node-geoip-country

Look up the country associated with an IPv4 address.

Usage

Add the client library to your Node.js module:

npm i node-geoip-country

The client can be used like so:

import { NodeGeoipCountryClient } from "node-geoip-country";

const client = new NodeGeoipCountryClient(data);
const countryIso2Code = client.lookUp("8.8.8.8");

Data

The data is built and stored separately from the library, to avoid tying library and data versions and allow different datasets.

This repo will generate data based on herrbischoff/country-ip-blocks and upload it to https://wilsonl.in/node-geoip-country/data.json every hour. To use it, simply fetch and parse as JSON, then provide to the client constructor.

To build or use custom data, the structure should match the IpPrefixTrieNode type:

export type IpPrefixTrieNode = [IpPrefixTrieNode?, IpPrefixTrieNode?, string?];

It's a bit string trie data structure, represented as a JSON-compact array, where the first element represents any 0 child, the second represents any 1 child, and the third represents the node's value (i.e. country) if available.

During lookup, an IPv4 address is converted to a 32-digit bit string and the longest match is used as the result.