email-preflight-api.vercel.app

88.9 / 100 · rank 1291 of 1571

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

Availability83

Latency76

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 62 probes
Median 402 handshake	410ms
p90 handshake	2763ms
Catalog price (advertised)	$0.003
Live price (median demanded)	$0.003
Price status	match
Protocol	x402 v2
Category (our classification)	commerce-payments
Payment receiver	0x8331…064D · stable since Jul 12
Base USDC inflow to this receiver wallet (30d, all sources — not just x402)	none observed
Second vantage	confirmed 402 from a second network path (Cloudflare edge), 1h ago
Discovery (.well-known/x402)	present
Catalog volume (their metric)	1 calls/30d

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

Pre-action check for AI agents: inspect an unfamiliar live x402 v2 challenge immediately before purchase. Verify price, network, payee, resource binding, timeout, and Bazaar metadata without paying the target or forwarding credentials. POST probes send …

Embed this grade (free, always current)

<a href="https://x402register.com/s/email-preflight-api.vercel.app.html"><img src="https://x402register.com/badge/email-preflight-api.vercel.app.svg" alt="x402 register grade B"></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 email-preflight-api.vercel.app? Dispute this rating. Scores are opinions based on automated measurements at the stated times.