domain-check

Reconcile conflicting domain availability verdicts across RDAP, DNS, brokers, and registrars.

14|1|Updated Jun 14, 2026
One-click install
npx skills add https://github.com/allemaar/open-skills --skill domain-check-allemaar
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: domain-check
Source: https://github.com/allemaar/open-skills/tree/main/skills/domain-check
Command: npx skills add https://github.com/allemaar/open-skills --skill domain-check-allemaar

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Registrar availability tools frequently report registered, broker-parked domains as available, producing false positives that waste time and mislead purchase decisions. This Skill defines a source-precedence policy that reconciles RDAP, DNS, broker nameservers, and registrar APIs into one auditable verdict. ## Core Features & Use Cases - Authoritative precedence order: RDAP (resolved via the IANA bootstrap file) outranks DNS, broker nameserver matches override any registrar "available" claim, and registrar APIs are used for price context only. - Aftermarket detection: Matches nameserver registrable domains against known broker operators (afternic, sedo, dan.com, namefind, and others) to flag registered-and-brokered domains. - Bulk candidate sweeps: Runs serial checks with backoff and rate-limit awareness for RDAP and WHOIS, labeling WHOIS-derived verdicts as lower-confidence. - Use Case: You have a shortlist of 20 candidate brand domains. Run a bulk sweep to get a verdict per domain — available, registered, registered-and-brokered, or unknown — each with the agreeing sources and residual uncertainty stated. ## Quick Start Ask the agent to check whether a list of candidate domain names is actually available, reconciling RDAP, DNS, and broker nameservers before trusting any registrar result.

Frequently Asked Questions about domain-check

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I check if a domain name is really available?▼

Query the registry's RDAP endpoint resolved through the IANA bootstrap file — HTTP 404 means unregistered, 200 means registered. Corroborate with DNS NS lookups on two resolvers, and never trust a registrar's binary available answer alone.

Why does a registrar say a domain is available when it is registered?▼

Registrar availability endpoints often use fast, non-definitive checks that miss broker-parked domains. Domains parked on aftermarket nameservers like afternic.com or namefind.com can be reported as available even though RDAP confirms they are registered.

How do I detect brokered or aftermarket domains from nameservers?▼

Reduce each nameserver hostname to its registrable domain and compare it against known broker operators such as afternic, sedo, dan.com, bodis, namefind, and domainmarket. Match the registrable domain, not a raw substring, to avoid false positives like sedona.com.

Does an RDAP 404 mean I can register the domain?▼

No. An RDAP 404 means probably registrable, but reserved strings, sunrise or landrush restrictions, and registry-premium pricing can still block registration. Registrar pricing and registry policy remain unknown unless separately checked.

What are the rate limits for bulk domain availability checks?▼

rdap.org caps at 10 requests per 10 seconds, and WHOIS can IP-ban at roughly more than one query per second per address. For bulk sweeps, query registry-direct RDAP endpoints serially with backoff and never fan out in parallel.

When is WHOIS needed instead of RDAP for domain checks?▼

Roughly 189 country-code TLDs have no RDAP service, so WHOIS is the only fallback there. WHOIS output is free-text and parse-fragile, so any WHOIS-derived verdict should be labeled lower-confidence in the report.