ASN Lookup Skill

Overview

Pass an ASN with or without the leading prefix. The endpoint queries daily-updated registry data to return the registered organization name and numeric identifier. Paid plans include the two-letter country code, registry handle, and the total count of announced IPv4 and IPv6 address ranges.

Live Test ASN Lookup Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as ASNLookupSkill. 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.

Tool call

{
  "name": "ASNLookupSkill",
  "arguments": {
    "asn": "AS15169"
  }
}

You do not name the tool yourself; the model picks it. Asking about AS15169 in the terms this skill covers is enough for it to reach for ASNLookupSkill 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"
    }
  }
}

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.

Argument	Type	Description
`asn`Required	string	The ASN you want to get information about

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.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "asn": "AS15169",
    "simple": "15169",
    "handle": "GOOGLE",
    "description": "Google LLC",
    "country": "US",
    "ipv4RangeCount": 152,
    "ipv6RangeCount": 33,
    "ipv4AddressCount": 1314816
  }
}

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.

Field	Type	Example	Description
`asn`	string	`AS15169`	Full ASN notation (e.g., AS15169 for Google)
`simple`	string	`15169`	Numeric ASN without AS prefix (e.g., 15169)
`handle`Premium	string	`GOOGLE`	Registry handle or short identifier for the AS
`description`	string	`Google LLC`	Organization name or description associated with ASN
`country`Premium	string	`US`	Two-letter country code where the ASN is registered
`ipv4RangeCount`Premium	number	`152`	Number of IPv4 address ranges this AS announces
`ipv6RangeCount`Premium	number	`33`	Number of IPv6 address ranges this AS announces
`ipv4AddressCount`Premium	number	`1314816`	Total IPv4 addresses across those ranges

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.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 4 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Incident Investigation: When investigating an alert, security teams resolve suspicious IP ownership to determine which hosting provider or telco operates the network.
Bot Traffic Filtering: Flag incoming requests originating from cloud hosting providers rather than consumer internet service providers to block automated scraping.
Signup Fraud Prevention: To stop payment fraud, risk engines compare the cardholder's billing country against the ASN registration country associated with the transaction.
Network Peer Analysis: Network engineers track upstream transit providers by looking up ASNs captured in NetFlow and BGP routing table dumps.

Other ways to use ASN Lookup Skill

Set up ASN 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.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →