Claude Code has shifted toward giving users more granular control over how Claude works — tuning effort levels, customizing interface behavior, and enabling powerful features like background agents and comprehensive code review. The /effort command now spans from low to max with interactive tuning, auto mode matches terminal themes, and /ultrareview runs cloud-based multi-agent code critique. Teams and enterprise customers gained OS certificate store trust by default, subprocess sandboxing with PID namespace isolation on Linux, and the ability to create managed policy fragments in managed-settings.d/. The product also expanded automation: /loop handles recurring intervals with cron scheduling, /powerup teaches features via animated lessons, and background agents (spawned as tasks with dependency tracking) run independently while the main session continues. Memory and session handling improved significantly—auto-memory now persists useful context, /recap provides context when returning to sessions, and prompt caching got longer TTLs (1-hour option available via environment variable). Plugin infrastructure matured with monitor support for background events, conditional hook execution via if fields, and persistent state via ${CLAUDE_PLUGIN_DATA}. A batch of security fixes hardened bash tool permission handling against environment-variable and network-redirect bypasses, while terminal rendering shifted to flicker-free mode and pull-based status updates reduced CPU churn.