Free Prediction Market Data API — Real-Time Polymarket Odds, Signals & Sentiment from 28+ Sources

Ever wanted real-time prediction market data without scraping? I built Sirius API — a free REST API that gives you live Polymarket odds, algorithmic trading signals, sentiment analysis, and more. What you get (Free tier) Live markets — all active Polymarket markets with current odds Trading signals — 2,500+ signals/day from 6 detection layers (15-min delay on Free) Sentiment analysis — crypto Fear & Greed index, long/short ratios Sports odds — NBA, NFL, NHL, NCAA, soccer from ESPN + Kalshi Weather forecasts — NOAA data matched to prediction markets Cross-platform comparison — Polymarket vs Kalshi vs PredictIt odds Data Sources (28+) Polymarket, Kalshi, PredictIt, Manifold Markets, ESPN, The Odds API, NOAA, NHC, USGS, FRED, GDELT, FiveThirtyEight, Congress.gov, OpenFDA, Sleeper, Eurovision, Spotify Charts, TMDB, Google Trends, CourtListener, DOJ, Federal Register, Finnhub, and more. Quick start (Python) import requests headers = { " X-RapidAPI-Key " : " YOUR_KEY " , " X-RapidAPI-Host "