What quitting Spaces, restarting a machine, or updating does to your workspaces, and how agents come back afterward.
Quitting the Mac app asks what to do with this Mac's work: "Quit and Keep Running" (the default) leaves every workspace, process, terminal, and agent running on this Mac; "Stop All and Quit" stops this Mac's workspaces and ends its ad hoc terminals and agents first; "Cancel" leaves Spaces open. Neither option touches a paired remote device, which keeps running Spaces or not on its own.
Restarting or shutting down a device ends every terminal, process, and agent running on it, the same as the Spaces service on that device crashing. Logging out of the macOS account on a Mac does the same, since the Spaces service runs in that login session. Logging out of a Linux machine does not: the installer enables lingering, so the Spaces service and everything running under it keep going without a login session open (see install on Linux). Configured processes stay stopped until you start the workspace again. A pane whose session was lost this way shows "Session failed. The process stopped unexpectedly." and stays read-only until you start that target again (see start, stop, and restart).
A device keeps a record of the coding agents its work was cut short on: by a restart, logout, shutdown, a crash, or "Stop All and Quit". Stopping a single workspace or a single agent yourself records nothing, since that is a deliberate end. On the next launch, or as soon as a device reports a record while Spaces is running, Spaces offers "Restore all" or "Skip" on both the Mac and the iPhone.
Restoring relaunches each agent in the workspace and pane it was in, resuming its conversation when the agent supports that. An agent started as a one-shot run, such as claude -p, codex exec, or opencode run (but not opencode run -i, which resumes), has no conversation to resume, so it comes back as another run of the same command instead.
Applying an update to the Mac app or to a device's Spaces service does not end its sessions: workspaces, processes, terminals, and agents keep running through it. See updates.
A session that has ended, whether it exited cleanly, failed, or was closed, stays listed with its transcript viewable for seven days, up to 2 GB of ended-session data per device. Past either limit, the oldest ended sessions are removed first.
