---
title: "Lookup any AS Number and receive it's details"
method: GET
path: "/lookup/asn"
---

# Lookup any AS Number and receive it's details

`GET /lookup/asn`

This API method allows you to look up any given Autonomous System Number (ASN) and retrieve comprehensive data associated with it.

The information returned includes the ASN name, organization name, country, associated domain, contact email, phone number, total IPs, and a detailed list of all related routes (both IPv4 and IPv6). This functionality is essential for network analysis, troubleshooting, and understanding the infrastructure behind IP addresses.

## Query parameters

- `asn` string
- `isList` string
- `format` string
- `callback` string
- `mode` string

## Response `200`

OK

## Other responses

- `400` — Bad Request
- `500` — Internal Server Error

---

[API](https://skmtc.dev/greip/apis/greip-api.md) · [All operations](https://skmtc.dev/greip/apis/greip-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/greip/greip-api/revisions/710e218152d5/schema)