Domain Search

Brainstorm brandable names and check which domains are actually available to register.

How availability is checked: RDAP (not WHOIS, not a paid API)

Availability is determined with RDAP — the official IETF successor to WHOIS (RFC 9082/9083). Query https://rdap.org/domain/<fqdn>, which routes to the responsible registry and returns:

• HTTP 404 → AVAILABLE (no registration record exists)
• HTTP 200 → TAKEN (a registration record exists)
• anything else → UNKNOWN (TLD has no RDAP server, rate-limited, or network issue)

This is authoritative and free. It is more reliable than scraping Instant Domain Search / GoDaddy, whose public endpoints change and rate-limit. RDAP tells you registered or not; it does not price premium/reserved names — confirm the final price at a registrar.

Caveats (state these when relevant)

• Not all TLDs publish RDAP. .io historically had no RDAP, and some ccTLDs still don't.

UNKNOWN means "couldn't determine" — never report it as available.

• .com, .ai, .net, .org, .app, .dev, .co work well via RDAP.
• An RDAP-available name can still be a premium listing (high price). Verify at checkout.

The script

scripts/check-domains.sh — batch checker. Always pass it as an explicit list (zsh does not word-split unquoted variables, so loop over arrays or pass args directly).

# Names × TLDs (cartesian):
bash scripts/check-domains.sh --tlds com,ai,app myname otherword

# Explicit FQDNs:
bash scripts/check-domains.sh acme.com acme.ai foo.io

# Machine-readable (for further processing):
bash scripts/check-domains.sh --json --tlds com,ai myname

Output uses ✅ AVAILABLE / ❌ taken / ❓ unknown.

Workflow

1. Understand the product before brainstorming. Check the repo, README, and (if present)

the user's memory/notes so names fit the actual positioning, audience, and tone.

1. Brainstorm in styles, not at random — mix: real words, invented/portmanteau, foreign

words, compounds, and verb+suffix (-ly, -ify, -ish). Short single words are almost always taken on .com; compounds and coined words are where .com wins are found.

1. Batch-check with the script across the TLDs the user cares about (default .com,.ai).
2. Present results grouped by availability, leading with names available on the user's

preferred TLD. For each, give a one-line rationale (what it evokes) so the choice is informed.

1. Remind that RDAP-available ≠ final price; premium names cost more — verify at a registrar

(Cloudflare Registrar is at-cost and a good default if the user already uses Cloudflare).

Tips

• Default to checking .com and .ai; add .app/.io/.dev for developer-facing tools.
• If the user already owns domains (e.g. registered at Cloudflare), check whether one fits

before suggesting new purchases — reusing an owned domain is free.

• Avoid names colliding with direct competitors or trademarks; flag near-misses you notice.