/prediction-markets/events

Description

Get the full details for one or more native, per-platform prediction-market events. Pass the platform:source_event_id IDs you got from /prediction-markets/events/ids, and this endpoint returns each event's title, description, category, canonical_event_id (populated once that event has been matched to an equivalent on another platform, empty otherwise), and its markets — each with a question, native source_market_id, and canonical_market_id.

Specific Parameter Information

For a full list of parameters, scroll to the bottom of this page.

You must pass at least one event_id. Authenticate with the X-Api-Key header.

event_id

(Required.) A native event ID in the form platform:source_event_id, obtained from /prediction-markets/events/ids. platform must be one of kalshi, polymarket.

Note: multiple IDs must be passed as repeated query parameters (e.g. event_id=X&event_id=Y), not comma-delimited values. IDs from different platforms can be mixed in the same request.

include_latencies

(Optional.) Set to true to add a latencies object ({"total": <seconds>}) showing how long the request took to process.

Example Responses

Single Event, Not Yet Matched

URL: https://api.opticodds.com/api/v3/prediction-markets/events?event_id=kalshi:EUEXIT

{
  "data": [
    {
      "platform": "kalshi",
      "source_event_id": "EUEXIT",
      "canonical_event_id": "",
      "title": "EU loses a member before 2030?",
      "description": "By 2030 If any country formally leaves the EU by Jan 1, 2030, then the market resolves to Yes.",
      "category": "politics",
      "markets": [
        {
          "canonical_market_id": "",
          "source_market_id": "EUEXIT-30",
          "question": "Will a country leave the EU by 2030?"
        }
      ]
    }
  ]
}

Single Event, Matched to a Canonical Event

URL: https://api.opticodds.com/api/v3/prediction-markets/events?event_id=kalshi:KXHOUSERACE-IL11-26

{
  "data": [
    {
      "platform": "kalshi",
      "source_event_id": "KXHOUSERACE-IL11-26",
      "canonical_event_id": "0084abc100ac5f34988afb271ce21392",
      "title": "IL-11 House winner?",
      "description": "",
      "category": "politics",
      "markets": [
        {
          "canonical_market_id": "98b1b58c0d7b50d5ac1484eb255baba6",
          "source_market_id": "KXHOUSERACE-IL11-26-D",
          "question": "Will Democratic win the House race for IL-11? — Bill Foster"
        },
        {
          "canonical_market_id": "d1f6e783bea95406b5bf6024d783da1f",
          "source_market_id": "KXHOUSERACE-IL11-26-R",
          "question": "Will Republican win the House race for IL-11? — Jeff Walter"
        }
      ]
    }
  ]
}

Multiple Events, Mixed Platforms

URL: https://api.opticodds.com/api/v3/prediction-markets/events?event_id=kalshi:KXHOUSERACE-IL11-26&event_id=polymarket:191455

{
  "data": [
    {
      "platform": "kalshi",
      "source_event_id": "KXHOUSERACE-IL11-26",
      "canonical_event_id": "0084abc100ac5f34988afb271ce21392",
      "title": "IL-11 House winner?",
      "description": "",
      "category": "politics",
      "markets": [
        {
          "canonical_market_id": "98b1b58c0d7b50d5ac1484eb255baba6",
          "source_market_id": "KXHOUSERACE-IL11-26-D",
          "question": "Will Democratic win the House race for IL-11? — Bill Foster"
        },
        {
          "canonical_market_id": "d1f6e783bea95406b5bf6024d783da1f",
          "source_market_id": "KXHOUSERACE-IL11-26-R",
          "question": "Will Republican win the House race for IL-11? — Jeff Walter"
        }
      ]
    },
    {
      "platform": "polymarket",
      "source_event_id": "191455",
      "canonical_event_id": "0084abc100ac5f34988afb271ce21392",
      "title": "IL-11 House Election Winner",
      "description": "This market will resolve according to the party of the candidate who wins the IL-11 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections.",
      "category": "politics",
      "markets": [
        {
          "canonical_market_id": "d1f6e783bea95406b5bf6024d783da1f",
          "source_market_id": "1283400",
          "question": "Will the Republican Party win the IL-11 House seat?"
        },
        {
          "canonical_market_id": "98b1b58c0d7b50d5ac1484eb255baba6",
          "source_market_id": "1283401",
          "question": "Will the Democratic Party win the IL-11 House seat?"
        }
      ]
    }
  ]
}