The gap, per call.

Pricing

Unknown symbols return 404 before any payment is asked for. A failed lookup never costs anything.

Quickstart

Call any paid endpoint without payment and you get a 402 with the exact requirement:

curl -i https://parallax.pawww.sbs/v1/gap/NVDA

HTTP/2 402
payment-required: eyJ4NDAyVmVyc2lvbiI6Mi…   (base64 of the body below)

{ "x402Version": 2, "error": "payment_required",
  "accepts": [{ "scheme": "exact", "network": "eip155:4663",
    "amount": "2000", "asset": "0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168",
    "payTo": "<treasury>", "maxTimeoutSeconds": 120,
    "extra": { "name": "Global Dollar", "version": "1", "decimals": 6, "symbol": "USDG" } }] }

Sign an EIP-3009 TransferWithAuthorization for that amount to payTo, base64 the payload, and repeat the request with PAYMENT-SIGNATURE:

import { toHex } from "viem";
import { privateKeyToAccount } from "viem/accounts";

const agent = privateKeyToAccount(process.env.AGENT_KEY); // small wallet holding USDG
const url = "https://parallax.pawww.sbs/v1/gap/NVDA";

const { accepts: [req] } = await (await fetch(url)).json();          // 402
const message = {
  from: agent.address, to: req.payTo, value: BigInt(req.amount),
  validAfter: 0n, validBefore: BigInt(Math.floor(Date.now() / 1000) + 120),
  nonce: toHex(crypto.getRandomValues(new Uint8Array(32))),
};
const signature = await agent.signTypedData({
  domain: { name: "Global Dollar", version: "1", chainId: 4663, verifyingContract: req.asset },
  types: { TransferWithAuthorization: [
    { name: "from", type: "address" }, { name: "to", type: "address" },
    { name: "value", type: "uint256" }, { name: "validAfter", type: "uint256" },
    { name: "validBefore", type: "uint256" }, { name: "nonce", type: "bytes32" } ] },
  primaryType: "TransferWithAuthorization", message,
});
const payment = { x402Version: 2, accepted: req, payload: { signature, authorization: {
  ...message, value: String(message.value), validAfter: "0", validBefore: String(message.validBefore) } } };

const res = await fetch(url, { headers: { "PAYMENT-SIGNATURE": btoa(JSON.stringify(payment)) } });
console.log(await res.json());                        // the data
console.log(atob(res.headers.get("payment-response"))); // { success, transaction, network, payer }

The v1 header X-PAYMENT is accepted too. Standard x402 clients that support eip155:4663 and EIP-3009 work as-is.

Endpoints

{ "symbol": "NVDA", "name": "NVIDIA", "token": "0xd060…9EEC",
  "onchain_usd": 230.89, "reference_usd": 230.56,
  "reference_source": "chainlink", "reference_updated_at": "2026-09-29T14:02:11.000Z",
  "gap_pct": 0.14, "gap_bps": 14,
  "pool": { "id": "0xd4eb…", "venue": "uniswap v3", "depth_usd": 5272424 },
  "observed_at": "2026-09-29T14:06:00.000Z", "us_market_session": "regular",
  "method": "gap = (on-chain pool price − reference) / reference. …" }

How payment works

1. 01

   You sign

   An EIP-3009 authorization moving exactly the price in USDG from your wallet to the PARALLAX treasury. No gas, no approval, no custody.

2. 02

   We check

   Signature, amount, recipient, time window, balance and nonce, before anything touches the chain. Each nonce is claimed once; replays are refused.

3. 03

   We settle

   Our relayer submits the transfer and pays the gas. The response carries PAYMENT-RESPONSE with the transaction hash.

MCP

curl -o parallax-mcp.mjs https://parallax.pawww.sbs/mcp/parallax-mcp.mjs

{
  "mcpServers": {
    "parallax": {
      "command": "node",
      "args": ["/path/to/parallax-mcp.mjs"],
      "env": {
        "PARALLAX_PAYER_KEY": "0x… (agent wallet, USDG only)",
        "PARALLAX_MAX_SPEND": "1.00"
      }
    }
  }
}

claude mcp add parallax -e PARALLAX_PAYER_KEY=0x… -e PARALLAX_MAX_SPEND=1 -- node /path/to/parallax-mcp.mjs

claude mcp add --transport http parallax https://parallax.pawww.sbs/mcp

Notes