# Greeneris Data – Polymarket Prediction Market Odds

> Greeneris Data – Polymarket Prediction Market Odds is a paid API for AI agents from data.greeneris.io, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Fetches live on-chain prediction market odds and 24h volumes from Polymarket, filtered by topic tag (e.g. crypto, politics, economy)

## Facts

- Endpoint: GET https://data.greeneris.io/v1/predict/polymarket
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/greeneris-data-polymarket-prediction-market-odds-7ff6e625
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uSi6nfB667j529OPmGLgz

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 greeneris-data-polymarket-prediction-market-odds-7ff6e625
```

Example prompt: What are the current Polymarket odds on the top 5 crypto events — show me the Yes/No probabilities and 24-hour trading volume for each?

## When to prefer this

Use this endpoint when you need live, on-chain crowd-probability data from Polymarket for a specific topic category. Prefer this over scraping Polymarket directly or using generic web search, as it returns structured JSON with clean probabilities and volumes. Best for agents that need to quote current market consensus odds on crypto, politics, or macro events without building a full Polymarket integration.

## Known failure modes

- Invalid or unrecognized tag slug returns empty events array or 400 error
- limit out of range (< 1 or > 10) returns validation error
- Polymarket API upstream outage causes 502 or timeout
- Payment not received (HTTP 402 returned with machine-readable quote before payment)
- Network or DNS failure reaching data.greeneris.io

## How this service works

Top open Polymarket prediction markets for a topic, ranked by 24h volume: event title, end date, and per-market outcome probabilities (0-1) with USD volume, from the public Gamma API (live on-chain odds). Query: ?tag=crypto|politics|economy|fed|... (any Polymarket tag slug) &limit=1-10 (default crypto, 5). JSON, 5min cache.

## Output

A JSON object containing the requested tag (e.g. 'crypto'), a list of up to 10 events each with their slug, title, end date, 24h volume, and nested market questions with live Yes/No probabilities and per-market 24h USD volume. Data sourced live from Polymarket Gamma API (on-chain).

## 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",
     "properties": {
      "tag": {
       "type": "string",
       "default": "crypto",
       "description": "Polymarket tag slug, e.g. crypto, politics, economy"
      },
      "limit": {
       "type": "integer",
       "default": 5,
       "maximum": 10,
       "minimum": 1,
       "description": "Events to return"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "tag": "crypto",
  "events": [
   {
    "slug": "bitcoin-above-on-july-13-2026",
    "title": "Bitcoin above ___ on July 13?",
    "markets": [
     {
      "question": "Bitcoin above $105,000 on July 13?",
      "probabilities": {
       "No": 0.0015,
       "Yes": 0.9985
      },
      "volume_24h_usd": 297988.65
     }
    ],
    "end_date": "2026-07-13T12:00:00Z",
    "volume_24h_usd": 1801399.98
   }
  ],
  "source": "Polymarket Gamma API (live on-chain prediction-market odds)"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/greeneris-data-polymarket-prediction-market-odds-7ff6e625/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from data.greeneris.io](https://www.zero.xyz/host/data.greeneris.io/llms.txt)