WHOIS and domain APIs you can pay per call

What WHOIS APIs do

A WHOIS API returns the registration record of a domain name: the registrar that manages it, the dates it was created, last updated and set to expire, its status codes and the nameservers it delegates to. Agents use these records to vet a sender or a link, to watch a portfolio for renewals, to check a counterparty's website before paying, or to see whether a name could be registered.

Two protocols carry this data. WHOIS is the older one: a text answer whose layout differs from registry to registry. RDAP, the Registration Data Access Protocol, returns structured JSON with standard field names and links between registry and registrar records. For generic top-level domains, ICANN made RDAP the definitive source of registration data in 2025, while country-code registries set their own rules. A parsed answer saves work; a raw answer keeps the registry's own wording.

A registration record is not an ownership certificate. Since privacy laws such as the GDPR took effect, registrant names, emails and addresses are frequently redacted or replaced by a privacy service. What remains reliable is the registry's view of the registrar, the dates, the status and the delegation. Treat a named registrant as a claim made at registration, not as verified identity.

Registries limit query rates and can refuse automated bulk access. A paid API wraps those lookups and may cache answers; it does not change the registry's terms. Keep the time of each answer, and refresh before an action that depends on a date or a status.

Compare registration records and related domain data

The comparison separates five outputs. A registration record comes from WHOIS or RDAP and names the registrar, dates, status or nameservers. DNS results show what resolvers answer for the name, including DNSSEC and propagation checks. Certificate data describes the TLS certificate a host serves or has been issued. A domain age check returns how long ago a name was created. An availability check says whether a name is registered or could be.

A row needs a fixed quote for a registration record. DNS, certificate, age and availability results are adjacent types: they can accompany a qualifying service but cannot bring a service into the table or set its price. A domain bundle that returns registration data together with DNS and certificate facts counts for each type it returns.

Domain words also appear in other products. An email-authentication audit grades SPF, DKIM and DMARC for a sending domain. An uptime or health score tests reachability. A WHOIS lookup for an autonomous system describes a network, not a domain. Reverse DNS starts from an IP address. A list of subdomains from certificate logs is reconnaissance, not registration data. These products stay outside the table.

Matched endpoint descriptions from NetIntel, DNS & WHOIS Domain Lookup, IPIntel.ai x402 Tools, API Acre, Datakoot, Scribe, x402.eleeth.com, x402 Web Probe, fetchx402, OrionCMD Site Checks and agosint name RDAP as a source. Matched endpoint descriptions from DNS & WHOIS Domain Lookup and grist.tools return the raw WHOIS response next to or instead of parsed fields. Matched endpoint descriptions from IPIntel.ai x402 Tools flag privacy or redaction in the record.

Matched endpoint descriptions from NetIntel, DNS & WHOIS Domain Lookup, API Acre, fetchx402, OrionCMD Site Checks and agosint name DNSSEC. Matched endpoint descriptions from NetIntel, Datakoot and OrionCMD Site Checks resolve names over DNS-over-HTTPS. Matched endpoint descriptions from NetIntel and OrionCMD Site Checks read Certificate Transparency logs, which list issued certificates rather than the one a host serves.

Each price is the cheapest endpoint of that service for that kind of data: the same number wherever this page quotes it.

Compare 13 WHOIS data services

Each row keeps the selected registration endpoint and its reference quote. The ordering follows observed paying wallets for the service; it does not rank record accuracy or registry coverage.

$/CALL is the price of the endpoint named under it: the cheapest domain registration record from whois or rdap: registrar, dates, status or nameservers endpoint of the service or, for a service without one, its cheapest domain endpoint. Never the cheapest tool of a gateway. Other kinds of data have their own price in the tables below. DOMAIN ENDPOINTS counts the domain endpoints out of all the endpoints the service lists. BUYERS 30D counts distinct wallets that paid the whole service on-chain in 30 days, not only its domain endpoints. "Generalist" marks a gateway that sells more than three unrelated kinds of tools: it is never called the cheapest.

