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nomlen api· REST + MCP · free

Domain data API for developers and AI agents

Availability, WHOIS, DNS, true-cost TLD pricing and valuations — the live data behind Nomlen's tools, as a REST API and an MCP server your AI agent can call directly.

Get your free API key

200 requests a day, no card, up to 3 active keys per email. The key is shown once — we store only its hash.

REST endpoints

Base URL https://nomlen.com · send your key as Authorization: Bearer nml_… or X-API-Key. Responses are JSON: { success, data } or { success: false, error }.

GET/api/v1/check?domain=example.com

Domain availability

Live registry availability for one domain — available, taken, premium or unknown. Verisign for .com/.net, registry WHOIS for .io/.ai/.me/.tv.

curl "https://nomlen.com/api/v1/check?domain=vertex.io" \
  -H "Authorization: Bearer nml_YOUR_KEY"
GET/api/v1/whois?domain=example.com

WHOIS lookup

Registrar, creation and expiry dates, nameservers and the raw WHOIS record for any domain.

curl "https://nomlen.com/api/v1/whois?domain=vertex.com" \
  -H "Authorization: Bearer nml_YOUR_KEY"
GET/api/v1/dns?domain=example.com

DNS records

Live A, AAAA, CNAME, MX, TXT, NS, SOA and CAA records in one call.

curl "https://nomlen.com/api/v1/dns?domain=nomlen.com" \
  -H "Authorization: Bearer nml_YOUR_KEY"
GET/api/v1/pricing?tld=ai

TLD pricing

Cheapest real registration and renewal prices for a TLD, the 5-year true cost, and a renewal-trap flag when renewal costs far more than registration.

curl "https://nomlen.com/api/v1/pricing?tld=ai" \
  -H "Authorization: Bearer nml_YOUR_KEY"
GET/api/v1/valuation?domain=example.com

Domain valuation

A heuristic value estimate for a registered domain with the signals behind it — the same engine as the Domain Valuation tool.

curl "https://nomlen.com/api/v1/valuation?domain=vertex.com" \
  -H "Authorization: Bearer nml_YOUR_KEY"

MCP server — for AI agents

Nomlen speaks the Model Context Protocol. Point any MCP client at https://nomlen.com/api/mcp with your API key and the agent gets five tools: check_domain_availability, whois_lookup, dns_lookup, tld_pricing, domain_valuation.

Client config (Claude Desktop, Cursor, and other MCP clients)
{
  "mcpServers": {
    "nomlen": {
      "url": "https://nomlen.com/api/mcp",
      "headers": {
        "Authorization": "Bearer nml_YOUR_KEY"
      }
    }
  }
}

Listing tools needs no key; calling them does — same key, same 200/day limit as the REST API.

Limits & fair use

  • 200 requests per day per key (REST and MCP share the limit), resetting at midnight UTC.
  • Up to 3 active keys per email. Keys never expire; revoke any time from this page.
  • Data is live registry and pricing data — availability can change between your call and checkout, so confirm at the registrar before promising a name to a client.
  • Don't resell raw bulk access or hammer the endpoints; abusive keys get revoked.
Keep exploring

Related free tools

Bulk Domain Search

Check availability for hundreds of domains at once.

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Bulk WHOIS Check

WHOIS data for many domains in one pass.

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DNS Checker

Look up A, MX, TXT, NS and more DNS records instantly.

Try it
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