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GET
/
v1
/
matching-markets
# From Polymarket to Kalshi
curl -H "x-api-key: YOUR_API_KEY" \
  "https://api.predexon.com/v1/matching-markets?polymarket_market_slug=will-the-carolina-hurricanes-win-the-metropolitan-division-123"

# From Kalshi to Polymarket
curl -H "x-api-key: YOUR_API_KEY" \
  "https://api.predexon.com/v1/matching-markets?kalshi_market_ticker=KXNHLMETROPOLITAN-26-CAR"
{
  "query": {
    "platform": "KALSHI",
    "market_ticker": "KXNHLMETROPOLITAN-26-CAR",
    "title": "Will Carolina Hurricanes win the NHL Metropolitan Division?",
    "yes_subtitle": "Carolina Hurricanes",
    "status": "active"
  },
  "matches": {
    "POLYMARKET": {
      "exact": [
        {
          "market_slug": "will-the-carolina-hurricanes-win-the-metropolitan-division-123",
          "title": "Will the Carolina Hurricanes win the Metropolitan Division?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes), same outcome (win the 2025–26 NHL Metropolitan Division), same timeframe (2025–26 regular season) — will always resolve identically.",
          "similarity": 0.97
        }
      ],
      "related": [
        {
          "market_slug": "will-the-carolina-hurricanes-win-the-2026-nhl-stanley-cup",
          "title": "Will the Carolina Hurricanes win the 2026 NHL Stanley Cup?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes) but different outcome/event (win the 2026 Stanley Cup vs win the 2025–26 Metropolitan Division).",
          "similarity": 0.94
        },
        {
          "market_slug": "will-the-new-jersey-devils-win-the-metropolitan-division-424",
          "title": "Will the New Jersey Devils win the Metropolitan Division?",
          "status": "active",
          "explanation": "Same event (which team wins the 2025–26 Metropolitan Division) but different candidate/team (New Jersey Devils vs Carolina Hurricanes) — competitive and thus correlated.",
          "similarity": 0.92
        },
        {
          "market_slug": "will-the-carolina-hurricanes-make-the-nhl-playoffs",
          "title": "Will the Carolina Hurricanes make the NHL Playoffs?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes) but different outcome (make the 2025–26 NHL Playoffs vs win the 2025–26 Metropolitan Division).",
          "similarity": 0.91
        }
      ]
    }
  },
  "summary": {
    "total_matches": 4,
    "exact_matches": 1,
    "related_matches": 3,
    "platforms": ["POLYMARKET"]
  }
}

Overview

Find matching markets across prediction market platforms. Given a Polymarket market slug OR a Kalshi market ticker, discover equivalent or related markets on the other platform.
polymarket_market_slug
string
Polymarket market slug to find matches for
kalshi_market_ticker
string
Kalshi market ticker to find matches for
Provide exactly one of polymarket_market_slug or kalshi_market_ticker, not both.
query
object
Information about the queried market
matches
object
Matches grouped by platform
summary
object
# From Polymarket to Kalshi
curl -H "x-api-key: YOUR_API_KEY" \
  "https://api.predexon.com/v1/matching-markets?polymarket_market_slug=will-the-carolina-hurricanes-win-the-metropolitan-division-123"

# From Kalshi to Polymarket
curl -H "x-api-key: YOUR_API_KEY" \
  "https://api.predexon.com/v1/matching-markets?kalshi_market_ticker=KXNHLMETROPOLITAN-26-CAR"
{
  "query": {
    "platform": "KALSHI",
    "market_ticker": "KXNHLMETROPOLITAN-26-CAR",
    "title": "Will Carolina Hurricanes win the NHL Metropolitan Division?",
    "yes_subtitle": "Carolina Hurricanes",
    "status": "active"
  },
  "matches": {
    "POLYMARKET": {
      "exact": [
        {
          "market_slug": "will-the-carolina-hurricanes-win-the-metropolitan-division-123",
          "title": "Will the Carolina Hurricanes win the Metropolitan Division?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes), same outcome (win the 2025–26 NHL Metropolitan Division), same timeframe (2025–26 regular season) — will always resolve identically.",
          "similarity": 0.97
        }
      ],
      "related": [
        {
          "market_slug": "will-the-carolina-hurricanes-win-the-2026-nhl-stanley-cup",
          "title": "Will the Carolina Hurricanes win the 2026 NHL Stanley Cup?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes) but different outcome/event (win the 2026 Stanley Cup vs win the 2025–26 Metropolitan Division).",
          "similarity": 0.94
        },
        {
          "market_slug": "will-the-new-jersey-devils-win-the-metropolitan-division-424",
          "title": "Will the New Jersey Devils win the Metropolitan Division?",
          "status": "active",
          "explanation": "Same event (which team wins the 2025–26 Metropolitan Division) but different candidate/team (New Jersey Devils vs Carolina Hurricanes) — competitive and thus correlated.",
          "similarity": 0.92
        },
        {
          "market_slug": "will-the-carolina-hurricanes-make-the-nhl-playoffs",
          "title": "Will the Carolina Hurricanes make the NHL Playoffs?",
          "status": "active",
          "explanation": "Same entity (Carolina Hurricanes) but different outcome (make the 2025–26 NHL Playoffs vs win the 2025–26 Metropolitan Division).",
          "similarity": 0.91
        }
      ]
    }
  },
  "summary": {
    "total_matches": 4,
    "exact_matches": 1,
    "related_matches": 3,
    "platforms": ["POLYMARKET"]
  }
}

Match Types

Exact Matches

Same underlying event with equivalent resolution criteria. Ideal for arbitrage. Similarity score >= 0.95.

Related Matches

Similar or correlated events (same entity different outcome, or same event different candidate). Useful for hedging and research. Similarity score between 0.90 and 0.95.
The similarity field may be null for matches created before January 4th, 2025.

Authorizations

x-api-key
string
header
required

API key for authentication. Get your free key at dashboard.predexon.com

Query Parameters

polymarket_market_slug
string | null

Polymarket market slug to find matches for

kalshi_market_ticker
string | null

Kalshi market ticker to find matches for

Response

Successful Response

Response for Polymarket market matching query.

query
PolymarketQueryInfo · object
required

Polymarket query information.

matches
Matches · object
required
summary
MatchSummary · object
required

Summary of matches.