> ## 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.
# Find Matching Markets
> Find equivalent markets across Polymarket, Kalshi, Limitless, Predict, and Opinion
## Overview
Find matching markets across prediction market platforms. Given a Polymarket identifier (condition ID, market slug, or market ID), a Kalshi market ticker, a Limitless slug, a Predict identifier, or an Opinion identifier, discover equivalent or related markets on the other platforms.
Predict and Opinion can be queried by `market_id`, `condition_id`, or `token_id`. They can also be returned when a Polymarket, Kalshi, or Limitless query has verified canonical equivalents.
Provide **exactly one** identifier parameter, not multiple.
**LLM-Based Matching**: Market matching is powered by large language models (LLMs). There is a small percentage of markets where hallucinations may occur, resulting in invalid or incorrect matches. Always verify matches before making trading decisions.
## Match Types
Same underlying event with equivalent or near-equivalent resolution criteria. Similarity score >= 95.
Similar or correlated events (same entity different outcome, or same event different candidate). Similarity score between 80 and 95. Currently available for Polymarket, Kalshi, and Limitless anchors.
## Status Values
| Status | Description |
| -------- | -------------------------- |
| `active` | Market is open for trading |
| `closed` | Market is closed/resolved |
The `similarity` field may be `null` for matches created before January 4th, 2025.
## Predict and Opinion Matches
When canonical equivalents exist, the response can include `matches.PREDICT.exact` and `matches.OPINION.exact`. Predict and Opinion can also be used as the query anchor.
These blocks intentionally expose only execution identifiers and a title:
| Field | Description |
| -------------- | ----------------------------------------- |
| `market_id` | Venue-native market ID |
| `condition_id` | Venue-native condition ID, when available |
| `token_id` | Venue-native YES token ID, when available |
| `title` | Venue-native market title |
Predict and Opinion matches do not include `side`, `status`, `similarity`, or `explanation` in this endpoint. Legacy Polymarket, Kalshi, and Limitless matches retain their existing fields.
## OpenAPI
````yaml GET /v2/matching-markets
openapi: 3.1.0
info:
title: Predexon API
description: Prediction market data aggregation and matching API
version: 2.0.0
servers:
- url: https://api.predexon.com
security:
- apiKey: []
paths:
/v2/matching-markets:
get:
tags:
- matching
summary: Get Matching Markets
description: |-
Find matching markets across prediction market venues.
Provide exactly ONE of:
- polymarket_condition_id
- polymarket_market_slug
- polymarket_market_id
- kalshi_market_ticker
- limitless_slug
- predict_market_id / predict_condition_id / predict_token_id
- opinion_market_id / opinion_condition_id / opinion_token_id
Returns:
- Exact matches: Markets representing the same event
- Related matches: Markets for correlated events
- Predict/Opinion exact matches when canonical equivalents exist
operationId: get_matching_markets_v2_matching_markets_get
parameters:
- name: polymarket_condition_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Polymarket condition ID (hex hash)
title: Polymarket Condition Id
description: Polymarket condition ID (hex hash)
example: '0x6f14e52f6a1502a35406feea3f0e8d42502bbf1199e42c73a743fe1745ccc12c'
- name: polymarket_market_slug
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Polymarket market slug
title: Polymarket Market Slug
description: Polymarket market slug
example: will-chappell-roan-perform-at-the-2026-grammy-awards
- name: polymarket_market_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Polymarket market ID (numeric)
title: Polymarket Market Id
description: Polymarket market ID (numeric)
example: '1137275'
- name: kalshi_market_ticker
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Kalshi market ticker
title: Kalshi Market Ticker
description: Kalshi market ticker
example: KXPERFORMGRAMMYS-26-CHA
- name: limitless_slug
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Limitless market slug
title: Limitless Slug
description: Limitless market slug
- name: predict_market_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Predict market ID
title: Predict Market Id
description: Predict market ID
- name: predict_condition_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Predict condition ID
title: Predict Condition Id
description: Predict condition ID
- name: predict_token_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Predict YES token ID
title: Predict Token Id
description: Predict YES token ID
- name: opinion_market_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Opinion market ID
title: Opinion Market Id
description: Opinion market ID
- name: opinion_condition_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Opinion condition ID
title: Opinion Condition Id
description: Opinion condition ID
- name: opinion_token_id
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Opinion YES token ID
title: Opinion Token Id
description: Opinion YES token ID
- name: match_type
in: query
required: false
schema:
anyOf:
- $ref: '#/components/schemas/MatchType'
- type: 'null'
description: 'Filter by match type: ''exact'', ''related'', or ''all'' (default: all)'
title: Match Type
description: 'Filter by match type: ''exact'', ''related'', or ''all'' (default: all)'
example: exact
responses:
'200':
description: Successful Response
content:
application/json:
schema: {}
'400':
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
description: Bad Request
'404':
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
description: Not Found
'422':
description: Validation Error
content:
application/json:
schema:
$ref: '#/components/schemas/HTTPValidationError'
'500':
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
description: Internal Server Error
components:
schemas:
MatchType:
type: string
enum:
- exact
- related
- all
title: MatchType
description: Match type filter for cross-platform market matching.
ErrorResponse:
properties:
error:
type: string
title: Error
message:
type: string
title: Message
type: object
required:
- error
- message
title: ErrorResponse
description: Standard error response.
HTTPValidationError:
properties:
detail:
items:
$ref: '#/components/schemas/ValidationError'
type: array
title: Detail
type: object
title: HTTPValidationError
ValidationError:
properties:
loc:
items:
anyOf:
- type: string
- type: integer
type: array
title: Location
msg:
type: string
title: Message
type:
type: string
title: Error Type
type: object
required:
- loc
- msg
- type
title: ValidationError
securitySchemes:
apiKey:
type: apiKey
in: header
name: x-api-key
````