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 / seller-trust

Check an x402 seller's trust evidence

FREE with proof-of-work · or $0.005 in USDC · GET /api/x402/seller-trust

Trust evidence for any x402 seller origin: is it indexed, does its manifest parse, how many tools does it publish, which chains does it actually advertise, how many settled calls has it been observed receiving on-chain, and would our own Smart Order Router spend buyer money on it. Returns the router's gate field by field, so a refusal is explainable. Never fetches the seller at call time - this is our accumulated crawl and settlement evidence, not a liveness probe.

Input

FieldTypeDescription
origin *stringSeller origin or bare host, e.g. https://example.com or example.com

Example output

{}

Try it - see the 402 challenge (free)

curl -i "https://agent402.tools/api/x402/seller-trust?origin=agent402.tools"

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/x402/seller-trust?origin=agent402.tools");

No wallet? Pay with compute

This is a pure-CPU tool, so an agent without a wallet can pay with proof-of-work instead of USDC: fetch a challenge, solve the sha256 puzzle (16 leading zero bits - a fraction of a second of CPU, no money, no AI tokens), and resend with the X-Pow-Solution header.

import { createHash } from "node:crypto";
const lz = (b) => { let t = 0; for (const x of b) { if (!x) { t += 8; continue; } t += Math.clz32(x) - 24; break; } return t; };
const c = await (await fetch("https://agent402.tools/api/pow/challenge?slug=seller-trust")).json();
let n = 0;
while (lz(createHash("sha256").update(c.challenge + ":" + n).digest()) < c.difficulty) n++;
await fetch("https://agent402.tools/api/x402/seller-trust", { method: "GET", headers: { "X-Pow-Solution": c.token + ":" + n } });

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