Same-event price comparison across Polymarket and Kalshi -- the arbitrage read. ...
https://www.x402financialdata.com/prediction-market-arb/:slugOverview
Same-event price comparison across Polymarket and Kalshi -- the arbitrage read. Given a Polymarket event slug, returns both venues' Yes probability for the same event, the spread in basis points, and a verdict. A missing Kalshi match comes back null, not an error. No key. $0.05/call.
Protocol
x402
Price
$0.05
Payment Asset
USD Coin
Payment Network
eip155:8453
Category
uncategorized
Provider
x402financialdata
Source
bazaar
Indexed
2026-11-09 23:08:25
Health
Status
unknown
Latency (p50)
—
Uptime (30d)
—
Reliability Score
—
Last Checked
Never
Last Healthy
Never
Consecutive Failures
0
x402 Payment Validation
Payment Requirements
—
Asset Verified
—
Facilitator
—
Input Schema
{
"method": "GET",
"pathParams": {
"slug": "xi-jinping-out-before-2027"
},
"type": "http"
}
Output Schema
{
"example": {
"kalshi": {
"ticker": "KXFEDHIKE-26",
"yes_probability": 0.58
},
"polymarket": {
"id": "fed-rate-hike-in-2026",
"yes_probability": 0.615
},
"slug": "fed-rate-hike-in-2026",
"source": "gamma-api.polymarket.com + external-api.kalshi.com",
"spread": 0.035,
"spread_bps": 350,
"title": "Fed rate hike in 2026?",
"verdict": "moderate spread"
},
"type": "json"
}