Anthropic adds experimental Code Mode to Claude Code

Anthropic released Claude Code v2.1.323, which introduces Code Mode, an experimental opt-in in which Claude writes JavaScript to call its tools; the linked documentation explains how to enable it, or turn it off for an entire organization. Plugins can now declare an engines["claude-code"] version range in plugin.json, so plugins outside that range are not installed, updated or loaded, and installs choose the newest version that fits. The claude plugin validate command now type-checks a plugin's TypeScript hooks module and reports findings as warnings, with --strict making them fail. The release also fixes session, sign-in and resume bugs and adds .docx support for Artifact tool uploads.