IP address classifier API: private, public, loopback or link-local
Classify an IPv4 or IPv6 address without any lookup: version, whether it is private, loopback, link-local, carrier-grade NAT or public, and its integer and reverse-DNS forms (IPv4). Use to triage IPs in logs or allowlists.
When to use it
- Triage IPs in logs or allowlists
- Tell private, loopback, link-local, carrier-grade NAT and public addresses apart
- Get the integer and reverse-DNS forms of an IPv4 address
Inputs
| Name | Type | Description |
|---|---|---|
ip (required) | string | The IP address |
Request
Over HTTP, with a card key from /credits:
curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/ip/info?ip=10.1.2.3"Or one of your 25 free calls, no key:
curl "https://tools.funwords.eu/ip/info?ip=10.1.2.3&trial=1"Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum or Solana over x402; Base or Tempo over MPP) and retries.
Example result
{
"ip": "10.1.2.3",
"version": 4,
"private": true,
"loopback": false,
"linkLocal": false,
"public": false,
"integer": 167838211,
"reverseDns": "3.2.1.10.in-addr.arpa"
}From an AI agent (MCP)
Add the MCP server to Claude, Cursor or any MCP client. This tool is ip_info, and the first 25 successful calls are free:
https://tools.funwords.eu/mcpQuestions
Does it look up geolocation or ownership?
No. It classifies the IPv4 or IPv6 address without any lookup.
How do I pay?
Each successful call costs $0.01; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.