Listing Guard
by api.spendpreflight.com in Other
Bazaar Listing Guard: CDP technical validation plus a bounded heuristic metadata screen for agent-directed instructions, embedded URLs, tool calls, invisible Unicode, long fields and prices above 100x a fresh Scout category median. Returns riskScore, flagged spans and rewrite suggestions. Not Coinbase policy certification or guaranteed detection. Public HTTPS only; no target payment or request bodies stored.
https://api.spendpreflight.com/listing-guard- Price
- $0.05
- per call in USDC
- Uptime
- 100%
- last 30 days
- Response time
- 504 ms
- 551 ms slowest 5%
- Last check
- Passed
- 4 h ago, next any minute now
Reliability
Status and outage history · Atom feed · Watch with other listings
How to call it
POST https://api.spendpreflight.com/listing-guard
Each call costs $0.05 in USDC on Base, 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.
POST https://api.spendpreflight.com/listing-guard
content-type: application/json
{
"method": "GET",
"url": "https://api.spendpreflight.com/v1/check"
}Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
method | string | Yes | One of: GET, HEAD, POST. |
url | string (uri) | Yes |
Example response
The listing has no example response.
Call it from code
The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.05.
curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.spendpreflight.com/listing-guard' \
-H 'content-type: application/json' \
--data-raw '{"method":"GET","url":"https://api.spendpreflight.com/v1/check"}'
# 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 - -X POST 'https://api.spendpreflight.com/listing-guard' \
-H 'content-type: application/json' \
--data-raw '{"method":"GET","url":"https://api.spendpreflight.com/v1/check"}' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.spendpreflight.com%2Flisting-guard&method=POST
const res = await pay("https://api.spendpreflight.com/listing-guard", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"method": "GET",
"url": "https://api.spendpreflight.com/v1/check"
}),
});
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))
with x402_requests(client) as session:
res = session.post(
"https://api.spendpreflight.com/listing-guard",
json={
"method": "GET",
"url": "https://api.spendpreflight.com/v1/check",
},
)
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
| When | Result | HTTP | Time | Price |
|---|---|---|---|---|
| 4 h ago | Passed | 402 | 551 ms | $0.05 |
| 10 h ago | Passed | 402 | 363 ms | $0.05 |
| 15 h ago | Passed | 402 | 328 ms | $0.05 |
| 20 h ago | Passed | 402 | 511 ms | $0.05 |
| 25 h ago | Passed | 402 | 504 ms | $0.05 |
Show 2 older checks
| 30 h ago | Passed | 402 | 502 ms | $0.05 |
| 35 h ago | Passed | 402 | 533 ms | $0.05 |