Use /model in Claude Code to see your current model and switch models. Switch to Fable 5 and then enter a prompt, and then run /model again to check your current model after the prompt executes.

Last night after almost every prompt it says...

  Fable 5's safeguards flagged this message. The safeguards are intentionally broad right now and may flag safe and routine coding, cybersecurity, or biology work. These measures let us bring you Mythos-level capabilities sooner, and we're working to refine them. Switched to Opus 4.8. Send feedback with /feedback or learn more