Prediction market arbitrage and same-outcome spread API for Polymarket, Kalshi,
Prediction market arbitrage and same-outcome spread API for Polymarket, Kalshi, and Gemini. Finds YES or NO price gaps across venues.
Asked 100.0x its listed price for its own exampleour last check, 2026-09-24
1 of 1checks answered this week
263 msmedian answer time
$0.001listed price per call
$0.1price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://api.seerium.xyz/v1/prediction/arb/same-outcome-spread
| Category | Market data |
|---|---|
| Provider host | api.seerium.xyz |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.1 | 263 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"includeIndicative": true,
"limit": 3,
"minEdge": 0,
"sources": "polymarket,kalshi,gemini"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"properties": {
"includeIndicative": {
"description": "Optional flag for indicative price-only rows. Defaults to true.",
"type": "boolean"
},
"limit": {
"description": "Optional maximum arb rows to return. Defaults to 20 and is hard-capped at 20.",
"maximum": 20,
"minimum": 1,
"type": "number"
},
"minEdge": {
"description": "Optional minimum net arb edge as a decimal or percentage-style value.",
"minimum": 0,
"type": "number"
},
"outcome": {
"description": "Optional same-outcome filter.",
"enum": [
"yes",
"no"
],
"type": "string"
},
"sources": {
"description": "Optional comma-separated venue filter: polymarket, kalshi, gemini.",
"type": "string"
}
},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}