14 April 2026 Links Documentation PricingChecked 6 November 2026
KalshiSpyKalshi	Prices: yes	Order books: not stated	Trades: yes	History: not stated	Wallets: yes	Trading: not stated	RESTMCP	Yes	$116 a month
Data Markets Prices Trades Wallets Resolutions Signals Delivery REST MCP Markets covered Kalshi Sign-in none for public settled-win archive and market search; API key (Bearer or x-api-key) for live tools Free use Yes. Public settled-win archive: 60 requests/minute/IP. List cache 10 minutes; detail cache 1 hour. Live positions require a paid key. Rate limits Public archive 60 requests/minute/IP; Elite 500 requests/day; Lifetime 50/day; optional extra traffic roughly 60 requests/minute/account. Cheapest paid plan $116 a month. Elite LLM Access promotional price (regular $200): live API/MCP and 500 requests/day. $1,160/year promotional alternative; Lifetime $435 once includes 50/day. Optional overage $10/1,000 requests. History from Not stated Links Documentation PricingChecked 6 November 2026
MeshKalshi, Polymarket	Prices: not stated	Order books: not stated	Trades: not stated	History: not stated	Wallets: not stated	Trading: not stated	RESTMCP	Yes	$24.99 a month
Data Signals Delivery REST MCP SDKs: Python Markets covered Kalshi, Polymarket Sign-in API key (X-API-Key); hosted MCP browser login Free use Yes. 3 full-event transcript unlocks/day shared by web/API/MCP; 10 API/MCP searches/day; 15-segment preview. Pricing also shows 3/month, inconsistent with docs. Rate limits Free/Trial/Pro/Max API keys 60 requests/minute; Enterprise 300/minute; JWT web/hosted MCP 120/minute/user. Cheapest paid plan $24.99 a month. Pro: 15 transcript pulls/day, 150 searches/day, 450 pulls/month; 14-day free trial. Max $49.99/month. History from Not stated Links Documentation PricingChecked 6 November 2026
PolyRouterPolymarket, Kalshi +2	Prices: yes	Order books: not stated	Trades: yes	History: yes	Wallets: not stated	Trading: not stated	RESTMCP	Yes	–
Data Markets Prices Trades Price history Delivery REST MCP Markets covered Polymarket, Kalshi, Limitless, Manifold Sign-in API key (X-API-Key); homepage interactive tester is keyless Free use Yes. Free to get started; 100 requests/minute for all users. Rate limits 100 requests/minute for all users; higher limits by request. Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026
PredexonPolymarket, Kalshi +3	Prices: yes	Order books: yes	Trades: yes	History: yeswith books	Wallets: yes	Trading: not stated	RESTWebSocketMCPFiles	Yes	$49 a month
Data Markets Prices Order books Trades Price history Order-book history Wallets Resolutions Signals Delivery REST WebSocket MCP bulk files (Parquet) Markets covered Polymarket, Kalshi, Opinion, Limitless, Predict.fun Sign-in API key (x-api-key) Free use Yes. 1 request/second; 1,000 premium requests/month; free/historical endpoints unlimited by monthly quota, still rate-limited. No free WebSocket. Tick downloads billed separately; $50 credits conditional on adding payment method. Rate limits Free 1; Dev 20; Pro 100 requests/second; Enterprise custom. Cheapest paid plan $49 a month. Dev: 20 requests/second, 1M premium requests/month, Smart Money and Binance references, 10 WebSocket subscriptions × 10 items; overage $5/100,000 premium calls. History from Not stated Links Documentation PricingChecked 6 November 2026
PredictefyPolymarket, Polymarket US +14	Prices: yes	Order books: yes	Trades: yes	History: yes	Wallets: yes	Trading: yes	RESTWebSocketMCPSQL	Yes	$48.88 a month
Data Markets Prices Order books Trades Price history Wallets Resolutions Signals Trading Delivery REST WebSocket MCP SQL SDKs: TypeScript, Python Markets covered Polymarket, Polymarket US, Kalshi, Hyperliquid, Limitless, Opinion, Predict.fun, Myriad, Rain, Gemini, SX Bet, PRED, Pascal, XO, PredictStreet, Novig Sign-in API key; trading also uses client-side venue/wallet signing Free use Yes. 25,000 weighted credits/month; 60 requests/minute; 1 key; 2 live streams; 7-day history window; paper trading up to 10 open orders. Rate limits Free 60; Builder 300; Pro 3,000 requests/minute; Enterprise custom. Cheapest paid plan $48.88 a month. Builder: 250,000 credits/month, 300 requests/minute, 3 keys, 20 streams, 12-month history entitlement, bulk endpoints; no replay. $11/100,000 credit top-ups; annual advertises 20% off. History from Not stated Links Documentation PricingChecked 6 November 2026
PredictionMarketsPicksKalshi, Polymarket +3	Prices: yes	Order books: not stated	Trades: not stated	History: not stated	Wallets: not stated	Trading: not stated	MCPFiles	Yes	$14.99 a month
Data Markets Prices Signals Delivery MCP bulk files (JSON, CSV) Markets covered Kalshi, Polymarket, Polymarket US, Novig, ProphetX Sign-in none for free MCP tools; paid account/token for Pro tools Free use Yes. MCP page advertises 39 free tools; count varies by registry versus listed endpoint. No numeric request limit stated. Rate limits Not stated Cheapest paid plan $14.99 a month. Pro tools and edge feeds. Annual $150/year; code NFL26 first-year $111 promotion through December 31. Enterprise JSON/CSV outlet feeds contact sales. History from Not stated Links Documentation PricingChecked 6 November 2026
Polymarket Paper TraderPolymarket, Kalshi	Prices: yes	Order books: yes	Trades: not stated	History: not stated	Wallets: not stated	Trading: not stated	MCP	Yes	–
Data Markets Prices Order books Resolutions Delivery MCP Markets covered Polymarket, Kalshi Sign-in none for public upstream reads/local stdio MCP; self-hosted remote auth descriptions conflict (optional OAuth/OIDC versus unauthenticated transport) Free use Yes. Local open-source package and stdio MCP; no hosted quota stated, upstream venue limits apply. USD 10,000 virtual starting balance is simulation money, not a free financial benefit. Rate limits Not stated Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026
OpticOddsBetDEX, Betfair Exchange +17	Prices: yes	Order books: yes	Trades: not stated	History: yes	Wallets: not stated	Trading: not stated	RESTSSEMCP	?	Contact sales
Data Markets Prices Order books Price history Resolutions Signals Delivery REST SSE MCP Markets covered BetDEX, Betfair Exchange, Betfair Exchange (Australia), DraftKings Predictions, FD Predicts, Gemini Exchange, Kalshi, Limitless Exchange, Matchbook Exchange, Novig, Opinion Labs, Orbit Exchange, Polymarket, Polymarket (USA), Prophet X, Robinhood, SX Bet, Underdog Predictions, Sporttrade Sign-in API license key (X-Api-Key); Bearer key for MCP Free use Not stated Rate limits General v3 guidance: standard 2,500 requests/15 seconds; streaming 250/15 seconds; historical 10/15 seconds. Non-sport prediction-market endpoint entitlement enabled per key. Cheapest paid plan Contact sales History from Not stated Links Documentation PricingChecked 6 November 2026
pdataPolymarket, Kalshi +6	Prices: yes	Order books: not stated	Trades: not stated	History: yes	Wallets: not stated	Trading: not stated	RESTMCP	Yes	–
Data Markets Prices Price history Signals Delivery REST MCP Markets covered Polymarket, Kalshi, Manifold, Myriad, Limitless, Predict.fun, Opinion, Gemini Sign-in none Free use Yes. OpenAPI states all endpoints public, no auth and no rate cards. Numeric rate limit not stated. Rate limits Not stated Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026
racinglinesPolymarket, Kalshi +1	Prices: yes	Order books: yes	Trades: not stated	History: yeswith books	Wallets: not stated	Trading: not stated	MCP	?	–
Data Markets Prices Order books Price history Order-book history Signals Delivery MCP SDKs: Python Markets covered Polymarket, Kalshi, OG.com Sign-in Not stated Free use Not stated Rate limits Not stated Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026

