ASN Lookup
Look up the network operator, country, and address block behind any IP address or ASN number. Given an internet address (IP) or a network identification number (ASN), this tool returns who operates that piece of the internet: the network number, the owner's name, the country it's registered in, the regional registry that manages it, and the exact address range it belongs to. Pay-per-call at $0.01 USDC over x402 on Base or Solana — no account, no API key. OpenAPI 3.1.0; 1 operation(s): POST /lookup.
This API exposes 1 operation across 1 path, and defines 4 schemas. It is described by OpenAPI 3.1.0, at version 1.0.0.
Requests are made against a single base URL, https://asn-lookup.underscoredone.com.
Metadata
The identity and technical contract details declared by the specification.
Authentication & Security 1
ASN Lookup declares
1 security scheme
for authenticating requests.
An API key is passed in the header as SIGN-IN-WITH-X (siwx).
siwx— CAIP-122 wallet signature for repeat access after payment
Paths & Operations 1
Across 1 path, the API surfaces 1 operation — 1 POST. Each is listed below with its method, path, parameters, and response codes.
Schemas 4
The contract defines 4 schemas that model the data the API accepts and returns. The most detailed are Response (8 properties), ValidationError (5 properties), Request (1 property), HTTPValidationError (1 property). Each schema is shown below with its type and property counts.
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
This is an independent, third-party profile of ASN Lookup, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
info@apievangelist.com
·
Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and
you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.