Domaincheck Email

{
  "canonical": "[email protected]",
  "deliverability": {
    "accepts_mail": true,
    "domain_exists": true,
    "mx": [
      {
        "host": "gmail-smtp-in.l.google.com",
        "priority": 5
      },
      {
        "host": "alt1.gmail-smtp-in.l.google.com",
        "priority": 10
      },
      {
        "host": "alt2.gmail-smtp-in.l.google.com",
        "priority": 20
      },
      {
        "host": "alt3.gmail-smtp-in.l.google.com",
        "priority": 30
      },
      {
        "host": "alt4.gmail-smtp-in.l.google.com",
        "priority": 40
      }
    ],
    "mx_provider": "Google Workspace / Gmail",
    "null_mx": false
  },
  "disposable": false,
  "dns_queries": 6,
  "domain": "gmail.com",
  "domain_auth": {
    "dmarc": "none",
    "grade": "D",
    "spf": "redirect"
  },
  "engine": "domaincheck-2026.10.21",
  "flags": [
    {
      "description": "Free webmail provider (gmail.com, outlook.com ...).",
      "id": "free_email_provider",
      "penalty": 0,
      "severity": "info"
    },
    {
      "description": "DMARC policy is p=none (monitoring only, no enforcement).",
      "id": "dmarc_none",
      "penalty": 5,
      "severity": "low"
    }
  ],
  "free_provider": true,
  "input": "[email protected]",
  "local": "jane.doe+news",
  "mailbox_checked": false,
  "ms": 40,
  "normalized": "[email protected]",
  "note": "Mailbox existence is not probed (no SMTP RCPT check). \"valid\" means the address is well-formed, the domain accepts mail and nothing looks risky.",
  "plus_tag": "news",
  "registration": null,
  "role": false,
  "score": 95,
  "smtputf8": false,
  "syntax": {
    "reason": null,
    "valid": true
  },
  "tier": "full",
  "verdict": "valid"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.youraitools.co/domaincheck/v1/email?email=jane.doe%2Bnews%40gmail.com'

# 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://api.youraitools.co/domaincheck/v1/email?email=jane.doe%2Bnews%40gmail.com' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// 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.youraitools.co%2Fdomaincheck%2Fv1%2Femail
const res = await pay("https://api.youraitools.co/domaincheck/v1/email?email=jane.doe%2Bnews%40gmail.com");
console.log(res.status, await res.text());

# 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://api.youraitools.co/domaincheck/v1/email?email=jane.doe%2Bnews%40gmail.com")
    print(res.status_code, res.text)