HTTP/1.1 402 PAYMENT REQUIRED agent402.base.eth · BASE · SOLANA · POLYGON · ARBITRUM · MONAD · CELO · AVALANCHE · SEI · OPTIMISM · STELLAR · ALGORAND · ROBINHOOD · USDC · USDG
Agent402 / tools / polymarket-orderbook

Polymarket orderbook

$0.002 per call · USDC via x402 · POST /api/polymarket-orderbook

Live CLOB orderbook for a Polymarket outcome token. Returns top N bids (highest first), top N asks (lowest first), best bid/ask, mid-price, and spread. Use a clobTokenId from polymarket-market or polymarket-search.

Input

FieldTypeDescription
tokenId *stringCLOB token id (decimal string) from market.clobTokenIds.
depthnumberLevels each side to return (1-50, default 10).

Example output

{
  "tokenId": "72909...",
  "market": "0xabc...",
  "asset": "72909...",
  "timestamp": "1751234567",
  "bestBid": 0.61,
  "bestAsk": 0.63,
  "midPrice": 0.62,
  "spread": 0.02,
  "bids": [
    {
      "price": 0.61,
      "size": 1000
    },
    {
      "price": 0.6,
      "size": 500
    }
  ],
  "asks": [
    {
      "price": 0.63,
      "size": 800
    },
    {
      "price": 0.64,
      "size": 1200
    }
  ],
  "source": "polymarket-clob"
}

Try it - see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/polymarket-orderbook \
  -H "Content-Type: application/json" \
  -d '{"tokenId":"60447443643099453130956385288904175887233107411078568881602330835010340506057","depth":5}'

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-orderbook", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "tokenId": "60447443643099453130956385288904175887233107411078568881602330835010340506057",
    "depth": 5
  }),
});
Wallet-only. This tool reaches the network/browser/storage, so it is paid in USDC via x402 (no proof-of-work tier).

Related tools

Crypto order book

$0.003 · GET /api/crypto-orderbook

L2 order-book snapshot for a spot pair: best bid/ask, mid price, spread (absolute + %), and the top N aggregated price l…

Stablecoin peg monitor

$0.003 · GET /api/stablecoin-peg

Live $1-peg deviation for the top USD stablecoins (USDT, USDC, USDS, DAI, USDe, PYUSD, USDD, TUSD, FDUSD by default, or …

Wallet balance (native + ERC-20)

$0.002 · POST /api/wallet-balance

Look up the native coin balance (ETH/MATIC) plus every ERC-20 holding for a wallet address on Ethereum, Base, Polygon, A…