How to choose a WHOIS endpoint

Decide between raw and parsed records

Parsed RDAP fields are easier to store and compare. Raw WHOIS text keeps details a parser can drop and covers registries without a public RDAP service. If the agent makes decisions on a field such as the expiry date, read the raw answer for a sample of the extensions you care about and compare it with the parsed one.

Check the extensions you need

Coverage differs by registry. Test the country-code extensions your users rely on, because their registries publish different fields, apply different privacy rules and may not offer RDAP at all.

Read status codes, not only dates

Status codes such as a transfer lock, a pending delete or a server hold say more about a domain's situation than its expiry date. A renewal can move the expiry date, and the registry and the registrar can briefly show different dates.

Treat contact data as optional

Plan for redacted registrant fields. A workflow that needs the owner of a domain should use other evidence, such as the website, the company register or a direct contact through the registrar's relay.

Keep bundles for real needs

A domain report that combines registration, DNS and certificate facts saves several calls, but each part can fail on its own. Prefer a bundle that marks a failed part as missing, and pay for a single lookup when one field is all the agent needs.

Test the operating limits

The monitored median uptime is 100% and the median selected quote is $0.005. Monitoring latency measures our checks of the service, not how long a registry takes to answer. Run real lookups across your extensions and measure response time, refusals and empty fields.

Choose by the output your workflow needs

Start with the output the next step consumes. The candidates below use the same type classification as the comparison table, and each job quote belongs to the lowest priced endpoint of its requested types, with the path kept.

Read a domain's registration record

Keep the query time with the record. Registrar, dates and status can change after a transfer or renewal, and contact fields are often redacted, so a record rarely names the person behind a domain.

Candidates today, most buyers first: Domain Intelligence API ($0.02/call, 312 buyers) · NetIntel ($0.003/call, generalist, 100 buyers) · DNS & WHOIS Domain Lookup ($0.005/call, 32 buyers) · IPIntel.ai x402 Tools ($0.005/call, 25 buyers) · API Acre ($0.02/call, generalist, 20 buyers) · Datakoot ($0.01/call, generalist, 7 buyers) · Scribe ($0.005/call, generalist, 6 buyers) · x402 Web Probe ($0.002/call, 1 buyer) · x402.eleeth.com ($0.01/call, generalist, 1 buyer) · grist.tools ($0.002/call) · fetchx402 ($0.005/call) · OrionCMD Site Checks ($0.01/call) · agosint ($0.015/call, generalist)

Resolve DNS records or check DNSSEC

DNS answers depend on the resolver and the moment of the query. Keep the record type, the answer and its TTL, and query again after a change instead of trusting a cached answer.

Candidates today, most buyers first: Domain Intelligence API ($0.02/call, 312 buyers) · NetIntel ($0.002/call, generalist, 100 buyers) · DNS & WHOIS Domain Lookup ($0.005/call, 32 buyers) · IPIntel.ai x402 Tools ($0.001/call, 25 buyers) · API Acre ($0.02/call, generalist, 20 buyers) · Datakoot ($0.01/call, generalist, 7 buyers) · Scribe ($0.005/call, generalist, 6 buyers) · x402 Web Probe ($0.002/call, 1 buyer) · x402.eleeth.com ($0.01/call, generalist, 1 buyer) · fetchx402 ($0.005/call) · OrionCMD Site Checks ($0.01/call) · agosint ($0.015/call, generalist)

Check the certificate a host presents

A certificate log shows what was issued; a live handshake shows what the host serves now. Check which one the route reads before relying on an expiry date.

Candidates today, most buyers first: Domain Intelligence API ($0.02/call, 312 buyers) · NetIntel ($0.003/call, generalist, 100 buyers) · API Acre ($0.02/call, generalist, 20 buyers) · Scribe ($0.005/call, generalist, 6 buyers) · x402 Web Probe ($0.002/call, 1 buyer) · grist.tools ($0.002/call) · fetchx402 ($0.005/call) · OrionCMD Site Checks ($0.01/call) · agosint ($0.015/call, generalist)

Judge how long a domain has existed

A creation date can describe the latest registration, not the first. A name that expired and was registered again starts a new date, and an archive estimate is not a registry fact.

