# Prediction Market Odds (Polymarket + Kalshi Aggregator)

> Prediction Market Odds (Polymarket + Kalshi Aggregator) is a paid API for AI agents from www.x402financialdata.com, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Searches Polymarket and Kalshi simultaneously by keyword, returning live real-money-backed outcome probabilities, trading volume, and close dates for matching prediction markets.

## Facts

- Endpoint: GET https://www.x402financialdata.com/prediction-markets
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/prediction-market-odds-polymarket-kalshi-aggregator-1d2bc913
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_jyTKxVN72tndjN8uOZbIj

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 prediction-market-odds-polymarket-kalshi-aggregator-1d2bc913
```

Example prompt: Search both Polymarket and Kalshi for prediction markets on 'Fed rate cut' and show me the live outcome probabilities, volume, and closing dates for up to 10 markets from each.

## When to prefer this

Choose this endpoint when you need real-money crowd-sourced forecasts for macro, political, or economic events and want to compare odds across both Polymarket and Kalshi in a single API call. It is uniquely valuable for events like FOMC decisions, elections, and recession probabilities where crowd forecasts often outperform analyst surveys. Not suitable for looking up stock prices, crypto spot prices, or earnings data.

## Known failure modes

- No markets found for the given keyword — try a broader or different search term
- Upstream API unavailability from Polymarket or Kalshi may result in partial or empty results
- Keyword too vague may return irrelevant markets
- Rate limit or payment failure returns 402 error

## How this service works

Prediction market odds in one call: keyword search across Polymarket AND Kalshi simultaneously -- no other market-data API aggregates both -- returning each match's live, real-money-backed outcome probabilities, volume, and close date. Crowd-sourced forecasts for Fed decisions, elections, and macro events often beat polls and analyst surveys; pairs naturally with this API's own FOMC/economic calendar. Not ticker-specific. $0.025/call.

## Output

A list of matching prediction markets from Polymarket and Kalshi, each including the market title, real-money-backed outcome probabilities (e.g. Yes/No percentage), trading volume, and market close date — aggregated from both platforms in a single response.

## 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"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/prediction-market-odds-polymarket-kalshi-aggregator-1d2bc913/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.x402financialdata.com](https://www.zero.xyz/host/www.x402financialdata.com/llms.txt)