ToolVet
71trust / 100

X402 Echo

by P0 x402 Market Index in Markets & finance

x402 APIPassing, checked 5 h ago

Use for debugging an x402 client: pay $0.001 in USDC (or USDT0 on Arbitrum) on any network in accepts and get back what the server received: the decoded payment payload (scheme, network, authorization fields, signature), checks of amount, payTo, asset and validity window against this route's requirement, and the facilitator's settlement result. Only the payment header is echoed, never other headers.

GET
https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo
Price
$0.001
per call in USDC
Uptime
100%
last 30 days
Response time
970 ms
1.2 s slowest 5%
Last check
Passed
5 h ago, next any minute now

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo

Each call costs $0.001 in USDC on Optimism, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo

Example response

The provider's example. We can't check it without paying.

Example response, 50 lines
{
  "checks": {
    "amountMatches": true,
    "assetMatches": true,
    "decoded": true,
    "network": "eip155:8453",
    "payToMatches": true,
    "scheme": "exact",
    "validAfter": "2026-10-04T11:59:00.000Z",
    "validBefore": "2026-10-04T12:05:00.000Z",
    "withinWindow": true,
    "x402Version": 2
  },
  "header": {
    "bytes": 824,
    "encoding": "base64-json",
    "name": "payment-signature"
  },
  "ok": true,
  "payment": {
    "accepted": {
      "amount": "1000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "network": "eip155:8453",
      "payTo": "0xECa891e34b3E5873181Fb779672564E198C55354",
      "scheme": "exact"
    },
    "payload": {
      "authorization": {
        "from": "0x7EF12BE6000000000000000000000000000000aa",
        "nonce": "0xefefefefefefefefefefefefefefefefefefefefefefefefefefefefefefefef",
        "to": "0xECa891e34b3E5873181Fb779672564E198C55354",
        "validAfter": "1791115140",
        "validBefore": "1791115500",
        "value": "1000"
      },
      "signature": "0xcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcdcd"
    },
    "x402Version": 2
  },
  "route": "/x402-echo",
  "settle": {
    "facilitator": "coinbase-cdp",
    "network": "eip155:8453",
    "payer": "0x7EF12BE6000000000000000000000000000000aa",
    "success": true,
    "transaction": "0xabababababababababababababababababababababababababababababababab"
  },
  "ts": "2026-10-04T12:00:00.000Z"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.001.

The code pays $0.001 in USDC on Base instead: the x402 libraries don't pay USDC by default.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.001 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.001" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.001 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fx402-bazaar-rank.x402-bazaar-rank-worker.workers.dev%2Fx402-echo
const res = await pay("https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo");
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.001 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.001"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402-echo")
    print(res.status_code, res.text)

Security scan

No findings

We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
5 h agoPassed4021.1 s$0.001
9 h agoPassed40261 ms$0.001
14 h agoPassed4021.2 s$0.001
19 h agoPassed402970 ms$0.001
23 h agoPassed402316 ms$0.001
Show 2 older checks
27 h agoPassed40258 ms$0.001
36 h agoPassed4021.2 s$0.001