Matching Markets by URL

Find equivalent markets across different prediction market platforms (Polymarket, Kalshi, etc.) for trending events using our aggregated intelligence engine.

Case Study

See how Elastics built their AI trading terminal on this endpoint→

Matches aren't always 100% accurate. Verify all data before executing a trade.

GET/matching-markets/url

Query Parameters

polymarket_urlsstring

A Polymarket URL to find matches for. Provide exactly one identifier per request — either a Polymarket URL or a Kalshi URL, not both.

kalshi_urlsstring

A Kalshi URL to find matches for. Provide exactly one identifier per request — either a Polymarket URL or a Kalshi URL, not both.

api_keystring

Legacy method. Can be passed as a query parameter, but header-based authentication is highly recommended for security.

Response Schema

successboolean

Indicates if the request was successful.

countinteger

Number of events matching the provided inputs.

eventsobject[]

titlestring

The human-readable name of the event (e.g. "2026 NBA Champions").

confidencestring

Match confidence level: "high" or "medium". Events with "low" confidence are excluded.

groupsobject[]

titlestring

The specific market group title (e.g. "Los Angeles Lakers").

marketsobject[]

Array of matched markets: source, source_url, id.

Error Responses

All errors return the same envelope. The code field is stable and programmatically branchable; error and message are human-readable. errors[] is present only on validation failures with field-level detail. See the full error code reference →

successboolean

Always `false` on error responses.

errorstring

Short, human-readable title (e.g. 'Invalid API Key.').

messagestring

Human-readable explanation for the error. Safe to surface in UIs.

codestring

Stable, hierarchical machine-readable code (e.g. 'validation.invalid_enum'). Use for programmatic handling.

doc_urlstring

Link to this code's entry in the Error Reference.

errorsobject[]

Optional. Present only on validation failures with field-level detail.

fieldstring

Name of the offending parameter.

codestring

Field-level machine code.

messagestring

Human-readable explanation.

Authentication

API Key

To secure your requests, we strongly recommend passing your API key via the X-API-Key header. This prevents sensitive keys from being exposed in access logs or browser history.

Request HeaderX-API-Key: pmx_test_5e8f...

Rate Limits

API rate limits are enforced based on the tier associated with your API key. Limits are tracked on two dimensions: requests per second and requests per month. Each completed request counts toward the global monthly quota. Separate endpoint-group monthly limits (matched markets, arbitrage, EV) only advance when the response body has success: true.

Usage is returned on responses via headers such as:

Response Headers (global)X-RateLimit-Limit-Second: 10X-RateLimit-Remaining-Second: 9X-RateLimit-Limit-Month: 1000X-RateLimit-Remaining-Month: 842Example (endpoint-group, when applicable)X-RateLimit-Limit-Arb-Month: 500X-RateLimit-Remaining-Arb-Month: 412

If you exceed a rate limit, the API returns a 429 status with a Retry-After header indicating when you can resume.

Request

Live API Key

Demo Mode

Verified

Market URLs

1 per request

PolymarketActive

KalshiPreview

Response

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