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domain-checker

Check domain registration in batches using public RDAP APIs, without keys or login.

Skill by davidondrej

IndexedMIT★ 4,167
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Install

Works with Claude Code, Claude apps, Codex, Cursor, Gemini CLI, GitHub Copilot, VS Code, OpenCode, Goose, Windsurf. Read the repository before you give any tool access to your data.

npx agentmarket install skill/davidondrej-domain-checker

Asks which of your tools to add it to (Claude Code, Codex, Cursor, VS Code, Windsurf, Gemini CLI, Claude Desktop) and shows the change first. See https://agentmart.dev/cli.

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About

Check domain registration in batches using public RDAP APIs, without keys or login. Use only when the user explicitly invokes /domain-checker.

Use cases: research, api-integration

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Permissions

What this skill can do and what it asks for, from its SKILL.md. Checked Oct 25, 2026.

Tools
No tools found
Secrets
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Install scripts
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Runs as
Python package

Network hosts it talks to 1

  • codeload.github.com · found in install command

Files it touches

  • ~/.claude/skills/domain-checker

What's inside

Skill name
domain-checker
Description
Check domain registration in batches using public RDAP APIs, without keys or login. Use only when the user explicitly invokes /domain-checker.
License
MIT
Instructions
31 lines in SKILL.md · view on GitHub

Before installing

  • Ships executable scripts

Files (3)

  • SKILL.md
  • openai.yaml · agents/
  • check_domains.py · scripts/

SKILL.md (first lines)

# 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.

```sh
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](https://data.iana.org/rdap/dns.json), [RDAP HTTP semantics](https://www.rfc-editor.org/rfc/rfc7480.html), [RDAP.org status and rate-limit distinctions](https://about.rdap.org/).

From davidondrej/skills, MIT.

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Last commit (this folder)
Sep 26, 2026 (1 month ago)

From GitHub (fetched Oct 24, 2026).

Details

License
MIT
First seen
Oct 24, 2026
Last checked
Oct 24, 2026

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Cite this page

domain-checker skill. Agent Mart. https://agentmart.dev/skills/davidondrej-domain-checker (last updated 2026-10-24)