FQDN Lookup Skill

Overview

Fully Qualified Domain Name works by analyzing the IP address provided and getting the fully qualified domain name (FQDN). It uses DNS lookup to get the FQDN of the IP and returns the FQDN.

Live Test FQDN Lookup Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as FQDNLookupSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

{
  "name": "FQDNLookupSkill",
  "arguments": {
    "ip": "199.30.24.0"
  }
}

You do not name the tool yourself; the model picks it. Asking about 199.30.24.0 in the terms this skill covers is enough for it to reach for FQDNLookupSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

https://api.vervekit.com/v1/mcp

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

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{
  "status": "ok",
  "error": null,
  "data": {
    "ip": "199.30.24.0",
    "baseDomain": "msn.com",
    "fqdn": "msnbot-199-30-24-0.search.msn.com",
    "tld": "com",
    "subdomain": "msnbot-199-30-24-0.search",
    "domainLevels": 5,
    "detected": true
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

SIEM Log Enrichment

Security analysts resolve raw source IP addresses in firewall logs to identify hostnames, base domains, and top-level domains during triage.

Web Crawler Verification

To identify verified search engines, web servers check reverse DNS hostnames on incoming crawler IPs before granting rate limit exemptions.

Mail Server PTR Checks

Mail transfer agents verify incoming connection IP addresses against PTR domain levels and base domains to reject unconfigured relay servers.

Cloud Tenant Identification

Network engineers inspect resolved hostnames and subdomain structures from external server IPs to catalog multi-tenant infrastructure dependencies.

Other ways to use FQDN Lookup Skill

Set up FQDN Lookup Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Related

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