v2.1.221 Claude Code Release Notes

Aug 4, 2026Source: Anthropic changelog

Claude's Analysisby Sonnet 4.6

VS Code's new Focus view (Ctrl+Alt+F) hides tool noise; this fix-heavy release also patches a zsh permission bypass and steadies Windows, MCP, and plugin reliability.

Changes

Total Changes (vs Average)

3.3×

Version Type

Patch

Release Focus

Mixed

Days Since Prior Release

Release # This Month

#1 of 1

Bug Fix Ratio

44%

Post-Release Edits

—

Change Category

Ecosystem Impact

MCP, Windows, and Plugins/Skills have each appeared in 8-9 of the last 10 releases, showing a sustained multi-release hardening push, while VS Code resurfaces for its first new feature in several releases.

Key Themes

1VS Code Focus View|4Security & Sandbox Hardening|5MCP & Session Reliability|5Plugin Workflow Changes|1Breaking: Gateway Model Validation

May Help If You've Noticed

Vim mode loses your yanked text after using history search or the transcript view

Added4 changes

•[VSCode] Added Focus view: a chat-menu toggle that hides tool activity behind an expandable per-turn summary with a live running-tool indicator, toggled with Ctrl+Alt+F or the "Claude Code: Toggle Focus view" command
•Added mode: "mask" for sandbox credential files on Linux and WSL — sandboxed commands read a sentinel copy (the whole file, or just the spans captured by an extract regex) while the sandbox proxy substitutes the real value on egress; on macOS file masking falls back to deny
•Added warnings to claude plugin validate when a marketplace or plugin name would be rejected by Claude Desktop's managed marketplace sync
•Added a prompt-audit subcommand to the claude-api skill for auditing prompts and tool descriptions for patterns written for older models

Improved6 changes

•Improved tool search on Google Vertex AI: re-enabled for Claude 4.5-generation and newer models
•Improved auto mode: permission checks for parallel tool calls are now cache-efficient, and switching modes while a check is pending reliably prompts instead of applying the stale result
•Reduced prompt-cache costs for auto-mode permission checks by reusing the cached conversation prefix across decisions
•Improved Stats panel to count cache tokens in its token totals, with a breakdown by input, output, cache read, and cache write
•Improved /ultrareview error messages when a repo shares no history with its base: a checkout with no branches is now refused up front with advice to create one, and refusal hints no longer suggest git fetch --unshallow on clones that are already complete
•Improved Windows startup: process creation times are now read via a native kernel32 call instead of spawning PowerShell, so endpoint security tools that gate powershell.exe no longer prompt

Fixed17 changes

•Fixed a Bash tool permission-check bypass where zsh could execute hidden commands in [[ ]] regex conditionals; affected commands now prompt for permission
•Fixed PowerShell permission checks mishandling paths containing quote characters on Windows; such paths now prompt for approval
•Fixed the thinking toggle having no effect for the rest of a session that started with thinking off; disabling an MCP server mid-connect no longer silently reverts
•Fixed MCP servers from --mcp-config not being connected before the first turn in print mode (-p), which made the model emit tool calls as literal text
•Fixed @-mentioned files being silently dropped when pressing Esc to retract a prompt and resubmitting it
•Fixed a crash when preparing API requests for SDK MCP tools named after built-in object properties such as constructor
•Fixed WebSearch failing with a 400 error at effort xhigh/max when thinking is disabled
•Fixed sandboxed large uploads failing with TLS errors through the sandbox proxy
•Fixed Team and Enterprise spend-limit message incorrectly blaming the org's monthly limit instead of your individual spend limit
•Fixed Bedrock authentication with AWS SSO named profiles failing in desktop-managed sessions on Windows machines that set a stray HOME environment variable
•Fixed CLAUDE_CODE_RESUME_INTERRUPTED_TURN=0 not disabling interrupted-turn auto-resume; falsy values are now honored
•Fixed a rare wake-from-sleep race where two Claude Code processes could both refresh the same MCP connector or WIF OAuth token at once, forcing re-authentication
•Fixed renaming a session from Claude Code Desktop or claude.ai not updating the CLI's session name; session names from every rename surface are now sanitized
•Fixed plugin- and org-delivered skills named after terminal-only built-ins (e.g. /help, /feedback) being un-invocable in non-interactive sessions
•Fixed the "Plugins changed" notification lingering after plugins were reloaded instead of clearing
•Fixed Vim mode: the yank register now survives dialogs, history search, and the transcript view instead of being silently emptied
•Fixed Vim mode: undoing back to an empty prompt now arms the "press ← again" confirm before returning to the agent view

Changed11 changes

•Changed background sessions to commit and push to preserve work, open a draft PR only when the task calls for one, follow your CLAUDE.md git instructions, and always end by reporting where the work lives
•Changed /plugin install to refresh a stale marketplace catalog and retry before reporting a plugin not found
•Changed plugins installed from /plugin to activate immediately when safe, instead of always requiring /reload-plugins
•Changed plugins to accept "." as a skills path, and the root-level SKILL.md validation error now suggests using the plugin root
•Changed /status to show the session kind: interactive, or a background job that is attached or unattended
•Changed emoji autocomplete to accept common alternate shortcodes like :thumbsup:, :thumbsdown:, and :love:
•Changed sessions forked with /fork to create a new worktree of their own instead of working in the original session's checkout
•Changed Claude in Chrome to close the browser tabs it opens once it no longer needs them
•Changed fast mode to report on the stream when usage credits run out mid-session, instead of failing silently
•Changed Monitor: a watch that exits without producing any output now says so instead of reporting "stream ended"
•Changed the Gateway model field validation: non-string values are rejected with a 400 instead of being forwarded

