Claude docs changes for March 26th, 2026 [diff]

Executive Summary

  • PowerShell tool added for Windows as an opt-in preview, enabling Claude to run PowerShell commands natively instead of routing through Git Bash
  • Two new hook events: CwdChanged (fires on directory changes) and FileChanged (fires on watched file changes), both with CLAUDE_ENV_FILE support for environment reloading via tools like direnv
  • New allowedChannelPlugins managed setting lets Team/Enterprise admins restrict which channel plugins can deliver messages
  • Model configuration expanded for third-party providers: new env vars let admins customize display names and declare capabilities for pinned Bedrock/Vertex/Foundry models
  • VS Code extension gains a URI handler (vscode://anthropic.claude-code/open) to open Claude Code tabs from external tooling

New Claude Code versions

2.1.84

New features

  • Added PowerShell tool for Windows as an opt-in preview (CLAUDE_CODE_USE_POWERSHELL_TOOL=1)
  • Added ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_SUPPORTS env vars to override capability detection for pinned third-party provider models, plus _MODEL_NAME/_DESCRIPTION to customize the /model picker label
  • Added CLAUDE_STREAM_IDLE_TIMEOUT_MS env var to configure the streaming idle watchdog threshold (default 90s)
  • Added TaskCreated hook that fires when a task is created via TaskCreate
  • Added WorktreeCreate hook support for type: "http" — return the created worktree path via hookSpecificOutput.worktreePath
  • Added allowedChannelPlugins managed setting for Team/Enterprise admins to define a channel plugin allowlist
  • Added x-client-request-id header to API requests for debugging timeouts
  • Added idle-return prompt that nudges users returning after 75+ minutes to /clear
  • Deep links (claude-cli://) now open in your preferred terminal
  • Rules and skills paths: frontmatter now accepts a YAML list of globs

Existing feature improvements

  • MCP tool descriptions and server instructions are now capped at 2KB to prevent OpenAPI-generated servers from bloating context
  • MCP servers configured both locally and via claude.ai connectors are now deduplicated — the local config wins
  • Background bash tasks that appear stuck on an interactive prompt now surface a notification after ~45 seconds
  • Token counts ≥1M now display as "1.5m" instead of "1512.6k"
  • Global system-prompt caching now works when ToolSearch is enabled, including for users with MCP tools configured
  • Stats screenshot (Ctrl+S in /stats) is now 16× faster and works in all builds
  • Changed issue/PR references to only become clickable links when written as owner/repo#123 — bare #123 is no longer auto-linked
  • Slash commands unavailable for the current auth setup are now hidden instead of shown
  • [VSCode] Added rate limit warning banner with usage percentage and reset time

Major bug fixes

  • Fixed voice push-to-talk: holding the voice key no longer leaks characters into the text input
  • Fixed up/down arrow keys being unresponsive when a footer item is focused
  • Fixed Ctrl+U (kill-to-line-start) being a no-op at line boundaries in multiline input
  • Fixed null-unbinding a default chord binding still entering chord-wait mode
  • Fixed workflow subagents failing with API 400 when the outer session uses --json-schema
  • Fixed the "allow Claude to edit its own settings" permission option not sticking
  • Fixed MCP tool/resource cache leak on server reconnect
  • Fixed a startup performance issue with partial clone repositories (Scalar/GVFS)
  • Fixed native terminal cursor not tracking the text input caret (IME/CJK input)
  • Fixed spurious "Not logged in" errors on macOS from transient keychain failures
  • Fixed cold-start race where core tools could fail with InputValidationError on typed parameters

Claude Code changes

Changed documents

channels-reference [Source]

  • Added note that Team/Enterprise admins can use allowedChannelPlugins as an alternative to the official Anthropic allowlist for organization-specific channel plugins. [line 873] [Source]

channels [Source]

  • Rewrote enterprise controls section: channels now off by default for Team/Enterprise, with a two-setting model (channelsEnabled + allowedChannelPlugins). [lines 384-410] [Source]
  • New section documenting how to restrict which channel plugins can run via allowedChannelPlugins, including configuration example. [lines 415-430] [Source]

cli-reference [Source]

