What survives

Termio’s one structural promise is that a session outlives the thing you were looking at it through. Close the window, quit the app, let it update itself, drop the SSH link to a VPS — the agent keeps working. This page is the honest version of that claim: what survives each event, what doesn’t, and what it costs when a process really does go away.

The rule

Every session runs inside termiod, the Termio server, on the machine that owns it — including the ones on this Mac. The app, the CLI, and the iOS app are all viewers. A viewer attaches to a session and detaches from it; it never holds the process.

So the question “does this kill my agent?” always reduces to one thing: did the process die, or did a viewer just let go? Only two things end a session on purpose — Close Session (⌘W), and the process exiting by itself.

What survives what

The top six rows are one event under six names: a viewer went away and the process didn’t notice. Reattaching repaints the screen from the server’s own scrollback, so you come back to the output you’d have seen if you had never left.

Detaching is the default

Nothing casual ends a session. Closing the window, quitting the app, a self-update, a laptop that lost Wi-Fi mid-ssh — every one of them detaches. The next launch reattaches to the sessions that are still there rather than starting new ones, which is why a long agent run is safe to walk away from.

Ending a session is the deliberate act: ⌘W closes the focused session, the way ⌘W closes a browser tab, and its pane collapses with it. Once no session is left, ⌘W closes the window and the app keeps running with everything else alive. See Keyboard shortcuts.

When the process really does go away

A server that stops — a reboot, a termiod stop, a box that lost power — takes its PTYs with it. There is no way around that; a process is a process. What Termio does is make coming back cheap:

• The tree is restored. Projects, worktrees, workspaces, split groups, and the session you left each workspace on all come back, because they live in a file rather than in the daemon.
• Sessions restart in their own directory. A shell comes back as a shell, rooted where it was.
• Agents on this Mac that can resume, do. Reopening a session relaunches the agent into the same conversation rather than a blank one.

Resume is exact-or-nothing: Termio either continues the precise conversation a session was bound to, or it starts fresh. It never guesses at a nearby one. Which agents can do this is a fact about each agent’s own CLI, declared in its manifest — see the resume column in Running multiple agents.

Surviving a reboot

Without a service, the server lives as long as your login session. That is usually fine on the Mac in front of you and almost never fine on a box you only ever reach over SSH, where nobody logs in interactively at all.

termiod service install    # launchd on macOS, systemd --user on Linux
termiod service status

With a service installed the server is brought back after a crash, and started again at login after a reboot. On Linux, surviving your logout also needs lingering enabled for the user (loginctl enable-linger); without it the unit stops with your session.

Be clear about what this buys: the server comes back, not the processes it was holding. A reboot still ends every PTY on that machine. A service is what stops “nothing is listening on that box” from being a permanent state — see Troubleshooting.

Sleep

A sleeping machine isn’t running anything, so the honest rule for a laptop is: sessions don’t die when the Mac sleeps, they pause with it and pick up when it wakes.

Termio does hold the machine out of idle sleep while there is work worth protecting. While any session is working or waiting on you, the server renews a short caffeinate lease, so a Mac plugged into power stays reachable for the agent that went quiet on a permission prompt — exactly the moment your phone needs to answer it. On battery it takes no lease at all, and closing the lid sleeps the machine regardless: nothing in user space can override clamshell sleep.

Updating without dropping sessions

A new server build replaces the running one in place: the process keeps its id and its PTYs, and the sessions never notice.

termiod handoff

That is also what happens when the app updates itself, which is why a Termio update doesn’t cost you your running agents. A machine being set up or updated from Settings ▸ Remote Hosts takes the same path, and an update that would interrupt work in progress says so and names the session first.

What Termio does not keep

Being clear about the edges is part of the promise:

• Termio keeps no transcript of your terminals. Scrollback lives in the server for the session’s lifetime and goes away with it; nothing durable is written. The one exception is a handoff, which passes each session’s replay buffer to the incoming server through a temporary file it unlinks as it goes — in flight for the length of an update, never a stored record.
• An agent’s conversation belongs to the agent. Resume works by handing the agent back its own session id; the conversation is in the agent’s store, under your own account, exactly as it would be from a plain terminal.
• Nothing syncs anywhere. State is per machine, on that machine. There is no Termio cloud holding a copy — see Devices.