Build a free network scanner app for Mac and Windows without writing code

Reddit user u/Lone_Wolf_555, a network engineer, wanted a scanner that lists every device on a subnet with IP, MAC, maker, a real name and device type. Claude Code wrote nearly all of it: a SwiftUI app for Mac and a Tauri port with a Rust scan engine for Windows. The app names devices from DHCP, UPnP, SNMP, web page titles and Ubiquiti discovery, guesses device types, saves scans per customer or site, draws a network map from a UniFi controller and exports to Excel. The poster's part was knowing what a good scan looks like and saying when something was wrong. Claude ran the tests, watched the GitHub Actions builds and tried the UI in a browser against demo data before handing it over, and showed mockups before building screens.

The app shipped free at arpradar.com. When the Windows builds kept failing, Claude worked out that GitHub's download servers were timing out, stopped re-running builds that burned minutes, and waited until downloads had stayed up for several checks before starting one. One commenter said it found every device on their LAN quickly. Apple signing was still a couple of weeks away when posted.

Claude could not see the real network from its sandbox, so anything about live scanning was tested by the poster, who also entered API keys by hand. Commenters noted that ARP only works inside one broadcast domain, so remote VLANs give IPs and ports but no MAC addresses, and that a closed-source scanner from an unknown developer is a hard sell; the poster said they may open source it.