  • Added claude plugin command entry (manages Claude Code plugins; alias claude plugins). [line 21] [Source]

env-vars [Source]

  • Added ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_NAME, _DESCRIPTION, and _SUPPORTED_CAPABILITIES env vars for customizing pinned model display and capability declarations on third-party providers. [lines 14-24] [Source]
  • Added CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACK to disable fallback when streaming fails mid-stream (useful when a proxy causes duplicate tool execution). [line 56] [Source]
  • Added CLAUDE_CODE_SUBPROCESS_ENV_SCRUB to strip credentials from subprocess environments (Bash, hooks, MCP stdio), reducing prompt-injection exfiltration risk. [line 83] [Source]
  • Added CLAUDE_CODE_USE_POWERSHELL_TOOL to enable the PowerShell tool on Windows (opt-in preview). [line 89] [Source]
  • Updated CLAUDE_ENV_FILE description to mention CwdChanged and FileChanged hooks in addition to SessionStart. [line 92] [Source]

hooks-guide [Source]

  • New example section "Reload environment when directory or files change" showing how to use CwdChanged and FileChanged hooks with direnv. [lines 325-385] [Source]
  • Added CwdChanged and FileChanged to the event reference table. [lines 460-461] [Source]

hooks [Source]

  • Added CwdChanged hook event: fires when working directory changes (e.g., via cd), useful for reactive environment management with direnv. [lines 31-32] [Source]
  • Added FileChanged hook event: fires when a watched file changes on disk; matcher specifies which basenames to watch. [lines 31-32] [Source]
  • Added shell field to command hooks, accepting "bash" (default) or "powershell", to run individual hooks via PowerShell on Windows. [line 309] [Source]
  • Updated WorktreeCreate to support HTTP hooks: HTTP hooks return the worktree path via hookSpecificOutput.worktreePath instead of stdout. [lines 1637-1648] [Source]
  • CLAUDE_ENV_FILE is now available for CwdChanged and FileChanged hooks, allowing hooks to persist environment variables into subsequent Bash commands. [line 819] [Source]
  • New full reference sections for CwdChanged and FileChanged including input schemas, watchPaths output field, and usage examples. [lines 1714-1800] [Source]
  • New section "Windows PowerShell tool" with example for running hooks via PowerShell using "shell": "powershell". [lines 2469-2499] [Source]
  • SessionStart now documented as supporting only command hooks (previously listed alongside events that also support http/prompt/agent). [line 2206] [Source]

ide-integrations [Source]

  • New section documenting the VS Code URI handler vscode://anthropic.claude-code/open, including prompt and session query parameters for pre-filling prompts or resuming conversations from external tooling. [lines 216-253] [Source]

interactive-mode [Source]

  • Ctrl+F (kill all background agents) replaced by Ctrl+X Ctrl+K. [line 16] [Source]
  • Ctrl+G now also has Ctrl+X Ctrl+E as the readline-native binding for opening external editor. [line 19] [Source]
  • New Option+O / Alt+O shortcut to toggle fast mode. [line 31] [Source]
  • New "Transcript viewer" shortcuts section documenting Ctrl+E and exit keys. [lines 72-80] [Source]
  • Background task output is now written to a file and retrieved via the Read tool (previously buffered and retrieved via TaskOutput). [line 203] [Source]

keybindings [Source]

  • Added chat:killAgents action (default Ctrl+X Ctrl+K). [line 100] [Source]
  • Added chat:fastMode action (default Meta+O). [line 103] [Source]
  • chat:externalEditor now has two default bindings: Ctrl+G and Ctrl+X Ctrl+E. [line 106] [Source]
  • Added footer:up and footer:down actions for navigating the footer. [lines 219-220] [Source]

mcp [Source]

  • Added new remote MCP servers: Gainsight (Staircase AI), pg-aiguide (TimescaleDB/Tiger docs), and CB Insights.

memory [Source]

