[Release] anthropics/claude-code v2.1.90: v2.1.90

Claude Code v2.1.90 introduces the `/powerup` interactive lesson feature, adds environment variable support for offline marketplace caching, and delivers significant bug fixes and performance improvements. Key fixes address rate-limit dialog crashes, prompt-cache misses with deferred tools, file editing conflicts, and auto-mode boundary violations. Performance enhancements include quadratic slowdown elimination in SDK sessions and SSE transport optimization.

Key Points

• •New `/powerup` command provides interactive lessons with animated demos for Claude Code features
• •Added `CLAUDE_CODE_PLUGIN_KEEP_MARKETPLACE_ON_FAILURE` env var to maintain marketplace cache during offline git pull failures
• •Fixed infinite loop causing rate-limit dialog to repeatedly auto-open and crash sessions
• •Resolved `--resume` prompt-cache miss regression affecting users with deferred tools, MCP servers, or custom agents
• •Fixed file editing failures when PostToolUse format-on-save hooks rewrite files between consecutive edits
• •Auto mode now properly respects explicit user boundaries and constraints
• •Eliminated quadratic performance degradation in SDK sessions with long conversation transcripts
• •Improved `/resume` all-projects view with parallel session loading for faster load times
• •Hardened PowerShell tool permission checks against background job bypass and archive extraction vulnerabilities
• •Removed DNS cache commands from auto-allow list for improved privacy

Workflow Diagram

Concepts

Artifacts (1)

CLAUDE_CODE_PLUGIN_KEEP_MARKETPLACE_ON_FAILURE=true