Sessions
Sessions belong to the Mac app, not the window: each turn records intent, tool calls, approvals, changes and cost, and survives a closed window.
Verified core. Implemented and tested as a foundation; not necessarily a complete public journey.
The host owns the session
A session belongs to the native host and its project, not to a window. The window can close and reopen without losing accepted work.
This also means the website never implies a cloud agent: sessions run on your Mac.
A visible turn boundary
A turn separates intent, model output, tool calls, approvals and the resulting changes. A pending approval stays part of the session until you decide.
Every turn records its cost. Reports what the provider or local runtime exposes; a provider that hides usage shows a dash, never a guess.
What durability does not mean
Context limits and provider behavior still vary. An interrupted provider request cannot be made to finish, and not every model supports every tool.