ToolVet
75trust / 100

Attest Preflight

by numberintel.dev in Documents & files

x402 APIPassing, checked 2 h ago

x402 conformance preflight of any endpoint: parses the 402 envelope, lints accepts[] (atomic units, payTo, network), reports the quote, Bazaar extension presence and problems. No purchase is made.

GET
https://numberintel.dev/v1/attest/preflight
Price
$0.02
per call in USDC
Uptime
100%
last 30 days
Response time
553 ms
621 ms slowest 5%
Last check
Passed
2 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

How to call it

GET https://numberintel.dev/v1/attest/preflight

Each call costs $0.02 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.

GET https://numberintel.dev/v1/attest/preflight?target=https%3A%2F%2Fapi.onesource.io%2Fapi%2Fchain%2Fblock-number

Parameters

ParameterTypeRequiredDescription
methodstringNoGET or POST, default GET
targetstringYeshttps URL of the x402 endpoint to check

Example response

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

{
  "accepts_count": 2,
  "base_mainnet_option": true,
  "grade": "quote_ok",
  "has_bazaar_extension": true,
  "http_status": 402,
  "latency_ms": 414,
  "method": "GET",
  "problems": [],
  "quote": {
    "amount_atomic": "1000",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "network": "eip155:8453",
    "payTo": "0x52E29e0d2Aa49bfBfC548C0A9F2196F4aa51f3ea",
    "usd": 0.001
  },
  "reachable": true,
  "target": "https://api.onesource.io/api/chain/block-number",
  "x402_version": 2
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.02.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://numberintel.dev/v1/attest/preflight?target=https%3A%2F%2Fapi.onesource.io%2Fapi%2Fchain%2Fblock-number'

# 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://numberintel.dev/v1/attest/preflight?target=https%3A%2F%2Fapi.onesource.io%2Fapi%2Fchain%2Fblock-number' \
  | 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 $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
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 $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fnumberintel.dev%2Fv1%2Fattest%2Fpreflight
const res = await pay("https://numberintel.dev/v1/attest/preflight?target=https%3A%2F%2Fapi.onesource.io%2Fapi%2Fchain%2Fblock-number");
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 $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://numberintel.dev/v1/attest/preflight?target=https%3A%2F%2Fapi.onesource.io%2Fapi%2Fchain%2Fblock-number")
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
2 h agoPassed402565 ms$0.02
6 h agoPassed402553 ms$0.02
11 h agoPassed402197 ms$0.02
15 h agoPassed402183 ms$0.02
19 h agoPassed402543 ms$0.02
Show 3 older checks
23 h agoPassed402621 ms$0.02
27 h agoPassed402601 ms$0.02
31 h agoPassed402804 ms$0.02