Matching

Find matching markets across Polymarket and Kalshi platforms.

Provide either a Polymarket market slug OR a Kalshi market ticker (not both).

Important: You must provide exactly one of polymarket_market_slug or kalshi_market_ticker. Providing both parameters simultaneously is not allowed and will result in a 400 Bad Request error.

Returns

• Exact matches: Markets representing the same event
• Related matches: Markets for correlated events

Each category is further split by market status (active/closed).

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.

Note: The similarity field may be null for matches created before January 4th, 2025.

Finding Market Identifiers

Polymarket Market Slug

Refer to the Polymarket Gamma Markets API documentation for retrieving market slugs.

Note: A market slug is different from an event slug. An event can contain multiple markets, so ensure you're using the correct market-level identifier.

Kalshi Market Ticker

To find a market ticker:

1. Navigate to any market on Kalshi
2. Click the Timeline and Payout button on the market page to find the market ticker

Get all active exact-matched market pairs across Polymarket and Kalshi.

Returns pairs of markets that have been exactly matched, where both markets are currently active. Only returns exact matches (similarity >= 95) - related matches are excluded since one market can have multiple related matches which doesn't fit the pair concept.

This endpoint is useful for discovering arbitrage opportunities across platforms without needing to query individual markets.

Key Differences from Get Matching Markets

Notes

• Similarity scale: 0-100 (not 0-1). A similarity of 97 means 97% match confidence.
• Pagination: Results are ordered by similarity (highest first). Use pagination_key from the response to fetch the next page.
• Active pairs only: A pair is only returned if both the Polymarket and Kalshi markets are currently active/open.
• The similarity field may be null for matches created before January 4th, 2025.