# x402-factory Cross-Venue Prediction Market Disagreement

> x402-factory Cross-Venue Prediction Market Disagreement is a paid API for AI agents from x402-factory.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-20).

Returns active prediction markets priced on both Kalshi and Polymarket, ranked by the gap in implied probability between the two venues, with direction, liquidity, and historical calibration data.

## Facts

- Endpoint: GET https://x402-factory.com/v1/cross-venue/disagreement?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-factory-cross-venue-prediction-market-disagreement-bddbcecf
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oUaQHvytnHjwg1gfeR66M

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability x402-factory-cross-venue-prediction-market-disagreement-bddbcecf
```

Example prompt: Show me which prediction markets have the biggest disagreement between Kalshi and Polymarket right now — filter to politics markets only and only show me gaps larger than 10 percentage points.

## When to prefer this

Use this endpoint when you need to identify specific markets where Kalshi and Polymarket have materially different implied probabilities, especially when you want venue-level liquidity context and historical calibration comparisons. Prefer it over scraping individual venues directly, or over general market data APIs that don't cross-reference multiple prediction market venues or compute disagreement gaps.

## Known failure modes

- No markets found for the given category filter — returns empty data array
- min_gap value outside 0–1 range returns a validation error
- Category string too short or too long returns a validation error
- Upstream venue data unavailable may cause stale or missing implied probabilities
- Calibration data may be null if insufficient resolved history exists for a category-venue pair

## How this service works

Where Kalshi and Polymarket disagree on the same event, ranked by gap — Active prediction markets priced on both Kalshi and Polymarket, ranked by how far the two venues disagree on the implied probability — with direction, each venue's liquidity, and, where each venue's own resolved history proves it, which has been better calibrated in that category. Derived analytics; the calibration claim is…

## Output

A ranked JSON array of active markets that appear on both Kalshi and Polymarket, each including: the market question, category, resolution date, each venue's implied probability and USD liquidity, the absolute probability gap, which venue prices the event higher, and (where available) historical calibration error per venue for that category along with the sample size and time window used to compute it.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "min_gap": {
       "type": "number",
       "maximum": 1,
       "minimum": 0,
       "description": "Only rows whose venue gap is at least this"
      },
      "category": {
       "type": "string",
       "maxLength": 20,
       "minLength": 2,
       "description": "Filter to one category, e.g. politics"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "data",
      "meta"
     ],
     "properties": {
      "data": {
       "type": "object",
       "required": [
        "markets",
        "linked_market_count",
        "calibration_reference"
       ],
       "properties": {
        "markets": {
         "type": "array",
         "items": {
          "type": "object",
          "required": [
           "slug",
           "question",
           "category",
           "resolution_date",
           "venues",
           "gap",
           "direction",
           "better_calibrated_venue",
           "calibration_basis",
           "calibration_computed_at"
          ],
          "properties": {
           "gap": {
            "type": "number",
            "description": "Max − min implied probability across the venues pricing this event"
           },
           "slug": {
            "type": "string"
           },
           "venues": {
            "type": "array",
            "items": {
             "type": "object",
             "required": [
              "venue",
              "implied_p",
              "liquidity_usd"
             ],
             "properties": {
              "venue": {
               "type": "string"
              },
              "implied_p": {
               "type": "number"
              },
              "liquidity_usd": {
               "type": "number"
              }
             },
             "additionalProperties": false
            }
           },
           "
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-factory-cross-venue-prediction-market-disagreement-bddbcecf/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-factory.com](https://www.zero.xyz/host/x402-factory.com/llms.txt)