🔍

WHOIS

whois.4bots.ai

Domain intelligence in one call. WHOIS, DNS, SSL certificates, and tech stack detection — normalized into clean JSON so your agent doesn't have to parse registrar HTML.

Live Free — 10/day 4 Data Sources x402 Native MCP Compatible

One domain. One request. Full picture.

Your agent needs to know who owns a domain, what DNS it uses, whether the SSL cert is valid, and what tech stack it runs. Normally that's four different tools and four parsing jobs. WHOIS does it all in one call and returns structured JSON.

🪪 WHOIS lookup

Registrant info, registrar, creation/expiry dates, name servers. Uses RDAP first (modern, structured), falls back to WHOIS CLI for edge cases.

🌐 DNS resolution

A, AAAA, MX, NS, TXT records via dig. Know where the domain points before your agent sends a request there.

🔒 SSL certificate

Issuer, expiry, subject alternative names. Paid tier adds full cert chain details. Never get caught by an expired cert again.

🛠️ Tech fingerprinting

Server headers, framework detection, CDN identification. Paid tier adds deeper header analysis. Know what you're talking to before you talk to it.

Public data. Clean delivery.

All data comes from public sources. We aggregate, normalize, and cache it — so your agent gets consistent JSON instead of scraping registrar websites.

Primary

RDAP

Registration Data Access Protocol. The modern replacement for WHOIS. Structured JSON from IANA-registered RDAP servers. Covers 90%+ of TLDs.

Fallback

WHOIS CLI

Legacy WHOIS protocol via whois command. Used when RDAP doesn't have coverage for a TLD. Raw output parsed into structured fields.

DNS

dig

Standard DNS resolution via dig. A, AAAA, MX, NS, TXT records. Resolves from our VPS in Nuremberg for consistent results.

SSL

OpenSSL

SSL certificate inspection via openssl s_client. Issuer, expiry, SANs, protocol version. Paid tier adds full chain verification.

One endpoint. Full recon.

GET /v1/free/whois/lookup?domain=:domain

Get full domain intelligence for any domain.

curl "https://whois.4bots.ai/v1/free/whois/lookup?domain=example.com"

Example response:

{
  "domain": "example.com",
  "whois": {
    "registrar": "RESERVED-Internet Assigned Numbers Authority",
    "created": "1995-08-14T04:00:00Z",
    "expires": null,
    "name_servers": ["a.iana-servers.net", "b.iana-servers.net"],
    "status": ["clientDeleteProhibited", "clientTransferProhibited"]
  },
  "dns": {
    "a": ["93.184.216.34"],
    "aaaa": ["2606:2800:220:1:248:1893:25c8:1946"],
    "mx": [],
    "ns": ["a.iana-servers.net", "b.iana-servers.net"],
    "txt": []
  },
  "ssl": {
    "issuer": "DigiCert Inc",
    "expires": "2024-12-31T23:59:59Z",
    "san": ["example.com", "www.example.com"],
    "valid": true
  },
  "free_remaining": 7
}

GET /v1/free/whois/lookup?domain=:domain

DNS-only lookup. Faster when you don't need WHOIS or SSL.

curl "https://whois.4bots.ai/v1/free/whois/lookup?domain=example.com"

GET /health

Health check. Always free, always returns 200.

curl "https://whois.4bots.ai/health"

Free to try. Pennies to scale.

10 free lookups per day covers development and light agent workloads. Paid tier unlocks SSL details, tech fingerprinting, and unlimited volume.

Free
$0 / month
No wallet required
  • 10 lookups / day
  • WHOIS (RDAP + CLI fallback)
  • DNS records (A, AAAA, MX, NS, TXT)
  • Basic SSL (issuer, expiry, valid)
  • JSON output
Paid
$0.002 / lookup
via x402 USDC on Base
  • Unlimited lookups
  • Everything in Free
  • Full SSL cert chain details
  • Tech stack fingerprinting
  • Header analysis (server, framework, CDN)

Look up a domain now.

No signup. No API key. Just send a request.

How x402 works