rathole

Rathole punches a hole through without opening ports on your router. It's essentially a tunnel from your private network to a public endpoint.

Written in Rust, so it's fast and lightweight. We're talking single-digit MB of RAM. Compared to frp (the other big player here), rathole uses less memory and handles more concurrent connections. Setup is straightforward: a config file on the server side, a config file on the client side, done.

Everything is free. No paid tier, no cloud service, no catch on features. You self-host both ends. Docker image available, or grab the binary.

The catch: you need a server with a public IP to act as the relay. If you don't already have a VPS, that's $5/mo minimum. And the docs are thin: the README covers the basics but you'll be reading config examples more than prose. Solo devs and home labbers, this is your tool. Teams needing managed tunnels with dashboards should look at Cloudflare Tunnel (free) or ngrok instead.