# Financial Data x402 – Prediction Markets Search

> Financial Data x402 – Prediction Markets Search is a paid API for AI agents from x402financialdata.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-15).

Search active prediction markets on Polymarket and Kalshi by keyword, returning probabilities, volumes, and close dates

## Facts

- Endpoint: GET https://x402financialdata.com/prediction-markets
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/financial-data-x402-prediction-markets-search-d10380a4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oAIQmQK7Os-UZ6D2dKhLe

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 financial-data-x402-prediction-markets-search-d10380a4
```

Example prompt: Search prediction markets for 'fed rate' and show me the top 5 results from Polymarket and Kalshi — I want to see the current probabilities and trading volumes.

## When to prefer this

Use this endpoint when an agent needs real-time crowd-sourced probability estimates on macro, political, or crypto events from decentralized prediction markets. Prefer it over traditional financial data APIs when you want market-implied probabilities (not prices) for future events, or when you need no API key and are willing to pay per call via USDC over x402.

## Known failure modes

- Keyword matches no markets: empty markets array returned for one or both sources
- Kalshi API limitation: markets outside the first ~1,600 open markets by internal ordering will not appear
- Source API outage: error field populated for the affected source, other sources may still return data
- Invalid or missing keyword parameter: request rejected with schema validation error
- Payment failure: x402 payment not accepted, call not executed

## How this service works

Pay-per-call stock, macro, on-chain, and crypto data over the x402 protocol. USDC on Base or Solana, no API keys, no subscriptions.

## Output

A JSON object keyed by source (e.g. 'polymarket', 'kalshi'), each containing a list of active markets matching the keyword. Each market includes an id, title, status, a list of outcomes with names and probabilities (0–1), a close date, total volume in USD, and 24-hour volume. Kalshi results carry a note that coverage is best-effort due to API limitations (~1,600 markets scanned).

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "keyword"
     ],
     "properties": {
      "limit": {
       "type": "integer",
       "description": "Max markets per source, default 10."
      },
      "keyword": {
       "type": "string",
       "description": "Search term, e.g. 'fed rate', 'recession', 'election'"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "kalshi": {
   "error": null,
   "markets": [],
   "search_coverage": "best-effort: Kalshi has no keyword-search API, so this scans only the first ~1,600 open markets by internal ordering; a match outside that window will not appear here"
  },
  "keyword": "fed rate",
  "polymarket": {
   "error": null,
   "markets": [
    {
     "id": "fed-rate-hike-in-2026",
     "title": "Fed rate hike in 2026?",
     "source": "polymarket",
     "status": "active",
     "outcomes": [
      {
       "name": "Yes",
       "probability": 0.615
      },
      {
       "name": "No",
       "probability": 0.385
      }
     ],
     "close_date": "2026-12-09T00:00:00Z",
     "volume_usd": 5645666.92,
     "volume_24h_usd": 624904.36
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/financial-data-x402-prediction-markets-search-d10380a4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402financialdata.com](https://www.zero.xyz/host/x402financialdata.com/llms.txt)