Quick answers

Does Polymarket have a public API, and is it free?: Yes. Polymarket publishes its own API (REST, WebSocket, GraphQL). Reading public market data is free and needs no API key. Its rate limits and sign-in methods are in the table on this page.
Does Kalshi have a public API, and is it free?: Yes. Kalshi publishes its own API (REST, WebSocket, MCP). Reading public market data is free and needs no API key. Its rate limits and sign-in methods are in the table on this page.
Where can I get historical prediction market data?: 42 of the APIs here offer historical data, but only 5 state an exact start date; the earliest is Probalytics, from 2 October 2020. Use the "Historical data" filter to see them all.
Which prediction market data providers have a free tier?: 27 of the independent providers state a free tier or free use: 0xArchive, Adanos Software, Adjacent, Bravado, DepthFeed, KalshiSpy and 21 more. Limits differ; each row gives them.
How much does prediction market data cost?: The cheapest published plans range from $10 a month (outcometick) to $200 a month (Prediction Labs). What each plan includes differs, so compare the data and history columns too.
Which prediction market APIs work with AI agents?: 24 offer an MCP server that AI assistants can call directly: Kalshi, Limitless, Hunch, 0xArchive, Adjacent, Bravado and 18 more.

Nobody pays to be listed or for their position. A tick means the provider's own pages say it offers that data; a dash means they do not say. Using or reselling a market's data is governed by that market's own terms, whoever supplies it. Prices and limits change, so the provider's own page is the one that counts. Missing an API? Add it for free, or browse every data feed and API in the directory.

Every profile is built from the product's own pages, and Vultax keeps a dated copy of each one. How the directory is made. Companies already listed can manage their profile.