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PolyRouter: what it does, what it costs, where it stops
Last checked 2026-09-08
PolyRouter is a unified REST API for prediction market data. One key at api-v2.polyrouter.io returns markets, events, series, order books, trades and OHLC price history across Polymarket, Kalshi, Manifold Markets, Limitless, ProphetX, Novig and SX.bet.
It is a data layer for developers, not a trading interface. The public REST surface has no order endpoints. It suits dashboards, research pipelines and sports odds comparison, and it is free during the open beta.
What it does
Endpoints cover platforms, markets (list, by ID, order book, trades, price history as OHLC candlesticks), events and series, sports (league info, games, awards, futures for NFL, NBA, NHL and MLB) and profiles (user profile and trade history from Kalshi or Polymarket).
Sports game IDs follow a fixed format, for example BUFvKC20251020@NFL, and a game endpoint returns market data from every platform that lists the game. Authentication is a single X-API-Key header.
- Order books are supported for Polymarket, Kalshi, Limitless and Manifold only.
- Events and series endpoints work for Polymarket and Kalshi only.
- Markets list limit was raised from 25 to 250 per request in v0.4.0 (December 9, 2025).
- v2.0.0 (January 6, 2026) moved the API to api-v2.polyrouter.io; older base URLs broke.
Pricing
Free. The docs state the service is in open beta and open to everyone, with every user limited to 100 requests per minute. There is no pricing page; polyrouter.io/pricing returns a 404. Higher limits are offered by contacting @fieldviolence on X.
Venues and data
Seven venues: Polymarket, Kalshi, Manifold Markets, Limitless, ProphetX, Novig and SX.bet. Manifold is play money, and ProphetX and Novig are sports exchanges, so the political and macro overlap is effectively Polymarket, Kalshi and Limitless.
A companion MCP server (github.com/fieldviolence/polyrouter-mcp, 31 stars, MIT) exposes the same data to Claude Code and other MCP clients. It can optionally place Kalshi and Polymarket orders, but only with your own venue credentials supplied in its .env file; PolyRouter itself never holds keys. The site footer says it is part of Context Markets.
Where it falls short
It reads and never writes. It shows the Kalshi and Polymarket prices side by side; executing on both means opening each venue separately, or a cross-venue terminal such as Kairos.
The flat 100 requests per minute cap is low for anyone polling order books across many markets. The changelog's latest entry is January 6, 2026, and the MCP repo was last pushed January 11, 2026, so treat feature velocity as slow. Historical trades and price history exist, but there is no stated retention window.
Who should use it
Developers who want a free, keyed, multi-venue market feed for a dashboard or a research notebook, and sports bettors comparing NFL or NBA lines across Kalshi, Polymarket, Novig and ProphetX.
Anyone who needs order placement, guaranteed uptime or a paid support tier should look at PMXT or the official venue SDKs.
Questions about PolyRouter
Is PolyRouter free?
Yes. The docs describe an open beta that is free and open to everyone, capped at 100 requests per minute per user. No paid tier is published.
Does PolyRouter support trading?
The REST API is data only. The separate open-source MCP server can place Kalshi and Polymarket orders if you supply your own venue credentials.
Which platforms does PolyRouter cover?
Polymarket, Kalshi, Manifold Markets, Limitless, ProphetX, Novig and SX.bet. Order books are available for the first four.
Does PolyRouter have historical data?
It has trades and OHLC price history endpoints. The docs do not state how far back the history goes.
Official APIs for building. One book for trading.
Rather trade the spread than build the plumbing? The free Kairos terminal gives you Kalshi, Polymarket and Predict.fun in one order book.