# SiteCheck Polymarket Prediction Markets

> SiteCheck Polymarket Prediction Markets is a paid API for AI agents from api.sitecheck-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-23).

Searches Polymarket prediction markets by keyword or slug and returns current odds, implied probabilities, volume, and liquidity for matching markets.

## Facts

- Endpoint: GET https://api.sitecheck-api.workers.dev/api/prediction/polymarket?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-polymarket-prediction-markets-a8275b92
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_8VCIDT9KkCZ5JOe_vz28T

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 sitecheck-polymarket-prediction-markets-a8275b92
```

Example prompt: Search Polymarket for prediction markets about the Federal Reserve cutting interest rates and show me the current odds, implied probabilities, volume, and liquidity for the top 5 results.

## When to prefer this

Use this endpoint when you need real-time Polymarket prediction market data — specifically odds, implied probabilities, volume, and liquidity — by searching keywords or fetching a specific market by slug. Prefer this over generic web search when you need structured, machine-readable market data from Polymarket rather than scraped text. Ideal for agents that need to compare market-implied probabilities or track sentiment on specific events.

## Known failure modes

- No markets found for the given query or slug returns an empty markets array
- Invalid or non-existent slug returns no results
- Network timeout from upstream Polymarket gamma API
- Rate limit or upstream API unavailability causing 5xx errors
- Limit parameter out of range (must be 1–20) may return default or error

## How this service works

Active Polymarket prediction markets matching search words, or one market by slug: the question, each outcome with its price as an implied probability, volume, liquidity, end date and link. Closed markets are left out. Source: Polymarket Gamma API. Information only, not financial advice.

## Output

Returns a list of matching Polymarket markets, each with: the market question, a direct link, the slug, the end date, per-outcome prices and implied probability percentages, total USD trading volume, and USD liquidity. Also includes the data source URL and a timestamp for when the data was checked.

## 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": {
      "q": {
       "type": "string",
       "description": "Search words, e.g. bitcoin"
      },
      "slug": {
       "type": "string",
       "description": "Or one market's slug"
      },
      "limit": {
       "type": "string",
       "description": "1 to 20 (default 5)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "query": {
   "q": "bitcoin",
   "slug": null
  },
  "source": "https://gamma-api.polymarket.com (public-search)",
  "markets": [
   {
    "link": "https://polymarket.com/event/bitcoin-above-on-october-14-2026",
    "slug": "bitcoin-above-74k-on-october-14-2026",
    "endDate": "2026-10-14T16:00:00Z",
    "outcomes": [
     {
      "price": 0.9995,
      "outcome": "Yes",
      "impliedProbabilityPct": 100
     },
     {
      "price": 0.0005,
      "outcome": "No",
      "impliedProbabilityPct": 0.1
     }
    ],
    "question": "Will the price of Bitcoin be above $74,000 on October 14?",
    "volumeUsd": 27262,
    "liquidityUsd": 138901
   },
   {
    "link": "https://polymarket.com/event/bitcoin-above-on-october-14-2026",
    "slug": "bitcoin-above-76k-on-october-14-2026",
    "endDate": "2026-10-14T16:00:00Z",
    "outcomes": [
     {
      "price": 0.9995,
      "outcome": "Yes",
      "impliedProbabilityPct": 100
     },
     {
      "price": 0.0005,
      "outcome": "No",
      "impliedProbabilityPct": 0.1
     }
    ],
    "question": "Will the price of Bitcoin be above $76,000 on October 14?",
    "volumeUsd": 67080,
    "liquidityUsd": 40762
   }
  ],
  "checkedAt": "2026-10-14T07:00:23.176Z",
  "disclaimer": "Information only, not financial advice."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-polymarket-prediction-markets-a8275b92/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.sitecheck-api.workers.dev](https://www.zero.xyz/host/api.sitecheck-api.workers.dev/llms.txt)