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

13 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
Polymarket	Prices: yes	Order books: yes	Trades: yes	History: yes	Wallets: yes	Trading: yes	RESTWebSocketGraphQL	Yes	–
RTDS price feeds shut down on 30 November 2026; Polymarket's guide moves them to PolyBolt.
Data Markets Prices Order books Trades Price history Wallets Resolutions Trading Delivery REST WebSocket GraphQL SDKs: Python, TypeScript, Rust Markets covered Polymarket Sign-in none for public market data; API key with HMAC for private CLOB requests; wallet signature to derive keys and sign orders Free use Yes. Public market-data access without API key; IP/endpoint limits apply. No API subscription price stated; trading fees separate. Rate limits IP sliding windows: general 15,000 requests/10s; Gamma general 4,000/10s, markets 300/10s, events 500/10s; Data v2 general 800/10s, trades 300/10s, positions and prices-history 200/10s; CLOB general 9,000/10s, book/price 1,500/10s, prices-history 1,000/10s. POST /order burst 5,000/10s, sustained 120,000/10min. Separate per-signer trading token buckets also apply. Cheapest paid plan Not stated History from Not stated Links Documentation PricingChecked 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
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
LazyEdgeKalshi, Polymarket	Prices: yes	Order books: yes	Trades: not stated	History: not stated	Wallets: not stated	Trading: not stated	RESTWebSocket	No	$49.99 a month
Data Prices Order books Signals Delivery REST WebSocket Markets covered Kalshi, Polymarket Sign-in API key (Authorization: Bearer) Free use No. Free pick-em and lower paid terminal plans do not include API. Five or more Lazy Lions NFTs unlock API without subscription; asset acquisition is not described as free. Rate limits Not stated Cheapest paid plan $49.99 a month. Quant Node: API keys, agent guide, WebSocket and webhook edge alerts. Current subscriber price locks while active; later new subscriptions advertised at $149.99/month. History from Not stated Links Documentation PricingChecked 6 November 2026
NautilusTraderPolymarket	Prices: yes	Order books: yes	Trades: yes	History: yes	Wallets: yes	Trading: yes	RESTWebSocket	Yes	–
Data Markets Prices Order books Trades Price history Wallets Trading Delivery REST WebSocket SDKs: Python, Rust Markets covered Polymarket Sign-in none for public venue data; venue API credentials and wallet signature for trading Free use Yes. Open-source trading engine and adapter; underlying venue limits apply, no separate hosted data quota stated. Rate limits Not stated Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026
OddpoolKalshi, Polymarket	Prices: yes	Order books: yes	Trades: yes	History: yeswith books	Wallets: not stated	Trading: not stated	RESTWebSocketFiles	Yes	–
Oddpool is not taking new subscriptions; existing and free accounts continue.
Data Markets Prices Order books Trades Price history Order-book history Signals Delivery REST WebSocket bulk files (CSV) Markets covered Kalshi, Polymarket Sign-in API key Free use Yes. 1,000 requests/month; 1 request/second; 1 key; 1 WebSocket connection, 2 events, distribution channels only. Rate limits Free 1; Pro 10; Premium 25; Enterprise 500 requests/second; monthly quotas also apply. Cheapest paid plan Not stated History from Not stated Links Documentation PricingChecked 6 November 2026
PolyEdgePolymarket	Prices: not stated	Order books: not stated	Trades: yes	History: not stated	Wallets: yes	Trading: not stated	RESTSSE	Yes	$49 a month
Data Trades Wallets Signals Delivery REST SSE SDKs: TypeScript, Python, Rust, Go Markets covered Polymarket Sign-in API key (X-PolyEdge-Key) Free use Yes. 1 query/second; 30 analytics requests/day; 1 key; 1 trader stream tracking up to 3 addresses. Rate limits Free 1 query/second and 30/day; Starter 10/second and 1,000/day; Pro 20/second and 5,000/day; Builder 20/second and 50,000/day. Cheapest paid plan $49 a month. Starter personal licence: 10 queries/second, 1,000 analytics requests/day, 1 stream, up to 30 addresses or 1 tag and 2 series. Builder commercial licence $399/month. History from Not stated Links Documentation PricingChecked 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
Resolved MarketsPolymarket	Prices: yes	Order books: yes	Trades: yes	History: yeswith books	Wallets: not stated	Trading: not stated	RESTWebSocketMCP	Yes	$17 a month
Data Markets Prices Order books Trades Order-book history Resolutions Delivery REST WebSocket MCP Markets covered Polymarket Sign-in API key (X-API-Key); optional x402 per-request payment Free use Yes. 5,000 credits/month; 300 requests/minute; 2 keys; full book depth and unlimited retained history; MCP; no WebSocket. Rate limits Free and Pro 300; Scale 1,000; Enterprise 3,000 requests/minute. Cheapest paid plan $17 a month. Pro: 50,000 credits/month; 300 requests/minute; 5 keys; 1 WebSocket connection and backtest tools. x402 separately $0.001/request in USDC. History from Not stated Links Documentation PricingChecked 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
Climate SightKalshi, Polymarket	Prices: not stated	Order books: not stated	Trades: not stated	History: not stated	Wallets: not stated	Trading: not stated	RESTSSEWebSocket	?	–
Data Signals Delivery REST SSE WebSocket Markets covered Kalshi, Polymarket Sign-in API key (Bearer) Free use Not stated Rate limits 120 requests/minute/API key; unlimited SSE connections; WebSocket connection quota by account via support. SSE reconnect approximately every 400 seconds. Cheapest paid plan Not stated History from Not stated Links DocumentationChecked 6 November 2026
PolynodePolymarket	Prices: yes	Order books: yes	Trades: yes	History: yeswith books	Wallets: yes	Trading: yes	RESTWebSocket	Yes	$50 a month
Data Markets Prices Order books Trades Price history Order-book history Wallets Resolutions Trading Delivery REST WebSocket SDKs: TypeScript, Python, Rust Markets covered Polymarket Sign-in API key (x-api-key or WebSocket key); user-owned wallet authorization for trading Free use Yes. 1 event + 1 orderbook WebSocket connection; session 1 hour/day; 1 key; 10,000 filter items/subscription; snapshot_count 20; no V3 historical REST. Pricing displays 100K API requests and 5GB each of book/Chainlink and on-chain streams monthly; docs say monthly enforcement not active yet. Rate limits Account-shared V3 REST: Starter 1,000/minute standard and heavy; Growth 2,000/minute standard, 1,500 heavy; Enterprise 4,000 standard and 1,500 heavy by default. Free excludes V3 REST; 1-hour/day stream session. Cheapest paid plan $50 a month. Starter: V3 standard/heavy REST 1,000 requests/minute, 10+10 sockets, unlimited sessions; 3-day trial. Pricing includes 10M requests and 250GB each stream category, then $5/1M requests and $0.50/GB. History from Not stated Links Documentation PricingChecked 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.