Quick Start
Make your first API call in minutes — no signup required for market data.
Authentication
Get an API key and send the credential triple the right way.
API Reference
Browse every endpoint across all of Kairos’s APIs, with request examples.
WebSocket Streams
Consume orderbooks, trades, and prices in real time.
What You Can Build
Trading Bots
Place, manage, and cancel orders over one persistent WebSocket — the lowest-latency path.
Market Analytics
Pull candles, trades, and metadata for thousands of prediction markets.
Cross-Venue Routing
Fill large sizes by routing orders across both legs of linked markets automatically.
Private Auctions
Execute institutional block trades privately through the Agora auction house.
Combo Markets
Buy and manage Polymarket parlay positions with a single API call.
Trader Analytics
Query PnL history, open positions, and trade fills by wallet address.
APIs at a Glance
Kairos exposes several API services, each optimized for a specific use case:The Market Data API is completely free and requires no signup or API key. Start fetching live data immediately.
Get Started in 4 Steps
1
Try market data for free
The Market Data API (
md.kairos.trade) requires no authentication. Fetch live market data right now with a single GET /v1/markets request — see the Quickstart.2
Get your API key
Create an account at app.kairos.trade and generate a key under Settings → API Keys. You receive a credential triple (
X-Client-Id, X-Api-Key, X-Api-Secret) — see Authentication.3
Connect your venue accounts
Use the Execution API’s onboarding endpoints to link your Polymarket, Kalshi, or Predict.fun account and enable trading.
4
Trade over WebSocket
Submit and cancel orders on the persistent
/ws socket rather than polling REST — it’s faster and simpler to build. See Order Execution over WebSocket.