Polymarket price history

Historical odds (implied probabilities) for a Polymarket outcome token. Returns timestamped price samples with first/last/min/max summary. Useful for: tracking probability shifts around events, computing realized volatility, backtesting prediction strategies.

Input

Field	Type	Description
tokenId *	string	CLOB token id (decimal string) from market.clobTokenIds.
interval	string	Lookback window: 1h, 6h, 1d, 1w, 1m, max (default 1d).
fidelity	number	Sample granularity in minutes (1-720, default 60).

Example output

{
  "tokenId": "72909...",
  "interval": "1d",
  "fidelityMinutes": 60,
  "count": 24,
  "min": 0.55,
  "max": 0.67,
  "first": 0.58,
  "last": 0.62,
  "points": [
    {
      "timestamp": 1751200000,
      "price": 0.58
    },
    {
      "timestamp": 1751203600,
      "price": 0.59
    }
  ],
  "source": "polymarket-clob"
}

Try it — see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/polymarket-price-history \
  -H "Content-Type: application/json" \
  -d '{"tokenId":"72909859729837290837290837290837290837290837290837290837290837290","interval":"1d"}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/polymarket-price-history", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "tokenId": "72909859729837290837290837290837290837290837290837290837290837290",
    "interval": "1d"
  }),
});

Wallet-only. This tool reaches the network/browser/storage, so it is paid in USDC via x402 (no proof-of-work tier).

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