# Polymarket Resolution Risk & Flip Base Rate API

> Polymarket Resolution Risk & Flip Base Rate API is a paid API for AI agents from api.polym.uk, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Returns historical UMA dispute rates and outcome-flip base rates on Polymarket markets, broken down by category and criterion clarity type.

## Facts

- Endpoint: GET https://api.polym.uk/resolution-risk
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polymarket-resolution-risk-flip-base-rate-api-bdcc4c4a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_35K3B6yIgRbLAWUrODSYL

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-resolution-risk-flip-base-rate-api-bdcc4c4a
```

Example prompt: What are the historical UMA dispute rates and outcome flip rates across Polymarket market categories — and which categories currently have elevated resolution risk?

## When to prefer this

Use this endpoint when you need historical base-rate context for UMA resolution risk on Polymarket — specifically dispute frequency and outcome flip rates by category and criterion type. Prefer this over live market endpoints when you want statistical benchmarks rather than real-time signals, or when assessing whether a market category has structural resolution risk before entering a position.

## Known failure modes

- Insufficient sample size for certain categories returns flipInsufficientSample or disputeInsufficientSample flags set to true rather than numeric rates
- dataDegraded flag may be set true when underlying Polymarket data feeds are stale or incomplete
- No query parameters accepted — any attempt to filter by specific market or date range will be silently ignored
- Rate or category data may lag real-time market conditions since this reflects historical base rates, not live signals

## How this service works

UMA resolution dispute and flip base rates by category and criterion clarity; descriptive historical compatibility, not a market-specific forecast. BEFORE YOU PAY: free substitute https://dash.polym.uk/uma-base-rates.json and https://dash.polym.uk/uma-flip-rate.json. THIS ADDS: The two artifacts joined into one response, dispute axis and flip axis already aligned by category. The underlying numbers are the same ones in those two free files.

## Output

A JSON object containing: timestamp of data freshness, overall and per-category dispute rate percentages (high-volume and chronological), flip rate percentages, average lockup hours per market and if disputed, a list of elevated-risk categories, a breakdown by criterion clarity (checkable vs subjective dispute rates), caveats about data quality, and a human-readable 'howToRead' explanation. Some fields may be null if sample sizes are insufficient.

## 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": {},
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "asOf",
      "flipAsOf",
      "dataDegraded",
      "elevatedRiskCategories",
      "byCategory",
      "clarity",
      "flipOverall",
      "howToRead",
      "caveats"
     ],
     "properties": {
      "asOf": {
       "type": "string",
       "format": "date-time"
      },
      "caveats": {
       "type": "array",
       "items": {
        "type": "string"
       }
      },
      "clarity": {
       "type": [
        "object",
        "null"
       ],
       "required": [
        "checkableTitle",
        "uncheckableTitle"
       ],
       "properties": {
        "checkableTitle": {
         "type": "object",
         "required": [
          "marketsScanned",
          "disputeRatePct"
         ],
         "properties": {
          "disputeRatePct": {
           "type": "number",
           "maximum": 100,
           "minimum": 0
          },
          "marketsScanned": {
           "type": "integer",
           "minimum": 0
          },
          "disputedMarkets": {
           "type": "integer",
           "minimum": 0,
           "description": "Disputed markets in this title-clarity cell. Numerator of disputeRatePct."
          }
         },
         "additionalProperties": true
        },
        "uncheckableTitle": {
         "type": "object",
         "required": [
          "marketsScanned",
          "disputeRatePct"
         ],
         "properties": {
          "disputeRatePct": {
           "type": "number",
           "maximum": 100,
           "minimum": 0
          },
          "marketsScanned": {
           "type": "integer",
           "minimum": 0
          },
          "disputedMarkets": {
           "type": "integer",
           "minimum": 0,
           "description": "Disputed markets in this title-clarity cell. Numerat
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polymarket-resolution-risk-flip-base-rate-api-bdcc4c4a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.polym.uk](https://www.zero.xyz/host/api.polym.uk/llms.txt)