  • New AGENTS.md section explaining how to import an existing AGENTS.md into CLAUDE.md for cross-agent compatibility. [lines 100-115] [Source]
  • Block-level HTML comments in CLAUDE.md files are now stripped before context injection, allowing maintainer notes without spending tokens. [line 128] [Source]

model-config [Source]

  • Updated effort level documentation: max now persists only via CLAUDE_CODE_EFFORT_LEVEL env var (not across sessions via /effort); Sonnet 4.6 also defaults to medium effort; added guidance that medium is recommended for most coding tasks. [lines 144-154] [Source]
  • New section "Customize pinned model display and capabilities" documenting ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_NAME, _DESCRIPTION, and _SUPPORTED_CAPABILITIES env vars for third-party providers, with a capability values table. [lines 266-308] [Source]

monitoring-usage [Source]

  • OTEL_LOG_TOOL_DETAILS now also logs tool input arguments (file paths, URLs, search patterns, etc.) as a tool_input attribute, bounded to ~4K characters. [line 89] [Source]

plugins-reference [Source]

  • Added CwdChanged and FileChanged to the plugin hook events table. [lines 127-128] [Source]
  • New userConfig field: declares values Claude Code prompts users for at plugin enable time, stored in settings or system keychain. [lines 370-395] [Source]
  • New channels field: lets a plugin declare message channels bound to an MCP server, with per-channel userConfig. [lines 397-420] [Source]
  • Corrected path behavior: custom commands, agents, skills, and outputStyles paths now replace (not supplement) the default directory. [lines 422-430] [Source]
  • Added output-styles/ directory to the plugin structure and file locations reference. [lines 592-593] [Source]

sandboxing [Source]

  • Added note about sandbox.failIfUnavailable setting: when true, Claude Code fails at startup if sandbox cannot start, intended for managed deployments requiring sandboxing as a security gate. [line 101] [Source]

settings [Source]

  • Added useAutoModeDuringPlan setting to control whether plan mode uses auto mode semantics. [line 158] [Source]
  • Added defaultShell setting ("bash" or "powershell") for routing ! commands through PowerShell on Windows. [line 160] [Source]
  • Added allowedChannelPlugins managed setting (Team/Enterprise): allowlist of channel plugins that can push messages, replacing the Anthropic default list when set. [line 184] [Source]
  • Added sandbox.failIfUnavailable setting to make sandbox startup failures a hard error. [line 258] [Source]
  • Documented drop-in directory support for managed settings: managed-settings.d/*.json files are alphabetically sorted and merged on top of managed-settings.json. [lines 91-96] [Source]

setup [Source]

  • Added note about PowerShell tool opt-in preview for native Windows usage. [line 133] [Source]

skills [Source]

  • Updated /debug description: it now enables debug logging mid-session (logs are off by default unless started with --debug). [line 18] [Source]
  • Added shell frontmatter field (bash or powershell) for running inline shell commands in skills via PowerShell on Windows. [line 233] [Source]

sub-agents [Source]

  • Added initialPrompt frontmatter field: auto-submitted as the first user turn when the agent runs as the main session agent. [line 255] [Source]
  • Documented subagent model resolution order: CLAUDE_CODE_SUBAGENT_MODEL env var > per-invocation model parameter > subagent frontmatter model > main conversation's model. [lines 265-271] [Source]

tools-reference [Source]

  • Added PowerShell tool entry (Windows opt-in preview, requires CLAUDE_CODE_USE_POWERSHELL_TOOL=1). [line 23] [Source]
  • TaskOutput tool marked as deprecated; prefer Read on the task's output file path. [line 30] [Source]
  • New "PowerShell tool" section documenting how to enable, shell selection settings, and current preview limitations. [lines 47-90] [Source]

vs-code [Source]

  • New section documenting the VS Code URI handler vscode://anthropic.claude-code/open with prompt and session query parameters. [lines 216-253] [Source]

API changes

Changed documents

remote-mcp-servers [Source]

  • Added new remote MCP servers: tldraw (sketch/draw/diagram), Intuit QuickBooks (business finances), CB Insights (private company intelligence), Gainsight Staircase AI (customer context), pg-aiguide (PostgreSQL/Tiger docs), and MSCI (updated URL and description).