X402/REGISTERas of 07-21 11:47 UTC

domain-availability-checker.underscoredone.com

96.9 / 100 · rank 78 of 1519

last 120 hours · short tick = valid 402 · full tick = invalid or no answer · faint = not probed

score components (0-100) · not the raw measurements below

Availability93

Latency100

Price integrity100

Protocol100

Consistency100

Availability is the one component that is a success rate, so it alone carries an evidence discount: it enters as the 95% Wilson lower bound of the measured share (cubed), which is why its bar reads below the raw percentage above — thin evidence scores below a long proven record. Latency, price, protocol and consistency are direct measurements, shown as-is.

Availability (valid 402 returned)	100.0% of 160 probes
Median 402 handshake	183ms
p90 handshake	193ms
Catalog price (advertised)	$0.01
Live price (median demanded)	$0.01
Price status	match
Protocol	x402 v2
Category (our classification)	other
Payment receiver	0xE974…2F08 (+1 more) · stable since Jul 12
Base USDC inflow to this receiver wallet (30d, all sources — not just x402)	shared receiver wallet — total inflow is not attributable to this domain alone
Second vantage	confirmed 402 from a second network path (Cloudflare edge), 7h ago
Discovery (.well-known/x402)	not found
Catalog volume (their metric)	3 calls/30d

Seller-provided description · unverified · not part of the rating

Give this API up to 10 domain names and it will tell you whether each one has a registration record on file with the official registry. It uses RDAP — the modern, structured replacement for WHOIS — so there is no messy free-text parsing. Each domain comes …

Embed this grade (free, always current)

<a href="https://x402register.com/s/domain-availability-checker.underscoredone.com.html"><img src="https://x402register.com/badge/domain-availability-checker.underscoredone.com.svg" alt="x402 register grade A"></a>

What this grade does and doesn't measure: it scores the paid-request handshake — whether the service returns a spec-valid 402 payment challenge, how fast, and whether its price is honest. We do not pay these endpoints yet, so we do not verify that the paid response returns correct or complete content. Availability is a probe success rate measured hourly, corroborated by a second network path for this service.

Operator of domain-availability-checker.underscoredone.com? Dispute this rating. Scores are opinions based on automated measurements at the stated times.