Claude Code /effort Command: Three-Tier Thinking Control with Per-Turn Ultrathink Override
Claude Code Changelog·high signal
Claude Code v2.1.76 adds the /effort command with three levels (low/medium/high), replacing the old max level. Opus 4.6 now defaults to medium effort for Max and Team subscribers. The 'ultrathink' keyword in a prompt temporarily bumps effort to high for a single turn without changing the persistent setting — ideal for complex debugging without paying the reasoning cost on every message.