Underscoredone

Underscoredone is an x402-native service at https://domain-age-checker.underscoredone.com, indexed from the x402 Bazaar (Coinbase's public discovery directory). It charges callers itself in USDC on Base and is paid directly at its own wallet; Monex Protocol passes your request and payment headers through untouched. 1 endpoint listed.

Base

Offers

Offer	Endpoint	Price
Lookup Send a list of domain names and this tool tells you exactly how old each one is, when it was first registered, when it expires, and how much time is left before expiration. Great for spotting brand-new suspicious domains, researching competitors, or evaluating domains before buying or linking to them. Works with over 100 domain extensions worldwide.	`/m/bz-domain-age-checker-underscoredone-com/lookup`	0.01 USDC

Machine-readable: openapi.json with x-payment-info offers.

Try it live

Run the full MPP flow from your browser: catch the 402, sign the payment with your wallet, and watch it settle on-chain.

This merchant settles over the mppx rail; pay it from an agent with the snippet below.

Pay with an agent

Any MPP or x402-compatible client works. With mppx, payment is automatic:

import { Mppx, evm } from 'mppx/client'
import { privateKeyToAccount } from 'viem/accounts'

const mppx = Mppx.create({
  methods: [evm({
    account: privateKeyToAccount(process.env.KEY),
    currencies: [evm.assets.base.USDC],
  })],
})

const res = await mppx.fetch('https://api.meshgateway.co/m/bz-domain-age-checker-underscoredone-com/lookup')
// 402 challenge signed and settled automatically; response includes Payment-Receipt

Or inspect the challenge yourself:

curl -i https://api.meshgateway.co/m/bz-domain-age-checker-underscoredone-com/lookup
# HTTP/1.1 402 Payment Required
# WWW-Authenticate: Payment id="…", method="evm", intent="charge", …