Claude Code v2.1.133 Release Notes

Claude Code v2.1.133 introduces enhanced worktree management, improved sandbox configuration, and critical bug fixes for enterprise workflows.

May 8, 2026 • 10 min read • By ClaudeWorld

The Claude Code team is excited to announce the release of version 2.1.133, bringing significant improvements to worktree management, sandbox configuration, and overall stability for power users and enterprise environments.

What’s New

Enhanced Worktree Management

The most significant addition is the new worktree.baseRef setting, allowing you to choose whether --worktree, EnterWorktree, and agent-isolation worktrees branch from origin/<default> or local HEAD. You can set this to either fresh or head. Important note: The default fresh setting changes EnterWorktree’s base back to origin/<default> (reverting behavior from v2.1.128). If you need to keep unpushed commits in new worktrees, set worktree.baseRef: "head".

Improved Sandbox Configuration

Linux and WSL users now have more control over their sandbox environment with two new managed settings:

  • sandbox.bwrapPath: Specify custom bubblewrap binary locations
  • sandbox.socatPath: Define custom socat binary paths

Enhanced Hook System

Hooks now receive more context about the current execution environment. They can access the active effort level through:

  • effort.level JSON input field
  • $CLAUDE_EFFORT environment variable
  • Direct access in Bash tool commands via $CLAUDE_EFFORT

Administrative Improvements

A new parentSettingsBehavior admin-tier key ('first-wins' | 'merge') gives administrators control over how SDK managedSettings integrate with policy merge behavior.

Performance and Stability

This release includes several performance improvements:

  • Better focus mode behavior
  • Optimized memory usage by releasing warm-spare background workers under memory pressure
  • Fixed parallel session credential conflicts that caused 401 errors
  • Resolved various file handling issues including drive root matching and network drive access

Bug Fixes

  • Fixed Edit/Write allow rules incorrectly matching drive roots (C:\ or /)
  • Resolved file lock issues caused by clock skew or slow disk operations
  • Fixed spurious error notifications during conversation compaction
  • Improved proxy and mTLS support for MCP OAuth flows
  • Better Remote Control integration with claude.ai
  • Fixed effort level synchronization across concurrent sessions
  • Resolved subagent skill discovery issues
  • VSCode extension improvements for unsupported platform handling

How to Update

To update to Claude Code v2.1.133:

  1. Check your current version: claude --version
  2. Download the latest release from the official repository
  3. Follow the standard installation procedure for your platform
  4. Review the worktree.baseRef setting if you use worktree functionality
  5. Configure new sandbox paths if needed (Linux/WSL users)