# Polymarket Outcome Token Tracker

> Polymarket Outcome Token Tracker is a paid API for AI agents from agents.x402stock.xyz, paid per call via MPP, $0.02/call, status unknown (last checked 2026-09-12).

Returns implied probability, today's VWAP and USD volume, indexed totals, and on-chain identity for a single Polymarket prediction market outcome token by its uint256 decimal token ID.

## Facts

- Endpoint: GET https://agents.x402stock.xyz/api/v1/prediction-markets/{id}
- Price: $0.02/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-09-12
- Activations on Zero: 0
- Provider: agents.x402stock.xyz
- Website: https://agents.x402stock.xyz
- Canonical page: https://www.zero.xyz/c/agents-x402stock-xyz-polymarket-outcome-token-tracker-8674ba75
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9hDAVmrERXAAzEqG8mSEo

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 agents-x402stock-xyz-polymarket-outcome-token-tracker-8674ba75
```

Example prompt: What's the current implied probability and today's USD trading volume for Polymarket outcome token 71321045679252212594626385532706912750332728571942532289631379312455583992654?

## When to prefer this

Use this endpoint when you have a specific Polymarket outcome token ID and need real-time implied probability, today's trading statistics (VWAP, volume, match count), cumulative indexed totals, and on-chain identity details (condition ID, question title, neg-risk) in a single call. Prefer this over general prediction market list endpoints when you already know the token ID and need deep data on one specific outcome. Best for monitoring, alerting, or enriching a known token with market microstructure data.

## Known failure modes

- Token ID not found or not yet indexed — returns error or empty identity block
- Invalid or malformed token ID string — likely 400/422 response
- Token ID exists but market data is stale if last_block is old
- Identity block may be null if the preparation transaction has not been resolved yet
- Payment failure via x402 if USDC balance is insufficient ($0.02 per call)

## How this service works

Use to track one Polymarket outcome token by its uint256 decimal token id: implied probability, today's VWAP and USD volume, indexed totals, plus on-chain identity (condition id, question title, neg-risk flag) resolved from the market's preparation transaction on Polygon. List active token ids via /prediction-markets. From x402stock, a market & economic data API (x402, USDC).

## Output

A JSON object containing: venue (polymarket), as_of timestamp, source (x402stock), market data (token_id, title, condition_id, neg_risk flag, implied_probability, last_side, vwap_today, volume_usd_today, matches_today, volume_usd_indexed, matches_indexed, last_block, updated_at), and an identity block (condition_id, question_id, oracle address, title, neg_risk) resolved from the Polygon preparation transaction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "id"
 ],
 "properties": {
  "id": {
   "type": "string",
   "description": "Prediction-market token or condition id."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "source",
  "as_of",
  "venue",
  "note",
  "market",
  "identity"
 ],
 "properties": {
  "note": {
   "type": "string"
  },
  "as_of": {
   "type": "string"
  },
  "venue": {
   "type": "string",
   "const": "polymarket"
  },
  "market": {
   "type": "object",
   "required": [
    "token_id",
    "title",
    "condition_id",
    "neg_risk",
    "implied_probability",
    "last_side",
    "vwap_today",
    "volume_usd_today",
    "matches_today",
    "volume_usd_indexed",
    "matches_indexed",
    "last_block",
    "updated_at"
   ],
   "properties": {
    "title": {
     "anyOf": [
      {
       "type": "string"
      },
      {
       "type": "null"
      }
     ]
    },
    "neg_risk": {
     "type": "boolean"
    },
    "token_id": {
     "type": "string"
    },
    "last_side": {
     "enum": [
      "buy",
      "sell"
     ],
     "type": "string"
    },
    "last_block": {
     "type": "number"
    },
    "updated_at": {
     "type": "string"
    },
    "vwap_today": {
     "anyOf": [
      {
       "type": "number"
      },
      {
       "type": "null"
      }
     ]
    },
    "condition_id": {
     "anyOf": [
      {
       "type": "string"
      },
      {
       "type": "null"
      }
     ]
    },
    "matches_today": {
     "type": "number"
    },
    "matches_indexed": {
     "type": "number"
    },
    "volume_usd_today": {
     "type": "number"
    },
    "volume_usd_indexed": {
     "type": "number"
    },
    "implied_probability": {
     "type": "number"
    }
   },
   "additionalProperties": false
  },
  "source": {
   "type": "string",
   "const": "x402stock"
  },
  "identity": {
   "anyOf": [
    {
     "type": "object",
     "required": [
      "condition_id",
      "question_id",
      "oracle",
      "title",
      "neg_risk"
     ],
     "properties": {
      "title": {
       "anyOf": [
        {
         "type": "string"
        },
        {
         "type": "null"
        }
       ]
      },
      "oracle": {
       "anyOf": [
        {
         "type": "string"
        },
        {
         "type": "null"
        }
       ]
      },
      "neg_risk": {
       "type": "boolean"
      },
      "question_id": {
       "anyOf": [
        {
         "type": "string"
        },
        {
         "type": "null"
        }
       ]
      },
      "condition_id": {
       "type": "string"
      }
     },
     "additionalProperties": false
    },
    {
     "type": "null"
    }
   ]
  }
 },
 "a
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agents-x402stock-xyz-polymarket-outcome-token-tracker-8674ba75/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agents.x402stock.xyz](https://www.zero.xyz/host/agents.x402stock.xyz/llms.txt)