Scoped to the session, not saved as a setting

Plan mode is scoped to the current session rather than being a persistent setting you turn on once and forget about. It needs to be entered explicitly with /plan each time you actually want it.

Once active, it stays active across as many messages as you send until you explicitly exit it, which lets you go back and forth refining exactly what you are asking for before committing to anything, the entire back-and-forth happening without a single file changing in the meantime.

This session-scoping is deliberate: unlike auto-approve or effort level, plan mode is meant to be a conscious choice made for a specific piece of work, not a standing mode you might forget was left on.

There is no equivalent of auto-approve for plan mode itself, no setting that starts every future session already in plan mode by default. Each time you want the batched-review behavior, entering it explicitly with /plan is the only way to get it.

Starting a new session after exiting plan mode in a previous one begins in the normal mode, not wherever the last session left off; plan mode never carries forward as a leftover state from a prior conversation.