tailcat
Netcat-style encrypted tunnels between two machines, no account needed
What it is
Tailcat reuses Tailscale's open-source data plane to open WireGuard-encrypted point-to-point connections between two machines, bootstrapping through a DERP relay and switching to direct UDP after NAT traversal when it can. Connection details are shared out of band as a short address, so no Tailscale account, control server, or root access is required. It can pipe stdin/stdout, forward and expose TCP ports, act as an exit node, run a built-in SSH server, and send files from a browser demo. Developers and admins use it as a CLI or Go library to reach machines behind NAT without changing routing or DNS.