Claude Code Release Notes

Claude Code v2.1.21 Release Notes

Claude Code v2.1.21 introduces Japanese IME support, Python virtual environment automation, and critical bug fixes for improved development workflow.

January 28, 2026 • 2 min read • By Claude World

The Claude Code team has released v2.1.21, bringing enhanced internationalization support and significant workflow improvements for developers worldwide. This update focuses on better Japanese language support, automated Python environment management, and several critical bug fixes.

What’s New

Enhanced Japanese Language Support

The most notable addition is full-width (zenkaku) number input support from Japanese IME in option selection prompts. This improvement makes Claude Code more accessible to Japanese developers by properly handling native number input methods.

Automated Python Virtual Environment Management

VS Code users now benefit from automatic Python virtual environment activation. Claude Code will automatically ensure that python and pip commands use the correct interpreter from your project’s virtual environment. This feature is configurable via the claudeCode.usePythonEnvironment setting.

Improved Tool Preference

Claude now intelligently prefers file operation tools (Read, Edit, Write) over bash equivalents (cat, sed, awk), resulting in more reliable and consistent file operations across different operating systems.

Enhanced Progress Indicators

Progress indicators have been improved to show “Reading…” while operations are in progress and “Read” when complete, providing clearer feedback during file operations.

Critical Bug Fixes

  • Shell completion cache files no longer get truncated on exit
  • API errors during session resumption after interrupted tool execution have been resolved
  • Auto-compact triggering has been fixed for models with large output token limits
  • Task ID reuse after deletion has been prevented
  • File search functionality now works properly in the VS Code extension on Windows
  • VS Code message action buttons now display with correct background colors

How to Update

To update to Claude Code v2.1.21:

  1. VS Code Extension: Update through the Extensions marketplace or enable auto-updates
  2. CLI Tool: Run your package manager’s update command
  3. Manual Installation: Download from the release page linked below

Restart VS Code after updating to ensure all new features are properly activated.