tmate

tmate is a session sharer that is based on tmux and relays your terminal through SSH via nodes. It works behind NAT without firewall tweaks. A single command shows a writable and optional read-only connection string.

Features of tmate include SSH tunnelling, automatic reconnection on IP change and named sessions bound to your API key. You can embed an authorized_keys list to restrict access, generate links, and capture logs with tmate show-messages. 

Foreground daemon mode keeps headless servers reachable, while config mirrors tmux options, macros, and keybindings. Self-hosting is possible through the tmate-ssh-server container, which supports multi-region failover.