Detect VPN, Proxy & Tor in .NET

No dedicated call needed — the properties ride along with a normal LookupAsync.

var client = new IpApiClient(Environment.GetEnvironmentVariable("IP_API_IO_KEY")!);

var info = await client.LookupAsync("185.220.101.1");
var f = info.SuspiciousFactors;

Console.WriteLine(f.IsVpn);        // VPN service
Console.WriteLine(f.IsProxy);      // open / anonymizing proxy
Console.WriteLine(f.IsTorNode);    // Tor node
Console.WriteLine(f.IsDatacenter); // hosting / datacenter IP (often a bot)
Console.WriteLine(f.IsSpam);       // known spam source
Console.WriteLine(f.IsCrawler);    // known crawler / bot
Console.WriteLine(f.IsThreat);     // listed on a threat feed

if (f.IsVpn || f.IsProxy || f.IsTorNode)
{
    // require step-up verification (CAPTCHA, 2FA)
}

A dedicated check against the live Tor node list, with a count of matching nodes.

var tor = await client.TorCheckAsync("185.220.101.1");

Console.WriteLine(tor.IsTor);        // True
Console.WriteLine(tor.TorNodeCount); // number of matching Tor nodes