Polymarket Intelligence API · Market Authenticity

import { wrapFetchWithPayment } from "@x402/fetch";
import { privateKeyToAccount } from "viem/accounts";

const account = privateKeyToAccount(process.env.PRIVATE_KEY);
const fetchWithPay = wrapFetchWithPayment(fetch, account);

const res = await fetchWithPay("https://api.polym.uk/market-authenticity/:conditionId", {
  method: "GET",
});
const data = await res.json();

curl -X GET \
  "https://api.polym.uk/market-authenticity/:conditionId" \
  -H "X-PAYMENT: <signed x402 payment>"

{
  "apparentVolumeUsd": 250883.87,
  "asOf": "2026-09-01T03:42:26.765Z",
  "bucket": "broad",
  "caveats": [
    "SHOWCASE, NOT THE PAID RESPONSE: what you see is one market of the covered set, and the route answers for any covered conditionId you pass. Nothing is masked or invented: every value is a dated measurement, kept so you can read the shape, the units and the field semantics. The schema published beside it is complete; a paid call returns the complete set.",
    "EXAMPLE ONLY: what this route returns for one market of the free public snapshot of 2026-09-01T03:42Z, then frozen. A live response carries its own asOf and current values.",
    "Coverage is partial and declared. Only markets decomposed by window volume answer with found:true; a conditionId outside that set returns 422, is not billed, and carries a note instead of metrics. GET /coverage is free and reports how many markets are decomposed right now.",
    "Descriptive FACT for the observed window. Never an accusation of fraud, nor a wash or skill label.",
    "apparentVolumeUsd counts executed trades, which is not the same as liquidity or open interest. It is taker-side and window-scoped, not lifetime.",
    "Concentration is measured among the OBSERVED TAKERS (the tape is taker-only). effectiveTraders = 1/HHI, which exposes what distinctTraders hides.",
    "onchainCounterparties is how many distinct counterparties the dominant taker traded against: a FACT, not a wash verdict. The proxy wallet is not the owner, and the graph is one hop deep.",
    "betResolvedInFavor means the dominant direction coincided with the resolution. One sample; neither PnL nor evidence of skill.",
    "resolutionRisk is the category BASE RATE, not a forecast for this market: dispute (how often markets like this are disputed at UMA) by flip (when disputed, how often the outcome REVERSES). On-chain fact; a small cell is directional only."
  ],
  "concentration": {
    "distinctTraders": 349,
    "effectiveTraders": 18,
    "hhi": 0.06,
    "topTraderShare": 0.1425
  },
  "conditionId": "0xa3b36b2d6104d34af4e6c6215fc818e43352e78a748fbfb0b85e3a35f71dec9a",
  "dominantFlow": {
    "betResolvedInFavor": null,
    "counterpartyHhi": null,
    "distinctCounterparties": null,
    "effectiveCounterparties": null,
    "notionalUsd": 35760.11,
    "outcome": "Yes",
    "sampledFills": null,
    "side": "BUY",
    "vwap": 0.44,
    "wallet": "0x7d56d84778fc6caa66f517be0ebe1df5d9f54950",
    "walletMarkets": 1
  },
  "found": true,
  "marketClosed": false,
  "priceBand": {
    "nearResolutionShare": 0,
    "subCentShare": 0
  },
  "resolutionRisk": {
    "category": "Other",
    "categoryDisputeRatePct": 8.3,
    "categoryDisputeSample": "high-volume",
    "categoryElevated": false,
    "categoryFlipRatePct": 13.1,
    "categoryInsufficientSample": false,
    "flipInsufficientSample": false,
    "titleLooksCheckable": false
  },
  "structure": {
    "apparentVsBookFlag": false,
    "bookLiquidityUsd": 751513.2288,
    "endDate": "2026-09-16T00:00:00Z",
    "orderbookEnabled": true,
    "rewardsSubsidized": true,
    "spread": 0.01
  },
  "title": "Will there be no change in Fed interest rates after the September 2026 meeting?",
  "trades": 486,
  "windowHours": 71.95
}