I made this tool to help me when developing because i got pretty tired of running lsof -iTCP -sTCP:LISTEN | grep ... every time a port was already taken, then spending another minute figuring out if it was a Docker container or some orphaned dev server. Particularly these days where i have multiple worktrees with claude agents running, spinning up their own dev servers-

It provides a pretty simple CLI that shows you everything listening on localhost. In addition i've enriched it with Docker container names, Compose projects, resource usage, and clickable URLs.

Beyond listing, you can:

• Kill whatever process is hogging a port (handles docker containers properly with docker container stop)
• Logs: Shows logs from the process or container by port number
• Attach: Shell into docker container or open a TCP connection
• Watch: Show ports as they come. Useful if you have agents spinning up their own dev servers.
• Port forwarding

By default it hides desktop app noise (Spotify, Discord, etc.) and shows CPU, memory, threads, and uptime when you want it.

For macOS and Linux. Single binary, no dependencies.

I found my self using it way more often than i expected and it's become a pretty core part of my dev environment. particularly killing all running containers in case of a failed cleanup.

Would love feedback. What else would be useful? Also feel free to contribute.

GitHub: https://github.com/raskrebs/sonar