Claude docs changes for February 22nd, 2026 [diff]

Executive Summary

  • Two new hook events (WorktreeCreate and WorktreeRemove) enable worktree lifecycle customization and support for non-git version control systems (SVN, Perforce, Mercurial) in isolated sessions
  • Subagents can now use worktree isolation via isolation: worktree in their frontmatter, allowing parallel work without conflicts
  • New claude agents CLI command lists all configured subagents grouped by source without starting an interactive session
  • New CLAUDE_CODE_DISABLE_1M_CONTEXT environment variable allows disabling 1M context window support in enterprise environments

Claude Code changes

Changed documents

CLI Reference [Source]

  • New claude agents command added that lists all configured subagents, grouped by source. [line 13] [Source]

Common Workflows [Source]

  • New "Subagent worktrees" section: subagents can now use worktree isolation to work in parallel without conflicts by adding isolation: worktree to the agent's frontmatter. Each subagent gets its own worktree that is automatically cleaned up when done. [lines 1006-1009] [Source]
  • New "Non-git version control" section: worktree isolation can now support non-git VCS (SVN, Perforce, Mercurial) via WorktreeCreate and WorktreeRemove hooks that replace the default git behavior. [lines 1049-1052] [Source]

Hooks Guide [Source]

  • Two new hook events documented: WorktreeCreate (fires when a worktree is being created, replaces default git behavior) and WorktreeRemove (fires when a worktree is being removed). [lines 369-370] [Source]
  • SessionStart hook source now includes clear as a valid value in addition to startup, resume, and compact. [line 402] [Source]
  • ConfigChange event now documented as supporting matchers on configuration source (user_settings, project_settings, local_settings, policy_settings, skills). [line 501] [Source]
  • Updated list of hook types supported per event: clarified which events support command, prompt, and agent hooks vs. command-only hooks. [lines 505-525] [Source]

Hooks [Source]

  • Two new hook events added to the events table: WorktreeCreate and WorktreeRemove, with full documentation including input/output schemas and examples. [lines 29-30] [Source]
  • WorktreeCreate hook must print the absolute path to the created worktree directory on stdout; non-zero exit causes creation to fail. WorktreeRemove hook failures are only logged in debug mode. [lines 503-504] [Source]
  • WorktreeCreate and WorktreeRemove added to the no-matcher list (always fire on every occurrence). [line 187] [Source]
  • ConfigChange added to the block decision model events (using "block" decision value). [line 557] [Source]
  • Full new sections for WorktreeCreate and WorktreeRemove hook events with input schemas and usage examples for non-git VCS (SVN example). [lines 1511-1622] [Source]
  • Updated prompt-based hooks section to clearly delineate which events support all three hook types (command, prompt, agent) vs. command-only events. [lines 1692-1715] [Source]

Model Config [Source]

  • New CLAUDE_CODE_DISABLE_1M_CONTEXT environment variable documented: setting it to 1 disables 1M context window support and removes 1M model variants from the model picker. [line 166] [Source]

Settings [Source]

  • New CLAUDE_CODE_DISABLE_1M_CONTEXT environment variable added: disables 1M context window support; useful for enterprise environments with compliance requirements. [line 894] [Source]

Sub-agents [Source]

  • Documented that claude agents CLI command lists all configured subagents from the command line (grouped by source, showing overrides) without requiring an interactive session. [line 160] [Source]