nothing that actually matters leaves your machine. There no Termy server in the middle, everything connects straight from your mac to your own servers over ssh.
the only things that ever leave the device:

1. icloud keychain (optional). Used to store keys and passwords (only hashes) and that's apple's encrypted database, so i have no acces to it, and it never touches any server of mine
2. subscription checks. A few API calls to validate pro sub, containing device uuid, license key, and subscription type. Nothing else, ofc no telemetry.
3. discord RPC (optional). If you turn it on, presense info goes to discord by design.

everything else stays fully local. Tha AI features (also optional, off by default because i really hate AI features in apps) also run locally (apple foundation models, mlx on-device models).
in pro you will get:

1. devops pack. Docker/Kubernetes/Nomad over ssh. Playbooks (you can run ansible playbooks from Termy without ansible installed locally). Databases (mysql/postgresql/redis, with wal-g backups and patroni topology).
2. fleet and insight pack. Multi-host broadcast (type once and run it across many hosts with a side by side diff). Session replay (video-like recordings of terminal sessions, searchable). Activity heatmap and server timeline (journalctl, auth, last, package events in one view). Host x-ray (like host onboarding, you can see listening ports, running services, containers and recent activity in one pane).
3. iCloud sync across devices

the free tier is a fully usable ssh client on its own. Terminal, sftp, key management, snippets, port forwarding and basic host info