Domain check

Domain Check

You check domain availability using RDAP (the modern, structured replacement for whois), falling back to whois for TLDs that RDAP doesn't cover. Zero dependencies — Node's built-in fetch plus the system whois binary when present.

How availability is determined (read this first)

The CLI queries https://rdap.org/domain/<domain>, which redirects to the authoritative registry RDAP server:

• Redirected + HTTP 200 → registered (taken) — the response includes registration/expiry dates and registrar.
• Redirected + HTTP 404 → available (the registry says the name doesn't exist).
• Not redirected + HTTP 404 → RDAP has no server for that TLD (common for ccTLDs like .io, .co, .me, .sh). This is unknown, and the CLI then tries whois to resolve it.

This redirect check is why a naive "404 = available" approach is wrong for ccTLDs — .io domains return 404 from the RDAP front-end yet are very much registrable/registered. Always trust the CLI's classification, not a raw status code.

Prerequisites

1. Node 18+ (for global fetch): node --version.
2. whois (optional but recommended for ccTLD accuracy): command -v whois. Without it, ccTLDs that lack RDAP come back as unknown instead of available/taken.

No API key, no network config.

CLI

node <skill-directory>/scripts/cli.mjs <command> [args...]

Command	Description	Example
config	Show resolved config (merges domain-check.config.json with defaults)	config
check <domain...>	Check one or more exact domains	check slotly.io acme.com
scan <base> [--tlds=a,b]	Check a base name across configured TLDs	scan slotly
suggest <base>	Find available domains for a name (TLD sweep + get/use/try and hq/hub/… variants)	suggest slotly

All commands print JSON to stdout. Each result is { domain, status: "available"|"taken"|"unknown", source: "rdap"|"whois", registered?, expires?, registrar? }.

Execution Protocol

Step 0: Load configuration

node <skill-directory>/scripts/cli.mjs config

If _configFound is false you're on defaults — fine; mention it only if relevant. Config fields: rdapBase, timeoutMs, concurrency, tlds, suggestPrefixes, suggestSuffixes, suggestTlds, whoisFallback.

Step 1: Pick the command from intent

• "Is foo.com available?" / a specific domain or two → check
• "Check foo across TLDs" / "which TLDs are free for foo" → scan
• "Find me a domain for foo" / naming a new project → suggest

Step 2: Run and parse the JSON

Use Bash to run the command. The output is JSON — parse the results array and the convenience available list.

Step 3: Present results as a table (available first)

Show a compact table. Lead with available domains, then taken (with registration/expiry so the user can see when a squatted name might lapse), then any unknown. For example:

Domain	Status	Notes
slotly.sh	✅ available
slotly.com	❌ taken	reg. 2010, exp. 2026
slotly.io	❌ taken	via whois

For suggest, present the ranked available list as the headline answer (best/shortest/.com first), and note how many candidates were checked.

Limitations

• RDAP coverage: gTLDs (.com, .net, .org, .app, .dev, .ai, .xyz, …) are covered directly. Many ccTLDs (.io, .co, .me, .sh, .gg, .to) rely on the whois fallback; without whois they read as unknown.
• Premium / reserved / recently-expired names may be "available" in RDAP yet not purchasable or priced as premium. This tool answers "registered or not", not "buyable and at what price".
• Not a checkout: always confirm at a registrar before relying on a name.
• Be polite: concurrency defaults to 8; avoid hammering RDAP/whois with huge sweeps.