1. Get a test API key
Test keys are free and valid for 10 minutes. No signup required.api_key value — you’ll use it in the next step.
2. Make your first request
Use your API key in theX-API-Key header to fetch a Kalshi market:
3. Explore the API
Use the API Reference tab to browse all available endpoints. Every endpoint has a built-in playground where you can test requests directly in your browser.KLSI (Kalshi)
Market details, orderbooks, trade history, OHLCV candles, and analytics.
Polymarket
Market details, orderbooks, trade history, and price data.
Events & Search
Browse events by category and search across all markets.
WebSockets
Real-time streaming for orderbook and ticker updates.
Next steps
Authentication
Learn about production API keys, rate limits, and error handling.

