[Release] anthropics/claude-code v2.1.210: v2.1.210

Claude Code v2.1.210 is a maintenance release focused on stability, UX improvements, and bug fixes. Key improvements include a live elapsed-time counter for long-running tools, enhanced permission warnings, fixes for isolation and session management issues, and better handling of edge cases in tool rendering and MCP server management. The release addresses 40+ bugs spanning tool execution, UI rendering, file handling, and background worker reliability.

Key Points

• •Added visual feedback for long-running tool calls with a live elapsed-time counter to prevent appearance of being stuck
• •Implemented startup warnings for deprecated permission rules (Write/NotebookEdit/Glob) directing users to use Edit/Read instead
• •Fixed critical isolation bug where worktree subagents could mutate the main repo instead of their isolated copy
• •Resolved ultracode keyword opt-in firing on non-human input like webhooks and relayed PR comments
• •Fixed session crashes caused by tool renderers returning numeric bigints or plain text instead of UI elements
• •Improved claude attach reliability by adding daemon settlement waiting and deferred terminal resize application
• •Fixed background worker crash-loops when clients reset connections to the background service
• •Enhanced permission classifier to default to Sonnet 5 for external sessions with validation on first request
• •Improved dataviz skill with perceptual OKLab color difference validation and recalibrated color-blindness thresholds
• •Fixed multiple file handling issues including temp file cleanup on Windows/network filesystems and git worktree lock leaks

Workflow Diagram

Concepts