# Polymarket Crypto Up/Down Markets via x402

> Polymarket Crypto Up/Down Markets via x402 is a paid API for AI agents from kr-x402-mvp.kgy5612.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-11-02).

Fetches Polymarket prediction market events and odds for crypto price up/down questions, searchable by keyword, paid per-call with USDC on Base via x402.

## Facts

- Endpoint: GET https://kr-x402-mvp.kgy5612.workers.dev/api/v1/pm/polymarket/crypto-updown?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-crypto-up-down-markets-via-x402-96d57858
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Q3eI9ge-s57shpSIyLMQB

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 polymarket-crypto-up-down-markets-via-x402-96d57858
```

Example prompt: Search Polymarket for Bitcoin up/down prediction markets and show me the top 5 events with their yes/no probabilities, best bid/ask, and which markets are most contested right now.

## When to prefer this

Choose this endpoint when you need real-time Polymarket prediction market odds for crypto price direction questions — especially for AI trading agents or onchain agents that need crowd-sourced probability signals without setting up API keys. It is ideal for quickly gauging market sentiment on specific crypto assets or macro events affecting crypto, and is cost-effective at $0.003 per call via x402 micropayment.

## Known failure modes

- Payment failure if USDC balance on Base is insufficient (x402 payment required)
- No events found if the search keyword matches no active Polymarket markets
- Stale data if Polymarket API is delayed or updated_at timestamp is old
- Rate limiting or worker timeout on the Cloudflare Workers backend
- Invalid query parameter types (e.g. non-integer limit) may return a 400 error

## How this service works

Pay-per-call crypto microdata for trading/onchain AI agents via x402 (USDC on Base): Base gas, token risk, balances, multi-venue prices, Hyperliquid book/funding, kimchi premium. No API keys.

## Output

Returns a list of Polymarket prediction market events matching the search keyword, each with event title, URL, end date, total liquidity, 24h volume, and an array of individual markets showing yes/no probabilities, best bid/ask prices, 24h volume, liquidity, 1-day probability change, and whether the market is contested. Also includes a top_contested summary highlighting the most actively debated market.

## 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",
       "examples": [
        "bitcoin",
        "ethereum",
        "fed rate",
        "election"
       ],
       "maxLength": 80,
       "description": "Search keyword (default crypto)"
      },
      "limit": {
       "type": "integer",
       "maximum": 20,
       "minimum": 1,
       "description": "Events to return (default 8)"
      },
      "markets": {
       "type": "integer",
       "maximum": 20,
       "minimum": 1,
       "description": "Markets per event (default 6)"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "q": "bitcoin",
  "events": [
   {
    "url": "https://polymarket.com/event/bitcoin-above-on-october-30",
    "title": "Bitcoin above ___ on October 30?",
    "markets": [
     {
      "no_prob": 0.38,
      "best_ask": 0.63,
      "best_bid": 0.61,
      "question": "Will the price of Bitcoin be above $80,000 on October 30?",
      "yes_prob": 0.62,
      "change_1d": 0.05,
      "contested": true,
      "liquidity": 50000,
      "volume_24h": 41000,
      "outcome_label": "80,000"
     }
    ],
    "end_date": "2026-10-30T16:00:00Z",
    "liquidity": 610000,
    "volume_24h": 281751.88
   }
  ],
  "source": "polymarket",
  "n_events": 1,
  "updated_at": "2026-10-29T15:30:00Z",
  "top_contested": {
   "event": "Bitcoin above ___ on October 30?",
   "question": "Will the price of Bitcoin be above $80,000 on October 30?",
   "yes_prob": 0.62,
   "volume_24h": 41000
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-crypto-up-down-markets-via-x402-96d57858/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from kr-x402-mvp.kgy5612.workers.dev](https://www.zero.xyz/host/kr-x402-mvp.kgy5612.workers.dev/llms.txt)