domain-checker

domain-checker is an agent for Claude Code from luongnv89/skills. It costs 22 tokens per session (1,186 once invoked), scanned A, original, MIT.

A domain-name checking agent for .com, .io, .app, .co, and requested regional endings. A domain name is the web address people use to reach a site.

In plain words
What is it for?
Use it to check a proposed name across common and regional domain endings and receive a status for each one.
Why use it?
It helps distinguish names that appear available from names that are already registered, parked, or actively used. The checks combine registry-status searches with searches for live websites.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

Good fit Use it to check a proposed name across common and regional domain endings and receive a status for each one.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/luongnv89/skills/domain-checker
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/luongnv89/skills

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for domain-checker

README.md
[![agentmods](https://agentmods.dev/badge/agents/luongnv89/skills/domain-checker.svg)](https://agentmods.dev/agents/luongnv89/skills/domain-checker)
Your own site
<a href="https://agentmods.dev/agents/luongnv89/skills/domain-checker"><img src="https://agentmods.dev/badge/agents/luongnv89/skills/domain-checker.svg" alt="Measured on agentmods" height="20"></a>
Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,186 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00022 $0.01186
Opus 5 $0.00011 $0.00593
Sonnet 5 $0.00004 $0.00237
Haiku 4.5 $0.00002 $0.00119

Measured 8d ago against content hash 9d1e7f8bc91a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

domain-checker scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/brand-name-checker/agents/domain-checker.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Domain Checker Agent

Check domain availability across .com, .io, .app, .co and regional TLDs, returning registration status and active site info.

Input

{
  "name": "myproductname",
  "regional_tlds": ["eu", "fr"]
}

Process

Check each TLD independently:

Primary TLDs

  1. .com - Highest priority, most sought-after
  2. .io - Popular for tech startups
  3. .app - Google registry, modern and trustworthy
  4. .co - Alternative to .com, increasingly popular

Regional TLDs

  • .eu - European Union
  • .fr - France (if relevant)
  • Other regional codes as provided in input

For each TLD, search:

  • Query 1: "[NAME].[TLD]" domain registry status
  • Query 2: site:[NAME].[TLD] to check for active site
  • Query 3: Domain registrar availability (GoDaddy, Namecheap, etc.)

Status Determination

  • Available: No active site, domain not registered
  • Parked: Domain exists but no active site (parking page, "for sale")
  • Active: Domain registered and in use

Output

Return JSON with this structure:

{
  "name": "myproductname",
  "timestamp": "2026-03-24T10:30:00Z",
  "domain_status": {
    "com": {
      "status": "available|parked|active|error",
      "tld": ".com",
      "full_domain": "myproductname.com",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    },
    "io": {
      "status": "available|parked|active|error",
      "tld": ".io",
      "full_domain": "myproductname.io",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    },
    "app": {
      "status": "available|parked|active|error",
      "tld": ".app",
      "full_domain": "myproductname.app",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    },
    "co": {
      "status": "available|parked|active|error",
      "tld": ".co",
      "full_domain": "myproductname.co",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    },
    "eu": {
      "status": "available|parked|active|error",
      "tld": ".eu",
      "full_domain": "myproductname.eu",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    },
    "fr": {
      "status": "available|parked|active|error",
      "tld": ".fr",
      "full_domain": "myproductname.fr",
      "site_found": false,
      "site_description": null,
      "site_industry": null,
      "registrar": "registrar name or null",
      "expiry": "2026-04-15 or null",
      "confidence": "high|medium|low"
    }
  },
  "summary": {
    "com_status": "available|parked|active",
    "com_critical": true,
    "all_primary_available": false,
    "primary_available": ["io", "app", "co"],
    "primary_taken": ["com"],
    "active_in_same_industry": false
  },
  "notes": "myproductname.com is active but parked. io, app, co available. Consider acquiring at least .io if .com unavailable."
}

Read the full file on GitHub · 152 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 152 lines · 22 tokens per session scan A 9d1e7f8bc91a

Subscribe to this mod's changes

domain-checker is an agent published in the GitHub repository luongnv89/skills (123 stars, last pushed 3d ago), licensed MIT. It adds 22 tokens to every session and 1,186 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.