GET /v1/odds/compare/{slug}

$0.02realtimetier: datacache 5sEngine A — Probability API

Venue-by-venue comparison for a market: implied probability, vig-adjusted probability (overround removed via the quoted book), summarized depth near the touch, plus the cross-venue spread and a disagreement flag when it exceeds 5 points.

Parameters

Example

curl "https://x402-factory.com/v1/odds/compare/republicans-hold-house-midterms-2026-11"

Example response

{
  "data": {
    "per_venue": [
      {
        "venue": "kalshi",
        "implied_p": 0.5965,
        "vig_adjusted_p": 0.5985,
        "depth_within_1c_usd": 23836.81,
        "depth_within_5c_usd": 80347.82
      },
      {
        "venue": "polymarket",
        "implied_p": 0.5702,
        "vig_adjusted_p": 0.5716,
        "depth_within_1c_usd": 30913.64,
        "depth_within_5c_usd": 123491.05
      }
    ],
    "venue_spread": 0.0263,
    "disagreement_flag": false
  },
  "meta": {
    "endpoint": "/v1/odds/compare/{slug}",
    "version": "1.0.0",
    "generated_at": "2026-08-18T22:54:16.966Z",
    "freshness": "realtime",
    "sources": [
      "kalshi",
      "polymarket"
    ],
    "request_id": "req_00000000",
    "docs": "https://x402-factory.com/docs/probability.odds-compare",
    "data_mode": "live"
  }
}

Response schema (data payload)

{
  "type": "object",
  "properties": {
    "per_venue": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "venue": {
            "type": "string",
            "enum": [
              "kalshi",
              "polymarket"
            ]
          },
          "implied_p": {
            "type": "number",
            "minimum": 0,
            "maximum": 1
          },
          "vig_adjusted_p": {
            "type": "number",
            "minimum": 0,
            "maximum": 1
          },
          "depth_within_1c_usd": {
            "type": "number"
          },
          "depth_within_5c_usd": {
            "type": "number"
          }
        },
        "required": [
          "venue",
          "implied_p",
          "vig_adjusted_p",
          "depth_within_1c_usd",
          "depth_within_5c_usd"
        ],
        "additionalProperties": false
      }
    },
    "venue_spread": {
      "type": "number",
      "minimum": 0,
      "maximum": 1
    },
    "disagreement_flag": {
      "type": "boolean"
    }
  },
  "required": [
    "per_venue",
    "venue_spread",
    "disagreement_flag"
  ],
  "additionalProperties": false
}

The platform wraps every payload in an envelope: { "data": …, "meta": { endpoint, version, generated_at, freshness, sources, request_id, docs, data_mode } }.

Payment (x402)

Unpaid requests receive 402 with payment requirements (accepts). Pay $0.02 in USDC on Base per call via an X-PAYMENT header — see docs.x402.org. With PAYMENT_MODE=disabled (local dev) the endpoint is open.

Errors