Claude Code v2.1.90 Release Notes

Claude Code v2.1.90 introduces interactive PowerUp lessons, performance improvements, and critical bug fixes for a smoother coding experience.

April 2, 2026 • 10 min read • By ClaudeWorld

Claude Code v2.1.90 brings exciting new learning features alongside significant performance improvements and important bug fixes that enhance the overall development experience.

What’s New

🚀 Interactive PowerUp Lessons

The standout feature of this release is the new /powerup command, which provides interactive lessons with animated demos to help you master Claude Code features. This gamified learning approach makes it easier than ever to discover and understand the full capabilities of your AI coding assistant.

🔧 Environment & Configuration Improvements

  • Offline Support: New CLAUDE_CODE_PLUGIN_KEEP_MARKETPLACE_ON_FAILURE environment variable maintains marketplace cache when git operations fail, perfect for offline development environments
  • Protected Directories: Added .husky to protected directories in acceptEdits mode, preventing accidental modifications to Git hooks
  • Resume Functionality: Improved /resume performance with parallel project loading and cleaner session filtering

🐛 Critical Bug Fixes

  • Rate Limit Dialog: Fixed infinite loop crash when rate-limit dialog repeatedly opened after hitting usage limits
  • Prompt Cache: Resolved cache misses on --resume for users with deferred tools, MCP servers, or custom agents
  • File Editing: Fixed “File content has changed” errors during consecutive edits when format-on-save hooks modify files
  • Auto Mode: Enhanced respect for explicit user boundaries and instructions
  • UI Stability: Multiple interface crash fixes and improved visibility on light themes

⚡ Performance Enhancements

  • Eliminated quadratic slowdowns in SSE transport for large streamed frames
  • Optimized SDK session transcript writes for long conversations
  • Reduced per-turn JSON processing overhead for MCP tool schemas

🔒 Security Hardening

Strengthened PowerShell tool permission checks, closing several potential bypass vulnerabilities and improving parsing reliability.

How to Update

To update to Claude Code v2.1.90:

  1. Via Package Manager: Run your standard update command
  2. Manual Download: Visit the release page and download the latest version
  3. Auto-Update: Enable automatic updates in your Claude Code settings

After updating, try the new /powerup command to explore interactive lessons and discover features you might have missed!