HOW.IS● live
docs api console

Domain intelligence, priced per call. DNS, WHOIS, TLS, DNSSEC, email auth, blacklists and uptime — for humans with a card, and for AI agents that pay per request with no account at all.

What you can check

checkpricewhat you get
profile$0.025All 8 domain checks — dns, whois, tls, dnssec, email-auth, security-score, blacklist, plus ip resolved from the A record. $0.040 bought separately.
dns ●$0.005A/AAAA/MX/NS/TXT records + resolve timing
whois ●$0.005Registrar, dates, nameservers, status
tls ●$0.005Certificate validity, issuer, days remaining
dnssec ●$0.005Whether DNSSEC validates
email-auth ●$0.005SPF, DKIM and DMARC posture
security-score ●$0.005Overall security grade
blacklist ●$0.005Whether the domain/IP is listed
ip ●$0.005Intelligence for an IP address
bots$0.050Bot observatory, partner tier — networks, named crawlers, JA4 fingerprints, firewall rules, hourly series. One document, refreshed hourly.
site_status$0.005HTTP status + latency, DNS ms, TTL, NS, TLS expiry
page_watch$0.005Did this page change since last time, and by how much
● = included in the bundled profile call (8 of the 10 individual checks). site_status and page_watch stay separate: they need a URL and do a live fetch, and page_watch only means anything on a second call — though a profile now seeds its baseline for free.

Two ways to pay

No subscription and nothing expires — you buy a balance and spend it per call. $1 → 200 single checks or 40 full profiles; $10 → 2,000 or 400.

Humans → buy credits
Pay by card, get an API key with a prepaid balance. Every call draws it down.
Any amount from $1 — though $10+ wastes less on card fees.
Your API key:
Save it — it is your account.
Agents → pay per call (x402)
No signup, no key. Call it; get HTTP 402 with the price; pay in USDC; retry. Settles on Base (currently the Sepolia testnet).
$ curl -X POST https://how.is/v1/domain/whois \ -d '{"domain":"example.com"}' → 402 + PAYMENT-REQUIRED (price, asset, payTo) → agent signs & retries → data + settlement tx

For agents

door
/llms.txtEverything an agent needs on one page: checks, inputs, prices, how to pay. Full reference at /docs.md; OpenAPI 3.1 for codegen.
MCPRemote server at https://how.is/mcp — add it to Claude, Cursor or Codex with header Authorization: Bearer <key>. Every check is a tool.
Free samplesEach check runs free on its example input, no key: GET /v1/domain/whois?domain=example.com. See the real response before paying.
GET or POSTEvery check takes a JSON body or the same field as a query parameter. Bad input gets a 400 with the schema; nothing is charged.

Also available

feature
Bundled profileAll 8 domain checks in one call for $0.025 — you save 37% versus $0.040 buying them individually, and it is one payment instead of eight.
Scheduled monitorsWe re-check on your interval and record when a site goes down/recovers or a page materially changes. Funded from your balance.
Partial resultsIf a source is down we return the sections we got and name the ones we did not, in an errors field. The bundle is billed at its flat price either way — a profile is only refunded if every section fails. Individual checks are refunded when they fail.
Free watch baselineEvery profile call also stores a page snapshot of https://<domain> at no charge, so your first page_watch on it reports real changes instead of an empty first result. An existing baseline is never overwritten.
Page-change watchText-similarity diff vs the last snapshot — tells you how much changed and what.