# Predge Whale Data – Polymarket Market Outcome Attestation

> Predge Whale Data – Polymarket Market Outcome Attestation is a paid API for AI agents from x402-api-production-266e.up.railway.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Returns a cryptographically signed ed25519 attestation of the resolved outcome for a specific Polymarket market, including resolution status, yes/no result, and optional side-correctness check.

## Facts

- Endpoint: GET https://x402-api-production-266e.up.railway.app/v1/attest/:conditionId
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/predge-whale-data-polymarket-market-outcome-attestation-50361198
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__WVipOWM3-nyLcHY-oSXA

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 predge-whale-data-polymarket-market-outcome-attestation-50361198
```

Example prompt: Can you get me a cryptographically signed attestation for Polymarket condition 0x3a1f2b8c... and check whether the yes side was correct?

## When to prefer this

Use this endpoint when you need cryptographically verifiable, independently auditable proof of a Polymarket market's settled outcome — especially when you cannot trust a single data source and need to verify offline using ed25519 signature verification. Prefer this over general Polymarket data endpoints when the use case is outcome attestation, audit trails, dispute resolution, or side-correctness checking rather than live prices or whale activity.

## Known failure modes

- 404 Not Found (not charged) – condition ID is unknown to the Predge dataset
- Unresolved market returns resolved: false, resolution: null, correct: null when side is queried
- Invalid condition ID format may return 400 or 404
- Network/railway deployment downtime returns 5xx

## How this service works

Cryptographically SIGNED resolved-outcome ATTESTATION for one Polymarket market (path param: 0x… condition id). Returns the SETTLED truth straight off the market row: resolved (bool), resolution (yes|no|null), resolved_at, and outcome_verified: {resolution: true}. Optional query param: side (yes|no) — when given, adds queried_side and correct (true iff side matches the resolution, null while unresolved). Every response carries an "attestation" envelope: an ed25519 signature over a canonical JSON payload plus the issuer's public_key, so any consumer can verify the outcome offline without trusting this endpoint. This is on-chain resolved outcome truth, NOT a prediction or model estimate — the "was this signal actually right", independently-verifiable primitive no other x402 source sells. 404 (not charged) for a condition id unknown to the Predge dataset.

## Output

A JSON envelope containing: resolved (bool), resolution ('yes', 'no', or null), resolved_at timestamp, outcome_verified object with resolution: true, and an attestation sub-object holding an ed25519 signature over the canonical payload plus the issuer's public_key for offline verification. If the optional 'side' param was provided, also includes queried_side and correct (true/false/null).

## 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"
    },
    "pathParams": {
     "type": "object"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "side": {
       "enum": [
        "yes",
        "no"
       ],
       "type": "string",
       "description": "Optional side to check correctness for (yes|no)"
      }
     }
    }
   },
   "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/predge-whale-data-polymarket-market-outcome-attestation-50361198/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-api-production-266e.up.railway.app](https://www.zero.xyz/host/x402-api-production-266e.up.railway.app/llms.txt)