> ## Documentation Index
> Fetch the complete documentation index at: https://docs.predexon.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Cross-Platform Matching

> How Predexon matches equivalent markets across prediction market platforms

**Concepts learning path · 2 of 5.** Now that you understand a single market, see how Predexon links equivalent markets across venues. This unlocks cross-venue analysis and arbitrage.

## What Is Cross-Platform Matching?

Different prediction market platforms often list markets on the same real-world events. Predexon's matching system identifies **equivalent markets across Polymarket and Kalshi**, enabling you to compare prices, find arbitrage opportunities, and analyze cross-platform sentiment.

## How It Works

Predexon uses LLM-based technology to analyze market titles, descriptions, and resolution criteria across platforms. Each match receives a **similarity score** indicating how closely the markets align.

### Match Types

| Type              | Similarity Score | Description                                               |
| ----------------- | ---------------- | --------------------------------------------------------- |
| **Exact Match**   | ≥ 95             | Same underlying event with equivalent resolution criteria |
| **Related Match** | 80–94            | Similar or correlated events, but not identical           |

### Similarity Score Spectrum

* **98–100**: High confidence, virtually identical markets
* **96–97**: Confident, strong matches with minor wording variations
* **95–96**: Threshold, meets exact match criteria but may have edge cases in resolution

<Warning>
  Market matching uses LLM-based technology. A small percentage of matches may be incorrect. Always verify matches before making trading decisions.
</Warning>

## Endpoints

There are two matching endpoints:

### Find Matches

`GET /v2/matching-markets` - Given a market identifier from one platform, find its equivalent on the other platform. Returns both exact and related matches with similarity scores.

### Matched Pairs

`GET /v2/matching-markets/pairs` - Get all active exact-matched market groups (similarity ≥ 95), anchored on Polymarket with Kalshi, Limitless, Predict, and Opinion returned when available. Useful for scanning current cross-platform opportunities at once.

Both endpoints return expiration timestamps for each platform, allowing you to filter by when markets expire:

* `earliest_expiration_ts` - the soonest expiration across both platforms
* Platform-specific filters: `pm_expires_before`, `k_expires_before`, etc.

<Note>
  The `similarity` field may be `null` for matches created before January 4th, 2025.
</Note>

## Use Cases

* **Arbitrage detection** - compare prices on the same event across Polymarket and Kalshi to find mispricings
* **Cross-platform analysis** - see how different trader populations price the same event
* **Risk management** - monitor your exposure to the same event across multiple platforms

## Requirements

Cross-platform matching requires a **Dev plan or higher**. Free tier users will receive a `403` error. See [Rate Limits & Plans](/rate-limits) for details.

***

## Continue learning

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