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Quickstart

Create an API key, make one request, and inspect a real response.

Create a developer account at /signup.
Use X-API-Key in request headers.
Start with Polymarket markets or top spreads.
Real response from production APICross-platform spread example

Find live Kalshi/Polymarket price gaps

This request returns real data captured from production. Prices and spreads change over time.

Request
curl 'https://api.thepredictionmarkets.com/api/v2/spreads/top?limit=5&window=24' \
  -H 'X-API-Key: YOUR_TPM_API_KEY'
Response200 OK
{
  "data": [
    {
      "event_slug": "top-artist-on-spotify-us-in-2026",
      "event_title": "Top Artist on Spotify U.S. in 2026?",
      "outcome_title": "Drake",
      "platform_a": "polymarket",
      "platform_b": "kalshi",
      "price_a": 0.1055,
      "price_b": 0.79,
      "spread_bps": 6845,
      "confidence": 0.628,
      "is_stale": false,
      "updated_at": "2026-04-22T02:30:53.049830",
      "platform_a_url": "https://polymarket.com/event/top-spotify-artist-2026",
      "platform_b_url": "https://kalshi.com/markets/kxtopartistusa",
      "matching_strategy": "normalized_title_fallback",
      "match_quality": "auto_medium"
    },
    {
      "event_slug": "which-bills-will-become-law-in-2026-1",
      "event_title": "Which bills will become law in 2026?",
      "outcome_title": "Credit-card routing competition",
      "platform_a": "kalshi",
      "platform_b": "polymarket",
      "price_a": 0.08,
      "price_b": 0.44,
      "spread_bps": 3600,
      "confidence": 0.628,
      "is_stale": false,
      "updated_at": "2026-04-22T02:30:53.049830",
      "platform_a_url": "https://kalshi.com/markets/kxbills",
      "platform_b_url": "https://polymarket.com/event/which-bills-will-become-law-in-2026",
      "matching_strategy": "normalized_title_fallback",
      "match_quality": "auto_medium"
    }
  ],
  "count": 2
}

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Start with Kalshi and Polymarket market data, then add unified spreads, signals, alerts, and watchlists as your workflow grows.