What is Polymarket best for?

Developers wanting free public market and event data, including sports, from a prediction market exchange without credentials. Not ideal for: Sports-only data needs or bookmaker odds; it is a prediction exchange and sports endpoints and rate limits were not verified.

How much does Polymarket cost?

Polymarket does not publish prices on the pages we checked.

Does Polymarket have a free tier?

Yes. Polymarket lists a free plan called "Public read APIs".

What does Polymarket cover?

Polymarket is a betting exchange. Its sports: Multi-sport (40+); data: Trading & risk, Fixtures, Odds.

Does Polymarket have a WebSocket or streaming API?

No streaming is listed. Polymarket delivers data by REST, so you poll for updates.

What are the alternatives to Polymarket?

Close alternatives in the SportDex catalog: Matchbook Exchange, Smarkets, BETDAQ, SX Bet, Betfair Exchange API.

Betting exchange · United States

Polymarket

Prediction market exchange whose public Gamma API lists markets and events, including sports, without credentials; separate trading APIs and SDKs exist.

Facts verified against the provider's site on 2026-11-03

Commercial use: not disclosedBetting use: not disclosedMostly positive

Visit official site Open API docs Compare

Featured in:🆓 Best free sports APIs 💬 Most discussed sports APIs ❤️ Developer favourites 📈 Best betting odds APIs 🐙 Most used on GitHub ⚾ Best Baseball APIs 🎾 Best Tennis APIs 🏏 Best Cricket APIs ⛳ Best Golf APIs 🏇 Best Horse racing APIs 🏎️ Best Formula 1 APIs 🥊 Best MMA APIs 🏁 Best Motorsport APIs 🎓 Best College sports APIs

SportDex Score

#5 of 233 sports APIs

See the full ranking →

Popularity

Brand demand, developer discussions, GitHub repos and videos

Community & reliability

Tone of public discussions, liked vs criticised points, reliability complaints; based on 25+ public discussions.

Transparency

Public prices, docs, terms and coverage you can check before calling sales

Developer experience

Free access, docs, SDKs, OpenAPI, sandbox, realtime delivery, ecosystem

Computed from public data only; uptime and latency are not measured yet. Enterprise feeds that sell by contract score lower on transparency by design. How the score works

Starting price: Not public
Free access: Free tier
Sports: 1 (Multi-sport (40+))
Live data: Not disclosed
Delivery: Polling only (REST)
Discussions: 52 threads
GitHub adoption: 4.5k repos

Best for

Developers wanting free public market and event data, including sports, from a prediction market exchange without credentials.

Prediction market trackingSports event probability displays

Not ideal for

Sports-only data needs or bookmaker odds; it is a prediction exchange and sports endpoints and rate limits were not verified.

Limitations to check

− Not sports-only
− Sports endpoints and rate limits unverified
− Trading uses separate APIs

Written from the provider's own pages (source).

Last checked 2026-11-03

Polymarket at a glance

What is Polymarket best for?: Developers wanting free public market and event data, including sports, from a prediction market exchange without credentials. Not ideal for: Sports-only data needs or bookmaker odds; it is a prediction exchange and sports endpoints and rate limits were not verified.
How much does Polymarket cost?: Polymarket does not publish prices on the pages we checked.
Does Polymarket have a free tier?: Yes. Polymarket lists a free plan called "Public read APIs".
What does Polymarket cover?: Polymarket is a betting exchange. Its sports: Multi-sport (40+); data: Trading & risk, Fixtures, Odds.
Does Polymarket have a WebSocket or streaming API?: No streaming is listed. Polymarket delivers data by REST, so you poll for updates.
What do developers say about Polymarket?: Widely used as a free, no-key source of prediction-market prices (Gamma and CLOB APIs) for sports arbitrage bots, wallet trackers and odds aggregators, with many GitHub clients and MCP servers. Users note thin or missing historical data and the need to match events across Kalshi and sportsbooks; live-score speed is a concern.
What are the alternatives to Polymarket?: Close alternatives in the SportDex catalog: Matchbook Exchange, Smarkets, BETDAQ, SX Bet, Betfair Exchange API.