Candidates today, most buyers first: Domain Intelligence API ($0.02/call, 312 buyers) · NetIntel ($0.003/call, generalist, 100 buyers) · DNS & WHOIS Domain Lookup ($0.005/call, 32 buyers) · IPIntel.ai x402 Tools ($0.005/call, 25 buyers) · API Acre ($0.02/call, generalist, 20 buyers) · Datakoot ($0.01/call, generalist, 7 buyers) · Scribe ($0.005/call, generalist, 6 buyers) · x402 Web Probe ($0.002/call, 1 buyer) · x402.eleeth.com ($0.01/call, generalist, 1 buyer) · grist.tools ($0.002/call) · fetchx402 ($0.005/call) · OrionCMD Site Checks ($0.01/call) · agosint ($0.015/call, generalist)

Check whether a name can be registered

A missing record suggests a name is free, but reserved, premium or recently deleted names can still be unavailable. Confirm with a registrar before promising a name to anyone.

Candidates today, most buyers first: NetIntel ($0.01/call, generalist, 100 buyers) · IPIntel.ai x402 Tools ($0.002/call, 25 buyers)

What the providers describe

These paragraphs attribute record fields, sources and failure behavior to the provider that documents them. Reference prices follow the matching endpoint type, never an amount written in a marketing description.

NetIntel

NetIntel lists GET /whois-rdap/lookup from $0.003. The endpoint description says it returns registrar, registration and expiry dates, last-updated date, nameservers and status flags from the authoritative registry, plus an actionability score of its own. DNS routes, DNSSEC validation and propagation checks start at $0.002. A separate age check tries RDAP, then port-43 WHOIS, then an estimate from Wayback captures, and reports which source it used. Availability checks start at $0.01; the bulk check warns that a name reads as available when both RDAP and DNS are unreachable. The gateway lists 124 endpoints, including IP and text tools at their own prices.

13 domain endpoints of 124 · $0.003/call (GET /whois-rdap/lookup) · Base/SOL · uptime 30d 100% · 107 ms · 100 buyers in 30 days

DNS & WHOIS Domain Lookup

DNS & WHOIS Domain Lookup separates the raw and the parsed record. GET /whois returns the registry text with the responding server, and GET /rdap returns structured registrar, dates, status and nameservers with a computed domain age; registration data starts at $0.005. A, MX and TXT lookups and a DNSSEC check start at $0.005. The provider points to the RDAP route when parsed data is needed.

6 domain endpoints of 6 · $0.005/call (GET /rdap) · ARB/Base/POL/SOL · uptime 30d 100% · 368 ms · 32 buyers in 30 days

fetchx402

fetchx402 lists GET /v1/tools/whois, a WHOIS lookup via RDAP with registrar, status, dates, nameservers and DNSSEC, from $0.005. The endpoint description says unregistered names return not_found. A host-intel bundle combines DNS, the leaf certificate and WHOIS/RDAP for one hostname in a single payment, and the provider says child errors stay in their field rather than being filled with guessed data. DNS tools start at $0.005 and certificate tools at $0.005.

4 domain endpoints of 7 · $0.005/call (GET /v1/tools/whois) · Base · uptime 30d 100% · 1007 ms · 0 buyers in 30 days

OrionCMD Site Checks

OrionCMD Site Checks lists GET /v1/expiry from $0.01: registrar, registration and expiry dates, days left, EPP status and nameservers from the registry's RDAP server. Within 60 days of expiry, the provider says the answer adds auto-renew steps for the detected registrar. Its certificate check, from $0.01, combines Certificate Transparency logs with a live HTTPS probe, and the description notes that the log data is not the certificate the host serves.

