davidondrejInstall Domain Checker
Pick your agent. Every command is ready to paste.
npx skills add davidondrej/skills --skill domain-checkerThe open skills CLI detects your agents (Claude Code, Cursor, Codex and 70+ more) and installs to the right folder. Add -g to install globally.
01
Install it
Run the command above, or upload the folder in Claude.
02
Ask naturally
Describe the task. Your agent loads domain-checker when the request matches its description.
03
Name it if needed
If it does not trigger, say “use the domain-checker skill”. In Codex, type $domain-checker.
Domain checker
Run the bundled Python 3 checker without packages, credentials or a browser. Resolve scripts/check_domains.py relative to this SKILL.md, regardless of the working directory.
python3 <skill-dir>/scripts/check_domains.py example.com example.dev example.ai --json
Use complete domains, not bare brand names or URLs; expand each name/TLD combination. Only domains directly under a TLD are supported (e.g. .com, .dev, .ai, .cloud), not multi-label suffixes such as .co.uk.
The script discovers endpoints through IANA and queries public registries, not registrar shopping carts. Use small batches; concurrency is capped at 4 requests.
Read the results
JSON output is an array of {domain, status, detail} objects. Without --json, output is a short list and elapsed time.
REGISTERED: matching registration record found.NOT_FOUND: registry reports no record. Not confirmed available: reservations, registration rules or premium pricing may prevent purchase.UNAVAILABLE: registry explicitly reports a reservation or registration restriction.UNKNOWN: unsupported registry, malformed response, timeout or HTTP error. Never treat as available.INVALID: malformed name or input outside the helper’s scope.
Report briefly as a live snapshot, preserving exact domains and statuses. Explain UNKNOWN reasons. On rate limits, wait before retrying; do not increase concurrency. Bootstrap failure exits nonzero: no checks completed.
Read registry error bodies: a 404 may report a reservation, while Verisign may return an empty RDAP 404. The helper handles both but detects only some reservation wording. Neither DNS absence nor RDAP redirect-service errors prove availability.
Use a registrar for final purchase availability or premium quotes. Registration checks do not establish whether another company uses the name or provide trademark clearance.
Sources: IANA registry discovery, RDAP HTTP semantics, RDAP.org status and rate-limit distinctions.
Tips for Domain Checker
- • Start a fresh session after installing so your agent picks up the new skill.
- • This skill ships scripts. Read them before the first run, and run it in a project without secrets first.
- • It is part of a pack with 30 skills. Install only the ones you need with --skill to keep triggers precise.
- • If two skills overlap, mention the one you want by name.
Questions about Domain Checker
What does the Domain Checker skill do?
Check domain registration in batches using public RDAP APIs, without keys or login. Use only when the user explicitly invokes /domain-checker.
How do I install Domain Checker?
Run "npx skills add davidondrej/skills --skill domain-checker" in your project. The skills CLI installs it for Claude Code, Cursor, Codex and 70+ other agents. In Claude on the web, upload the skill folder as a ZIP under Customize > Skills.
Does Domain Checker work in Cursor and Codex?
Yes. Domain Checker uses the open SKILL.md format, so it works in Claude Code, Claude, Cursor, OpenAI Codex, Gemini CLI, GitHub Copilot and other agents that support agent skills.
Is Domain Checker free?
Domain Checker is open source on GitHub under the MIT license. It is free to install; check the license before commercial use.
Who made Domain Checker?
Domain Checker is published by davidondrej in the davidondrej/skills repository, together with 29 other skills.