Commercial decision

Pricing & plan limits

Plan	Price	Requests	What's included
Public read APIs	Free	—	Gamma market data readable without keys; trading requires wallet authsource

Docs page fetched showed only a Gamma example and public SDK clients; sports endpoints, WebSocket and rate limits come from the batch note and are unverified. Not sports-only.

Before choosing a paid plan, confirm

• What counts as one request (per call, per market, per region?)

• What happens when you exceed the quota: blocked or billed

• Whether live and historical data are on your plan

• Whether your use (public app, betting, resale) is licensed

The critical question

Data coverage

Sports: Multi-sport (40+)
Data types: Trading & riskFixturesOdds
Key competitions: Not disclosed
Competitions: Not disclosed
Live / in-play: Not disclosed
Women's competitions: Not disclosed
Betting markets: Not disclosed
Bookmaker regions: Not disclosed
Bookmakers: Not disclosed
History depth: Not disclosed
Update frequency: Not disclosed
Name languages: Not disclosed
ID mapping: Not disclosed

Coverage often depends on the plan; confirm the exact league and season on your plan.

Before you build

Usage rights & access

Commercial use: Not disclosed
Betting products: Not disclosed
Redistribution: Not disclosed
Storing data: Not disclosed
Attribution: Not disclosed
Logos & photos: Not disclosed
Who can buy: Not disclosed
Verification (KYC): Not disclosed
Not available in: Not disclosed
Only available in: Not disclosed

Developer-ready evaluation

Integration & documentation

Protocols: REST
Formats: JSON
Authentication: none
SDKs: Not disclosed
OpenAPI spec: Not disclosed
Claimed latency: Not disclosed
Status page: Not disclosed
Sandbox / test keys: Not disclosed
Support: Not disclosed
SLA uptime: Not disclosed

Preview brief

# Integration brief: Polymarket

Goal: build a feature on Polymarket data. Use only the official documentation below as the source of truth.

## Known facts (from SportDex, verify before relying on them)
- Website: https://polymarket.com
- Docs: https://docs.polymarket.com/
- Sports: Multi-sport (40+)
- Data: Trading & risk, Fixtures, Odds
- Protocols: REST; formats: json
- Auth: none
- Free plan: Public read APIs
- Note: Docs page fetched showed only a Gamma example and public SDK clients; sports endpoints, WebSocket and rate limits come from the batch note and are unverified. Not sports-only.

## Verify before writing code
- live update frequency
- whether commercial use is allowed on the plan you pick
- exact endpoint paths, parameters and response fields (read the official docs, do not guess)

## Implementation rules
- Keep the API key on the server (environment variable, backend route or edge function); never ship it to the browser.
- Cache responses and respect rate limits; count how many requests each screen triggers.
- Handle errors explicitly: invalid key, quota exceeded (429), missing fields, empty fixtures, timeouts.
- Start with one demo request and log the raw response before building UI on assumed field names.

Data quality signals

Data source & company

Official partners: Not disclosed
How data is collected: Not disclosed
Certifications: Not disclosed
Payment methods: Not disclosed
Minimum contract: Not disclosed
Country: United States
Founded: Not disclosed

Reddit · Hacker News · Stack Overflow · GitHub · YouTube

What developers say

Mostly positivecoveragedata qualityalternativesdocs

Widely used as a free, no-key source of prediction-market prices (Gamma and CLOB APIs) for sports arbitrage bots, wallet trackers and odds aggregators, with many GitHub clients and MCP servers. Users note thin or missing historical data and the need to match events across Kalshi and sportsbooks; live-score speed is a concern.

Praised for

Public market data without credentials
Large ecosystem of SDKs and bots
Useful sharp-price signal versus sportsbooks
Many tutorials for Python access

Complaints

Historical data hard to find, especially before 2024
Manual cross-venue event matching
Not a live-score source

Our summary of public discussions, not a rating. Vendor posts are not counted as user opinion.

