Prediction Markets API
Real-time prediction market odds and probabilities from Polymarket and Kalshi. Browse active markets, get detailed odds on specific events, and discover trending bets -- all via x402 micropayments. Merges data from both platforms so agents get the most complete view of market sentiment.
What It Does / Endpoints
| Endpoint | Price | Description |
|---|
POST /api/markets | $0.005 | List active prediction markets with odds, volume, categories from both Polymarket and Kalshi |
POST /api/odds | $0.005 | Detailed odds for a specific market (by ID or search query) -- searches both platforms |
POST /api/trending | $0.003 | Top trending markets ranked by volume from both sources |
Example Request / Response
List Markets
curl -X POST https://prediction-markets-production.up.railway.app/api/markets \
-H "Content-Type: application/json" \
-d '{"category": "politics", "limit": 5, "sort": "volume"}'
{
"markets": [
{
"id": "0x1234...",
"question": "Will Trump win the 2028 presidential election?",
"outcomes": ["Yes", "No"],
"outcomePrices": { "Yes": 0.42, "No": 0.58 },
"volume": 15420000,
"volume24h": 234000,
"liquidity": 890000,
"endDate": "2028-11-06T00:00:00Z",
"category": "politics",
"active": true,
"source": "polymarket"
},
{
"id": "PRES-2028-DEM",
"question": "Will a Democrat win the 2028 presidential election?",
"outcomes": ["Yes", "No"],
"outcomePrices": { "Yes": 0.55, "No": 0.45 },
"volume": 8200000,
"volume24h": 0,
"liquidity": 0,
"endDate": "2028-11-06T00:00:00Z",
"category": "politics",
"active": true,
"source": "kalshi"
}
],
"count": 5,
"sort": "volume",
"category": "politics",
"source": "polymarket+kalshi"
}
Filter by platform:
curl -X POST https://prediction-markets-production.up.railway.app/api/markets \
-H "Content-Type: application/json" \
-d '{"source": "kalshi", "limit": 5}'
Get Odds (Search by Query)
curl -X POST https://prediction-markets-production.up.railway.app/api/odds \
-H "Content-Type: application/json" \
-d '{"query": "bitcoin 100k"}'
{
"id": "0xabcd...",
"question": "Will Bitcoin reach $100k by December 2026?",
"outcomes": ["Yes", "No"],
"outcomePrices": { "Yes": 0.65, "No": 0.35 },
"volume": 8900000,
"volume24h": 120000,
"liquidity": 450000,
"endDate": "2026-12-31T00:00:00Z",
"category": "crypto",
"active": true,
"source": "polymarket",
"matchedFrom": 3
}
Trending Markets
curl -X POST https://prediction-markets-production.up.railway.app/api/trending \
-H "Content-Type: application/json" \
-d '{"limit": 5}'
{
"trending": [
{
"id": "0x5678...",
"question": "Will the Fed cut rates in July 2026?",
"probability": 0.73,
"outcomePrices": { "Yes": 0.73, "No": 0.27 },
"volume24h": 890000,
"totalVolume": 12500000,
"category": "politics",
"endDate": "2026-07-31T00:00:00Z",
"active": true,
"source": "polymarket"
},
{
"id": "FED-RATE-JUL26",
"question": "Will the Fed cut rates in July 2026?",
"probability": 0.71,
"outcomePrices": { "Yes": 0.71, "No": 0.29 },
"volume24h": 0,
"totalVolume": 5400000,
"category": "politics",
"endDate": "2026-07-31T00:00:00Z",
"active": true,
"source": "kalshi"
}
],
"count": 5,
"source": "polymarket+kalshi"
}
Use Cases
- Election odds: Get real-time probabilities on political outcomes backed by real money from both crypto-native (Polymarket) and CFTC-regulated (Kalshi) platforms
- Crypto predictions: Check market consensus on price targets, ETF approvals, protocol upgrades
- Event forecasting: Find the crowd-sourced probability of any major world event
- Cross-platform comparison: Compare odds between Polymarket and Kalshi for the same events
- Research & analysis: Use prediction market data as a signal for decision-making
- News impact: See how breaking events shift market probabilities in real time
MCP Integration
Add to your Claude Desktop or Cursor MCP config:
{
"mcpServers": {
"prediction-markets": {
"url": "https://prediction-markets-production.up.railway.app/sse"
}
}
}
Tools available via MCP:
prediction_list_markets -- Browse active markets by category, sort, and platform (Polymarket or Kalshi)prediction_get_market_odds -- Get detailed odds by market ID or search query (searches both platforms)prediction_trending_markets -- Discover trending markets by volume from both sources
Payment
All endpoints are gated by x402 micropayments (USDC on Base L2). Agents pay automatically per call -- no API keys, no subscriptions.
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