We've shipped sandbox support in Claude Code CLI to make the CLI safer and faster. From internal usage, we've found that using the sandbox reduces permission prompts by 84% so that you can focus on the most important permissions

Haiku 4.5 is a workhorse that makes the coding experience in Claude Code feel really fast. While Sonnet 4.5 remains the default, Haiku 4.5 now powers the Explore subagent which can rapidly gather context on your codebase to build apps even faster.