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/install domain-checker
Description
Check whether domain names are available for registration. Use when a user asks to verify domain availability, find unregistered domains, brainstorm project/...
README (SKILL.md)
Domain Checker
Check domain availability using whois + DNS cross-verification. Single source of truth for all domain availability queries.
Quick Start
Run the Python script (no system dependencies — no whois/dig CLI needed):
python3 scripts/check_domains.py example.com myproject.io brand.ai
Or pipe a list:
echo "foo.com bar.ai baz.io" | python3 scripts/check_domains.py
Legacy bash script (requires whois + dig CLI):
bash scripts/check_domains.sh example.com myproject.io brand.ai
Output Format
Each domain gets one of three verdicts:
| Symbol | Meaning | Confidence |
|---|---|---|
| ✅ AVAILABLE | whois says "not found" AND no DNS NS records | High |
| ❌ TAKEN | whois shows Creation Date OR DNS records exist | High |
| ⚠️ LIKELY TAKEN | Conflicting signals (whois unclear but DNS exists) | Medium |
| ❓ UNKNOWN | whois returned no data — verify manually | Low |
How It Works
Three independent signals are cross-verified:
- whois Creation Date — Most authoritative. If present, domain is taken.
- DNS NS records — Registered domains almost always have nameservers.
- DNS A records — Fallback signal for parked/active domains.
A domain is only marked AVAILABLE when whois explicitly says "not found" AND no DNS records exist. This eliminates false positives from unreliable whois web interfaces.
Important Notes
- Rate limiting: The script waits 1 second between queries to avoid whois server throttling. For large batches (>50), consider splitting into multiple runs.
- whois web interfaces are unreliable: Sites like whois.com often return stale/incorrect data. This script uses the
whoisCLI directly. - .ai TLD quirk: The .ai whois server sometimes returns sparse data. The script handles this by also checking DNS.
- Premium/aftermarket domains: A domain may be "available" in whois but listed at a premium price on registrars. The script cannot detect this — check the registrar for actual purchase price.
- Python script: No system dependencies — uses stdlib
socketfor whois (port 43) and DNS resolution. - Bash script (legacy): Requires
whoisanddigCLI tools (pre-installed on most Linux/macOS systems).
Batch Domain Brainstorming
When helping users brainstorm project names with domain checks, use this workflow:
- Generate 15-30 candidate names based on user criteria
- Run all candidates through the script in one batch
- Present only the AVAILABLE results with analysis
- Iterate on available candidates if needed
Example:
python3 scripts/check_domains.py myapp.com myapp.ai myapp.io coolname.com coolname.ai
Usage Guidance
This skill appears to do what it says: run the included Python or bash script to check whois + DNS for domains. Before installing/running: ensure your environment allows outbound WHOIS (TCP port 43) and DNS lookups, avoid running very large batches without respecting rate limits (script sleeps 1s), and understand results can be imperfect (premium/marketplace listings or registrar edge cases are not detected). Note the small doc/code mismatch: the Python comment mentions an HTTP whois fallback but the code uses direct port 43 whois only. If you need registrar pricing or guaranteed up-to-date results, use official registrar APIs instead.
Capability Analysis
Type: OpenClaw Skill
Name: domain-checker
Version: 1.1.0
The skill bundle provides legitimate tools for checking domain name availability using WHOIS and DNS lookups. The Python script (scripts/check_domains.py) and Bash script (scripts/check_domains.sh) use standard network protocols and system utilities to verify registration status, with no evidence of data exfiltration, command injection, or malicious intent. The instructions in SKILL.md are consistent with the tool's purpose and do not contain any prompt injection attempts.
Capability Tags
Capability Assessment
Purpose & Capability
Name/description match the included files: both Python and bash scripts perform whois queries and DNS checks for TLDs listed in the SKILL.md. Network access to whois servers and DNS resolution is necessary and expected.
Instruction Scope
SKILL.md's runtime instructions stay within the stated purpose (run the included scripts, pipe domains, respect rate limits). Minor inconsistency: SKILL.md and the Python docstring mention an HTTP whois API fallback via urllib, but the Python code implements direct whois over TCP port 43 and DNS lookups only (no urllib usage). Otherwise the scripts only perform network queries relevant to domain checking and do not read unrelated files or env vars.
Install Mechanism
No install spec (instruction-only), no downloads or package installs. The code files are provided in the skill bundle; nothing is written to disk by an installer step beyond the natural act of running the included scripts.
Credentials
The skill requests no environment variables, credentials, or config paths. It requires outbound network access (TCP port 43 to whois servers and standard DNS resolution) which is appropriate and proportional to domain availability checks.
Persistence & Privilege
always is false and the skill does not request persistent or elevated platform privileges, nor does it modify other skills or system-wide settings.
How to Use
- Make sure OpenClaw is installed (local or Docker)
- Run the install command in chat:
/install domain-checker - After installation, invoke the skill by name or use
/domain-checker - Provide required inputs per the skill's parameter spec and get structured output
Version History
v1.1.0
Add pure Python domain checker (no whois/dig CLI needed). Uses stdlib socket for whois (port 43) + DNS resolution. Legacy bash script preserved as fallback.
v1.0.0
Check domain availability using `whois` + DNS cross-verification. Single source of truth for all domain availability queries.
Metadata
Frequently Asked Questions
What is Domain Checker?
Check whether domain names are available for registration. Use when a user asks to verify domain availability, find unregistered domains, brainstorm project/... It is an AI Agent Skill for Claude Code / OpenClaw, with 396 downloads so far.
How do I install Domain Checker?
Run "/install domain-checker" in the OpenClaw or Claude Code chat to install it in one step — no extra setup required.
Is Domain Checker free?
Yes, Domain Checker is completely free, licensed under MIT-0. You can download, install and use it at no cost.
Which platforms does Domain Checker support?
Domain Checker is cross-platform and runs anywhere OpenClaw / Claude Code is available (cross-platform).
Who created Domain Checker?
It is built and maintained by Yulong (@blueyi); the current version is v1.1.0.
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