Discussions

Built a drop-in replacement for the-odds-api with prediction market data with free tier if anyone wants to try itr/algobetting · 2026-04
I run an odds API. Tell me the one market or book you can't get anywhere, and I'll try to ship it this weekr/algobetting · 2026-10
Prediction Market Arbitrage Bot for Kalshi + Polymarket: 160 alpha users, 9 releases, and what broker/SideProject · 2026-04
Does anyone else feel like in-game execution on sports prediction markets is missing conditional triggers?r/algobetting · 2026-10
Post-Mortem: Trading the World Cup on Polymarket (Custom API execution, Liquidity Farming, & Strategy Breakdown)r/algobetting · 2026-07
Real-time score fetchingr/algobetting · 2025-03
15% ROI bettor on the Clippers game to go under. Breakdown in caption:r/sportsbetting · 2026-03
I built the all-in-one platform for tracking sharp money. Here's how it works:r/sportsbetting · 2026-03
I built 2 APIs on my VPS and listed them on RapidAPIr/SideProject · 2026-03
Built a free arb/surebet scanner covering 20+ books: matching events, spotting skins and de-vigging. Looking to compare notesr/algobetting · 2026-11
Building an automated +EV betting bot for ProphetX: is this worth pursuing, or am I missing something?r/algobetting · 2026-10
Here's how I find sharp bets like this one before the game happens:r/sportsbetting · 2026-01

Open-source projects using it

caiovicentino/polymarket-mcp-server★ 736
lihanyu81/polymarket_lp_tool★ 617
Ashutosh0x/rust-finance★ 420
BlockRunAI/blockrun-mcp★ 391
chainstacklabs/polyclaw★ 359
livetennisapi/polymarket-tennis★ 261

Videos

Polymarket's Best Traders Keep Winning. So I Copied Them.Algovibes · 2026-10
How to Get Polymarket API Key (Step-by-Step Guide)Guidr · 2026-09
Polymarket SDK & API Explained in 7 MinutesCode & Nice · 2026-08
How To Get API Key From Polymarket! - TutorialHowToNow · 2026-08
Setting up and Interacting with the Polymarket CLOB APIwangr · 2026-02
Getting to know the Polymarket APIwangr · 2026-01

Shortlist next steps

Alternatives worth comparing

Matchbook ExchangeBetting exchange30
UK betting exchange offering a REST API for markets, offers and account data; read-only market data reportedly works without login, trading needs a funded account.
Multi-sport (40+)
Price not public0 discussions · 17 repos
SmarketsBetting exchange31
UK person-to-person betting exchange offering a streaming trading API for order entry and market data, with an official Python client.
⚡ StreamingMulti-sport (40+)Football (soccer)Horse racing
Price not public4 discussions · 38 repos
BETDAQBetting exchange29
UK betting exchange whose webservice API is open to verified account holders for a one-off fee, and which offers a streaming commercial API to operators.
Multi-sport (40+)
from £250 one-time8 discussions · 3 repos
SX BetBetting exchange51
Peer-to-peer crypto sports betting exchange with a public REST API for markets and orders and a realtime WebSocket feed for order books, scores and line updates.
Free tier⚡ StreamingMulti-sport (40+)
Free tier4 discussions · 77 repos
Betfair Exchange APIBetting exchange60
Betfair's developer API for its betting exchange: market prices, order books and bet placement. Free delayed key for development; live key needs an approved application and a one-off fee.
Free tier
from £299 one-time30 discussions · 272 repos

Polymarket vs Matchbook Exchange Polymarket vs Smarkets Polymarket vs BETDAQ Polymarket vs SX Bet Polymarket vs Betfair Exchange API

Evidence & transparency

Official sources

Facts were extracted from the provider's own pages on 2026-11-03. Empty fields mean the provider does not say, not that the feature is missing. How we know