Guides
Prediction-market data guides
Practical, honest guides to getting and using prediction-market data — the Polymarket and Kalshi APIs, real-time delivery, whale tracking, and the resolution that makes it trustworthy.
Polymarket API: how to get real-time Polymarket data
Polymarket's own Gamma, CLOB, and Data APIs explained — and how to get normalised signals plus calibrated resolution without building the pipeline yourself.
Kalshi API: how to get real-time Kalshi data
Kalshi's REST and WebSocket APIs, what's hard about them, and getting Kalshi data alongside Polymarket in one schema.
Polymarket vs Kalshi: what's the difference?
How the two biggest prediction markets differ — regulation, settlement, infrastructure — for traders and for builders pulling their data.
How to track Polymarket whales
Why large-trade and smart-wallet data on Polymarket is public, what's hard about using it, and how to get whale-flow signals by API.
How to tell if a Polymarket whale is actually good
Big isn't the same as good. The metrics that measure a wallet's real skill — win rate, Brier calibration, profit factor — plus smart-money flow, and how to get them by API.
Will this market resolve the way you think?
How Polymarket's UMA oracle and Kalshi's rules-based settlement work, where settlement risk hides, and how to get on-chain-anchored, calibrated resolution truth by API.
Real-time data: webhooks vs REST vs WebSocket
The three ways to move prediction-market data, when to reach for each, and how to skip building the ingestion layer.
Try it free — grab a dev key. A free developer key (no credit card) lets you try the REST API — see the docs. For real-time push and a commercial licence, request a key.