How do I install the Domain Check skill?

Run npx skillmds@latest add simp-lee/domain-check in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Domain Check safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Domain Check?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Domain Check free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Domain Check?

simp-lee (@simp-lee) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Domain Check by simp-lee — Agent Skill

Name: Domain Check
Author: simp-lee

Domain Check

Batch domain availability checker via whois.com with Playwright browser automation. Handles anti-bot/CAPTCHA challenges by bringing browser to foreground for manual verification. Supports any TLD. Use when (1) checking if domains are available for registration, (2) batch-checking multiple domain candidates, (3) verifying domain availability before purchase, or (4) exporting domain check results to JSON.

simp-lee 7579c98 6 files · 18.0 KB Updated Sep 17, 2026

File contents

Domain Availability Check

Batch-check domain availability via whois.com with anti-bot/CAPTCHA assist.

Quick Start

# Setup (first time)
cd $SKILL_DIR && npm run setup

# Check domains from command line
node run.js scripts/domain-check.js --domains "example.ai,myapp.io" --nslookup

# Check domains from file
node run.js scripts/domain-check.js --file domains.txt --out results.json --nslookup

File format: one domain per line, # for comments. See examples/domains.txt.

Options

Option	Description	Default
`--domains`	Comma-separated domain list	-
`--file`	Path to domain list file	-
`--out`	Output JSON file path	stdout
`--nslookup`	Corroborate with DNS lookup	`false`
`--user-data-dir`	Persistent browser profile (reduces CAPTCHA)	-
`--challenge-wait`	Max CAPTCHA wait time (ms)	`120000`
`--delay`	Delay between checks (ms)	`900`

Behavior

Opens visible browser (headless=false) for CAPTCHA handling.
On Security Check / CAPTCHA: brings browser to front, waits for manual completion.
Classification rules:
- Looks like this domain has not been registered yet -> available
- Domain Information / Registrar Information -> registered
- WHOIS patterns like No match for, Domain not found -> available
--nslookup: NXDOMAIN suggests unregistered DNS (corroboration only).

Output

JSON array with domain, status (available|registered|unknown|error), nslookup.

Tips

Use --user-data-dir ./profile to reduce repeated CAPTCHA challenges.
Run sequentially to minimize anti-bot triggers.

---name: domain-checkdescription: Batch domain availability checker via whois.com with Playwright browser automation. Handles anti-bot/CAPTCHA challenges by bringing browser to foreground for manual verification. Supports any TLD. Use when (1) checking if domains are available for registration, (2) batch-checking multiple domain candidates, (3) verifying domain availability before purchase, or (4) exporting domain check results to JSON.---# Domain Availability CheckBatch-check domain availability via whois.com with anti-bot/CAPTCHA assist.## Quick Start```powershell# Setup (first time)cd $SKILL_DIR && npm run setup# Check domains from command linenode run.js scripts/domain-check.js --domains "example.ai,myapp.io" --nslookup# Check domains from filenode run.js scripts/domain-check.js --file domains.txt --out results.json --nslookup```File format: one domain per line, `#` for comments. See `examples/domains.txt`.## Options| Option | Description | Default ||--------|-------------|---------|| `--domains` | Comma-separated domain list | - || `--file` | Path to domain list file | - || `--out` | Output JSON file path | stdout || `--nslookup` | Corroborate with DNS lookup | `false` || `--user-data-dir` | Persistent browser profile (reduces CAPTCHA) | - || `--challenge-wait` | Max CAPTCHA wait time (ms) | `120000` || `--delay` | Delay between checks (ms) | `900` |## Behavior- Opens visible browser (`headless=false`) for CAPTCHA handling.- On Security Check / CAPTCHA: brings browser to front, waits for manual completion.- Classification rules: - `Looks like this domain has not been registered yet` -> **available** - `Domain Information` / `Registrar Information` -> **registered** - WHOIS patterns like `No match for`, `Domain not found` -> **available**- `--nslookup`: NXDOMAIN suggests unregistered DNS (corroboration only).## OutputJSON array with `domain`, `status` (`available`|`registered`|`unknown`|`error`), `nslookup`.## Tips- Use `--user-data-dir ./profile` to reduce repeated CAPTCHA challenges.- Run sequentially to minimize anti-bot triggers.

Frequently asked questions