API Reference

Prediction Markets API

Universal endpoints for live Polymarket and Kalshi market data – probabilities, volume, outcomes and resolution history.

Authentication

All prediction-market endpoints require a valid API key. Pass it as the X-API-Key header. Keys are managed at /api-docs.

curl -H "X-API-Key: YOUR_KEY" "https://krokodds.com.au/api/v1/prediction-markets/universal?status=open&limit=10"

Data sources & sync

Polymarket – Gamma API + CLOB order book. On-chain prediction market with the deepest political, economic and crypto markets.
Kalshi – US-regulated event exchange. Public API for event contracts across politics, economics and sports.
Synced every 30 minutesby the universalMarketSync Cloud Function into Supabase.

GET/api/v1/prediction-markets/universal

Returns every active Polymarket and Kalshi market across all categories – politics, economics, crypto, sports and more. Markets are ordered by volume descending. Default status is open.

Query parameters

Parameter	Type	Default	Description
source	string	–	Filter by source. One of: polymarket, kalshi.
category	string	–	Filter by platform category (e.g. politics, economics, crypto, sports).
status	string	open	Market status. One of: open, closed, settled, halted.
limit	integer	50	Results per page. Min 1, max 200.
offset	integer	0	Pagination offset.
search	string	–	Case-insensitive text search on the market question.

Example request

curl -H "X-API-Key: sk_live_abc123" \
  "https://krokodds.com.au/api/v1/prediction-markets/universal?source=polymarket&status=open&limit=2"

Example response

{
  "success": true,
  "data": [
    {
      "id": "polymarket_0x8a3d...",
      "public_id": "a7f3c2e1b4d9087654321fedcba98765",
      "source": "polymarket",
      "platform_category": "politics",
      "market_id": "0x8a3d...",
      "question": "Will the US have a government shutdown in 2026?",
      "description": "This market resolves to Yes if the US federal government...",
      "outcomes": ["Yes", "No"],
      "outcome_prices": [0.35, 0.65],
      "status": "open",
      "result": null,
      "volume": 2845200,
      "liquidity": 189300,
      "best_bid": 0.34,
      "best_ask": 0.36,
      "end_date": "2026-12-31T00:00:00Z",
      "created_at": "2026-03-15T10:00:00Z",
      "fetched_at": "2026-08-11T12:30:00Z",
      "resolved_at": null
    },
    {
      "id": "polymarket_0x7b2c...",
      "public_id": "e5d4f3a2b1c0987654321098765432ab",
      "source": "polymarket",
      "platform_category": "economics",
      "market_id": "0x7b2c...",
      "question": "Will the Fed cut rates in September 2026?",
      "outcomes": ["Yes", "No"],
      "outcome_prices": [0.72, 0.28],
      "status": "open",
      "volume": 1520800,
      "best_bid": 0.71,
      "best_ask": 0.73,
      "fetched_at": "2026-08-11T12:30:00Z"
    }
  ],
  "meta": {
    "count": 2,
    "tier": "standard",
    "filter": { "source": "polymarket", "category": null, "status": "open" },
    "pagination": { "limit": 2, "offset": 0 },
    "note": "Full-catalog Polymarket + Kalshi markets across every category.",
    "timestamp": "2026-08-11T12:30:15Z"
  }
}

GET/api/v1/prediction-markets/universal/resolutions

Append-only archive of resolved Polymarket and Kalshi markets. Returns markets that have settled, ordered by resolution date descending. Useful for backtesting, historical analysis and settlement auditing.

Query parameters

Parameter	Type	Default	Description
source	string	–	Filter by source. One of: polymarket, kalshi.
category	string	–	Filter by platform category.
days	integer	30	Lookback window in days. Min 1, max 365.
limit	integer	50	Results per page. Min 1, max 200.
offset	integer	0	Pagination offset.

Example request

curl -H "X-API-Key: sk_live_abc123" \
  "https://krokodds.com.au/api/v1/prediction-markets/universal/resolutions?days=7&limit=2"

Example response

{
  "success": true,
  "data": [
    {
      "id": "kalshi_ABC123",
      "public_id": "9f8e7d6c5b4a3210fedcba9876543210",
      "source": "kalshi",
      "market_id": "ABC123",
      "question": "Will CPI exceed 3.5% in July 2026?",
      "platform_category": "economics",
      "outcomes": ["Yes", "No"],
      "result": "No",
      "final_prices": [0.18, 0.82],
      "volume_at_resolution": 892100,
      "resolved_at": "2026-08-10T16:00:00Z",
      "captured_at": "2026-08-10T16:05:12Z"
    }
  ],
  "meta": {
    "count": 1,
    "tier": "standard",
    "filter": { "source": null, "category": null, "days": 7 },
    "pagination": { "limit": 2, "offset": 0 },
    "note": "Resolved Polymarket + Kalshi markets, append-only resolution archive.",
    "timestamp": "2026-08-11T12:30:15Z"
  }
}

Notes

Volume is in the source platform's native unit (USD for both Polymarket and Kalshi). It represents total cumulative trading volume for the market.
Outcome prices are normalised to a 0–1 range (e.g. 0.65 = 65% implied probability). The array indices correspond to the outcomes array.
Rate limits vary by tier. See /api-docs for tier details.
CORS – all origins allowed (Access-Control-Allow-Origin: *).
Cache – responses are cached for 5 minutes (300s). The X-Cache-Age header indicates the cache window.

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