This setting uses Claude Opus 4.1 for plan mode and Claude Sonnet 4 for all other work - getting the best of both models while maximizing your usage.
To try it out, select “Opus Plan Mode” in the model selector (/model). You get the benefit of Opus 4.1’s intelligence for planning and Sonnet 4’s speed (and lower cost) for execution.
As a reminder, you can toggle between modes (default, auto-accept, and plan) with Shift+Tab. This setting is available now to all Claude Code users with Opus access in the latest Claude Code update.