Claude docs changes for May 8th, 2026 [diff]

Executive Summary

• Claude Code 2.1.133 adds hooks access to the active effort level via effort.level JSON and $CLAUDE_EFFORT env var, enabling hooks to react to the current reasoning effort setting
• New worktree.baseRef setting lets users control whether new worktrees branch from origin/<default> or local HEAD, with a notable behavior change: EnterWorktree now defaults back to origin/<default>
• C# SDK gains full webhook support with BetaWebhooks helpers for verifying signatures and parsing all session and vault event payloads
• Multiple significant bug fixes in 2.1.133, including parallel sessions losing credentials after token refresh races and subagents failing to discover skills

New Claude Code versions

2.1.133

New features

• Added worktree.baseRef setting (fresh | head) to choose whether --worktree, EnterWorktree, and agent-isolation worktrees branch from origin/<default> or local HEAD. Note: the default fresh changes EnterWorktree's base back to origin/<default> (it had been local HEAD since 2.1.128) — set worktree.baseRef: "head" to keep unpushed commits in new worktrees
• Added sandbox.bwrapPath and sandbox.socatPath managed settings (Linux/WSL) for specifying custom bubblewrap and socat binary locations
• Added parentSettingsBehavior admin-tier key ('first-wins' | 'merge') to let admins opt SDK managedSettings (parent tier) into the policy merge
• Hooks now receive the active effort level via the effort.level JSON input field and the $CLAUDE_EFFORT environment variable; Bash tool commands can also read $CLAUDE_EFFORT

Existing feature improvements

• Improved focus mode behavior
• Improved memory usage by releasing warm-spare background workers under memory pressure
• claude --help now lists --remote-control alongside --remote-control-session-name-prefix

Major bug fixes

• Fixed parallel sessions all dead-ending at 401 after a refresh-token race wiped shared credentials
• Fixed Edit/Write allow rules scoped to a drive root (C:\) or POSIX / matching incorrectly and always prompting
• Fixed an unhandled rejection (ECOMPROMISED) when a history or session-log file lock is compromised by clock skew or slow disk
• Fixed pressing Esc during conversation compaction showing a spurious "Error compacting conversation" notification
• Fixed HTTP(S)_PROXY / NO_PROXY / mTLS not being respected for the full MCP OAuth flow including discovery, dynamic client registration, token exchange, and token refresh
• Fixed Read/Write/Edit being denied on mapped network drives passed via --add-dir / SDK additionalDirectories
• Fixed Remote Control stop/interrupt from claude.ai not fully canceling the CLI session the same way local Esc does, causing queued messages to never advance after interrupting a stuck tool or prompt
• Fixed /effort in one session unexpectedly changing the effort level of other concurrent sessions, and a related issue where an IDE effort change could be silently dropped
• Fixed subagents not discovering project, user, or plugin skills via the Skill tool
• [VSCode] Fixed claudeCode.claudeProcessWrapper failing with "Unsupported platform" when the extension build doesn't bundle a Claude binary

Claude Code changes

Changed documents

index [Source]

• Removed the inline installation UI snippet (platform tabs for Terminal/Desktop/VS Code/JetBrains, OS selector, and the curl install command) from the top of the overview page

API changes

New Documents

api/csharp/beta/webhooks [Source]

New C# SDK reference page documenting the BetaWebhooks helpers for receiving and verifying webhook events. Covers the unwrap method for signature verification and payload parsing, and lists all supported data.type values for session lifecycle events (session.created, session.running, session.idled, etc.) and vault/credential events (vault.created, vault_credential.refresh_failed, etc.).

Changed documents

api/csharp/beta [Source]

• Added a new BetaWebhooks section with full C# class definitions for all webhook event types, including BetaWebhookEvent, BetaWebhookEventData (union type), UnwrapWebhookEvent, and the full set of session and vault/credential event data classes [line 43927] [Source]