Description

Get every native, per-platform event ID that OpticOdds tracks for a given prediction-market category. Each ID is returned in the form platform:source_event_id (e.g. kalshi:EUEXIT, polymarket:101101).

Use the IDs returned here as input to /prediction-markets/events (pass one as event_id) to pull full details — title, description, category, and per-market question / source_market_id.

Specific Parameter Information

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

You must pass category. Authenticate with the X-Api-Key header.

category

(Required.) One of the values returned by /prediction-markets/categories: politics, economics, finance, crypto, tech, culture, climate, health, geopolitics, companies, other.

Note: this parameter takes a single value. It is not repeatable — if it's passed more than once, only the last value is used.

platform

(Optional.) Restrict results to one platform. Valid values: kalshi, polymarket. Omit to return IDs from both platforms.

include_latencies

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

Example Responses

All Event IDs in a Category

URL: https://api.opticodds.com/api/v3/prediction-markets/events/ids?category=politics

{
  "data": [
    "kalshi:AMAZONFTC-29DEC31",
    "kalshi:CONTROLH-2026",
    "kalshi:EUEXIT",
    "kalshi:GOVPARTYCA-26",
    "polymarket:101101",
    "polymarket:101106",
    "polymarket:960993"
  ]
}

Filtered to a Single Platform

URL: https://api.opticodds.com/api/v3/prediction-markets/events/ids?category=crypto&platform=kalshi

{
  "data": [
    "kalshi:KXBTC-26SEP0411",
    "kalshi:KXBTC-26SEP0417",
    "kalshi:KXBTCY-27JAN0100",
    "kalshi:KXDOGE-26SEP0411",
    "kalshi:KXBTCMAXY-26DEC31"
  ]
}

With Latencies

URL: https://api.opticodds.com/api/v3/prediction-markets/events/ids?category=crypto&include_latencies=true

{
  "latencies": {
    "total": 0.0375
  },
  "data": [
    "kalshi:KXBNB-26SEP0411",
    "kalshi:KXBTC-26SEP0411",
    "polymarket:99445"
  ]
}

Resolving an ID (via /prediction-markets/events)

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

{
  "data": [
    {
      "platform": "kalshi",
      "source_event_id": "EUEXIT",
      "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": [
        {
          "source_market_id": "EUEXIT-30",
          "question": "Will a country leave the EU by 2030?"
        }
      ]
    }
  ]
}