ToolVet
80trust / 100

Nonce Hex

by Delx Nonce Hex in Onchain & crypto

x402 APIPassing, checked 21 min ago

Generate a random hex nonce. Call when you need request nonces for agent idempotency keys. Returns hex nonce and byte length for $0.001 USDC via x402 on Base. No network, no keys, no retention; first-party local JSON only. Results are advisory; the caller owns budgets, auth, and production controls.

POST
https://api.delx.ai/api/v1/x402/nonce-hex
Price
$0.001
per call in USDC
Uptime
100%
last 30 days
Response time
9 ms
73 ms slowest 5%
Last check
Passed
21 min ago, next in 9 min

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

POST https://api.delx.ai/api/v1/x402/nonce-hex

Each call costs $0.001 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.delx.ai/api/v1/x402/nonce-hex
content-type: application/json

{
  "bytes": 8
}

Parameters

ParameterTypeRequiredDescription
bytesintegerNoInput field: bytes.

Example response

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

{
  "bytes": 8,
  "hex": "ba2339cc6566e507",
  "schema": "delx/util-nonce-hex/v1"
}

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.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.delx.ai/api/v1/x402/nonce-hex' \
  -H 'content-type: application/json' \
  --data-raw '{"bytes":8}'

# 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.delx.ai/api/v1/x402/nonce-hex' \
  -H 'content-type: application/json' \
  --data-raw '{"bytes":8}' \
  | 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%2Fapi.delx.ai%2Fapi%2Fv1%2Fx402%2Fnonce-hex&method=POST
const res = await pay("https://api.delx.ai/api/v1/x402/nonce-hex", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "bytes": 8
  }),
});
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.post(
        "https://api.delx.ai/api/v1/x402/nonce-hex",
        json={
            "bytes": 8,
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
21 min agoPassed40224 ms$0.001
4 h agoPassed4029 ms$0.001
9 h agoPassed40273 ms$0.001
13 h agoPassed40227 ms$0.001
17 h agoPassed4026 ms$0.001
Show 10 older checks
21 h agoPassed4027 ms$0.001
26 h agoPassed4027 ms$0.001
30 h agoPassed4027 ms$0.001
34 h agoPassed40229 ms$0.001
38 h agoPassed40225 ms$0.001
42 h agoPassed4028 ms$0.001
46 h agoPassed4029 ms$0.001
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2 days agoPassed4027 ms$0.001