Claude Code version 2.1.251 introduces new hook events for model switching, live streaming of foreground subagent tool calls, and a spend limit bar in the usage interface. The update also changes the default model for seat-based Enterprise subscriptions to Opus 5.

  • Added PreModelSwitch and PostModelSwitch hook events and session staleness data to SessionStart resume hooks.
  • Fixed file tools following swapped symlinks inside working directories, preventing reads or writes outside approved locations.
  • Fixed plugin commands declared in marketplace entries pointing outside the plugin directory, rejecting such paths with a traversal error.
  • Fixed Grep and Glob not applying Read deny rules to files reached through symlinked search paths.
  • Changed the default model for seat-based Enterprise subscriptions to Opus 5, matching other premium plans.

These changes improve security by closing permission bypasses via symlinks and enhance usability with new hooks and clearer usage limits.