4 domain endpoints of 4 · $0.01/call (GET /v1/expiry) · Base · uptime 30d 100% · 284 ms · 0 buyers in 30 days

Datakoot

Datakoot lists registration intelligence via RDAP and a domain dossier that combines registration, DNS records, email deliverability and the website technology stack, from $0.01. Its DNS lookup uses Cloudflare DNS-over-HTTPS, from $0.01. The endpoint descriptions say calls are charged only on success. The same gateway sells public-data tools on security, filings and the economy at their own prices.

3 domain endpoints of 48 · $0.01/call (GET /api/domain_intel) · Base · uptime 30d 100% · 86 ms · 7 buyers in 30 days

IPIntel.ai x402 Tools

IPIntel.ai x402 Tools lists POST /whois-lookup from $0.005. The description names registrar, WHOIS server, creation, expiration and updated dates, nameservers, domain status and privacy or redaction signals. An availability check, from $0.002, uses RDAP registry data with DNS fallback signals and returns a machine-readable availability verdict.

3 domain endpoints of 10 · $0.005/call (POST /whois-lookup) · Base · uptime 30d 100% · 256 ms · 25 buyers in 30 days

Scribe

Scribe sells one domain lookup from $0.005: RDAP registration data, live DNS records, the TLS certificate served at the name and what the HTTP front door returns, in one JSON answer. The service description says each part is best effort with an errors map, so a missing part is reported rather than hidden. The provider says the route avoids rate-limited WHOIS.

1 domain endpoint of 4 · $0.005/call (GET /v1/domain) · Base/SOL · uptime 30d 99.8% · 275 ms · 6 buyers in 30 days

Cost per lookup and for a larger workload

The median selected route has a reference quote of $0.005 per call. At the same request shape, 100,000 calls would total $500.00. Use the generated table as a reference calculation for lookups, then count how many calls one finished task needs.

Each service at the price of its main domain endpoint, the one named in the table above.

A vetting task can take more than one call: a registration record, a DNS check and a certificate check, or a bundle that combines them. A portfolio monitor repeats the same lookups on a schedule. Count the calls per decision and per domain per month, and cache answers for as long as the decision allows, since registration data changes slowly between renewals.

Set a budget per task and a stopping rule for retries. Separate a not-found answer, a registry refusal and a successful record in your records, because a provider may charge them differently. Read the quote for the exact request before authorizing a payment.

Inspect a request and its payment evidence

For a parsed registration record, DNS & WHOIS Domain Lookup documents GET /rdap. Read the current schema for the domain parameter, and store the registrar, dates, status and nameservers with the time of the query.

The catalog reference quote for this method and path is $0.005.

The listed method and description establish the advertised contract. This explanation does not reproduce an HTTP 402 challenge or certify a paid response. Obtain the challenge for the exact request before authorizing payment, and compare resource, method, network, asset and amount together; a quote for one domain does not price a bulk lookup.

How this comparison is built

The comparison starts with services that are online and payment-ready, have a known price, a description of at least 80 characters and measured 30-day uptime of at least 90%. Task selection then reads the documented endpoints. Words such as WHOIS or RDAP in a service description can make a service a candidate, but a row needs a listed route that returns a registration record at a fixed reference quote.

Provider claims about record fields, sources, bundles and failure behavior were reviewed against the public service and endpoint descriptions captured on October 22, 2026. They remain provider claims. Monitoring supplies operating figures and reference prices; it does not check that a record matches the registry or that a name is really available. Buyer counts describe observed paying wallets for the service, with the coverage limits explained on its linked page.

The endpoint classification supplies the comparison quote, per-type prices and job candidates. Registration records can qualify a row. DNS, certificate, age and availability results remain adjacent types and cannot qualify a service or supply its price.

Questions

How to pay

Each service answers an unpaid call with HTTP 402 and its price; your agent signs a USDC payment on the listed network and retries. No API key, no account, no subscription. See what x402 is.