Removed1 change

•Removed the repeated "Permission mode changed while the auto-mode classifier call was queued" notice from approval prompts

Added4 changes

•[VSCode] Added Focus view: a chat-menu toggle that hides tool activity behind an expandable per-turn summary with a live running-tool indicator, toggled with Ctrl+Alt+F or the "Claude Code: Toggle Focus view" command

•Added mode: "mask" for sandbox credential files on Linux and WSL — sandboxed commands read a sentinel copy (the whole file, or just the spans captured by an extract regex) while the sandbox proxy substitutes the real value on egress; on macOS file masking falls back to deny

•Added warnings to claude plugin validate when a marketplace or plugin name would be rejected by Claude Desktop's managed marketplace sync

•Added a prompt-audit subcommand to the claude-api skill for auditing prompts and tool descriptions for patterns written for older models

Improved6 changes

•Improved tool search on Google Vertex AI: re-enabled for Claude 4.5-generation and newer models

•Improved auto mode: permission checks for parallel tool calls are now cache-efficient, and switching modes while a check is pending reliably prompts instead of applying the stale result

•Reduced prompt-cache costs for auto-mode permission checks by reusing the cached conversation prefix across decisions

•Improved Stats panel to count cache tokens in its token totals, with a breakdown by input, output, cache read, and cache write

•Improved /ultrareview error messages when a repo shares no history with its base: a checkout with no branches is now refused up front with advice to create one, and refusal hints no longer suggest git fetch --unshallow on clones that are already complete

•Improved Windows startup: process creation times are now read via a native kernel32 call instead of spawning PowerShell, so endpoint security tools that gate powershell.exe no longer prompt

Fixed17 changes

•Fixed a Bash tool permission-check bypass where zsh could execute hidden commands in [[ ]] regex conditionals; affected commands now prompt for permission

•Fixed PowerShell permission checks mishandling paths containing quote characters on Windows; such paths now prompt for approval

•Fixed the thinking toggle having no effect for the rest of a session that started with thinking off; disabling an MCP server mid-connect no longer silently reverts

•Fixed MCP servers from --mcp-config not being connected before the first turn in print mode (-p), which made the model emit tool calls as literal text

•Fixed @-mentioned files being silently dropped when pressing Esc to retract a prompt and resubmitting it

•Fixed a crash when preparing API requests for SDK MCP tools named after built-in object properties such as constructor

•Fixed WebSearch failing with a 400 error at effort xhigh/max when thinking is disabled

•Fixed sandboxed large uploads failing with TLS errors through the sandbox proxy

•Fixed Team and Enterprise spend-limit message incorrectly blaming the org's monthly limit instead of your individual spend limit

•Fixed Bedrock authentication with AWS SSO named profiles failing in desktop-managed sessions on Windows machines that set a stray HOME environment variable

•Fixed CLAUDE_CODE_RESUME_INTERRUPTED_TURN=0 not disabling interrupted-turn auto-resume; falsy values are now honored

•Fixed a rare wake-from-sleep race where two Claude Code processes could both refresh the same MCP connector or WIF OAuth token at once, forcing re-authentication

•Fixed renaming a session from Claude Code Desktop or claude.ai not updating the CLI's session name; session names from every rename surface are now sanitized

•Fixed plugin- and org-delivered skills named after terminal-only built-ins (e.g. /help, /feedback) being un-invocable in non-interactive sessions

•Fixed the "Plugins changed" notification lingering after plugins were reloaded instead of clearing

•Fixed Vim mode: the yank register now survives dialogs, history search, and the transcript view instead of being silently emptied

•Fixed Vim mode: undoing back to an empty prompt now arms the "press ← again" confirm before returning to the agent view

Changed11 changes

•Changed background sessions to commit and push to preserve work, open a draft PR only when the task calls for one, follow your CLAUDE.md git instructions, and always end by reporting where the work lives

•Changed /plugin install to refresh a stale marketplace catalog and retry before reporting a plugin not found

•Changed plugins installed from /plugin to activate immediately when safe, instead of always requiring /reload-plugins

•Changed plugins to accept "." as a skills path, and the root-level SKILL.md validation error now suggests using the plugin root

•Changed /status to show the session kind: interactive, or a background job that is attached or unattended

•Changed emoji autocomplete to accept common alternate shortcodes like :thumbsup:, :thumbsdown:, and :love:

•Changed sessions forked with /fork to create a new worktree of their own instead of working in the original session's checkout

•Changed Claude in Chrome to close the browser tabs it opens once it no longer needs them

•Changed fast mode to report on the stream when usage credits run out mid-session, instead of failing silently

•Changed Monitor: a watch that exits without producing any output now says so instead of reporting "stream ended"

•Changed the Gateway model field validation: non-string values are rejected with a 400 instead of being forwarded

v2.1.221 Claude Code Release Notes

Changes in Claude Code v2.1.221

Added4 changes

Improved6 changes

Fixed17 changes

Changed11 changes

Removed1 change

v2.1.221 Claude Code Release Notes

Changes in Claude Code v2.1.221

Added4 changes

Improved6 changes

Fixed17 changes

Changed11 changes

Removed1 change