# x402 Prediction Market Divergence

> x402 Prediction Market Divergence is a paid API for AI agents from x402tap.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Finds prediction-market questions where Polymarket and Kalshi show meaningfully different implied probabilities, surfacing cross-platform arbitrage signals.

## Facts

- Endpoint: GET https://x402tap.com/api/prediction-arb
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-prediction-market-divergence-27f37e76
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Jv7XRFCE4pyOkR9VXCz8k

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-prediction-market-divergence-27f37e76
```

Example prompt: Can you find prediction market questions where Polymarket and Kalshi disagree by at least 10 percentage points — filter for anything related to 'election' and show me the top 15 results?

## When to prefer this

Choose this endpoint when you need cross-platform prediction market divergence data that no single-platform API can provide — it uniquely combines Polymarket and Kalshi data to surface arbitrage signals. Prefer it over querying each platform separately when the goal is to find discrepancies rather than detail on a specific market.

## Known failure modes

- No markets meet the minDivergencePct threshold — returns empty results list
- Invalid query parameter type causes 400 error
- Limit outside 1-25 range rejected with validation error
- Upstream Polymarket or Kalshi data temporarily unavailable causing stale or partial results
- Payment not confirmed resulting in 402 response blocking the request

## How this service works

Find prediction-market questions priced differently on Polymarket vs. Kalshi — a cross-platform divergence signal built from data no single-platform competitor has

## Output

A list of matched prediction-market questions with their Polymarket and Kalshi implied probabilities, the calculated divergence in percentage points, and identifying metadata for each market — sorted by divergence or relevance.

## 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",
     "properties": {
      "q": {
       "type": "string",
       "description": "Optional keyword filter on the matched question text"
      },
      "limit": {
       "type": "string",
       "description": "Max matches to return, 1-25 (default 10)"
      },
      "minDivergencePct": {
       "type": "string",
       "description": "Minimum probability-point divergence to include, 0-100 (default 5)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-prediction-market-divergence-27f37e76/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402tap.com](https://www.zero.xyz/host/x402tap.com/llms.txt)