v2.1.84 Claude Code Release Notes

Mar 26, 2026

Claude's Analysisby Sonnet 4.6

New env vars override Opus/Sonnet/Haiku capability detection for Bedrock, Vertex & Foundry; PowerShell lands on Windows; 14 fixes span input hangs, voice leaks, and MCP cache leaks

Changes

Total Changes (vs Average)

5.4×

Version Type

Patch

Release Focus

Mixed

Day Since Prior Release

Release # This Month

#17 of 17

Bug Fix Ratio

33%

Post-Release Edits

—

Change Category

Ecosystem Impact

Chrome makes its first tracked appearance while Windows has featured in 8 of the last 10 releases — sustained cross-platform investment. MCP items appear in 7 of the last 10 releases, cementing it as an ongoing infrastructure and reliability priority.

Key Themes

May Help If You've Noticed

Voice dictation inserts stray characters or your transcript lands in the wrong spot in the text input

Added8 changes

•Added PowerShell tool for Windows as an opt-in preview. Learn more at https://code.claude.com/docs/en/tools-reference#powershell-tool
•Added ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_SUPPORTS env vars to override effort/thinking capability detection for pinned default models for 3p (Bedrock, Vertex, Foundry), and _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 in the response JSON
•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, reducing unnecessary token re-caching on stale sessions

Improved5 changes

•Improved detection for dangerous removals of Windows drive roots (C:\, C:\Windows, etc.)
•Improved interactive startup by ~30ms by running setup() in parallel with slash command and agent loading
•Improved startup for claude "prompt" with MCP servers — the REPL now renders immediately instead of blocking until all servers connect
•Improved Remote Control to show a specific reason when blocked instead of a generic "not yet enabled" message
•Improved p90 prompt cache rate

Fixed13 changes

•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, so repeated Ctrl+U now clears across lines
•Fixed null-unbinding a default chord binding (e.g. "ctrl+x ctrl+k": null) still entering chord-wait mode instead of freeing the prefix key
•Fixed mouse events inserting literal "mouse" text into transcript search input
•Fixed workflow subagents failing with API 400 when the outer session uses --json-schema and the subagent also specifies a schema
•Fixed missing background color behind certain emoji in user message bubbles on some terminals
•Fixed the "allow Claude to edit its own settings for this session" permission option not sticking for users with Edit(.claude) allow rules
•Fixed a hang when generating attachment snippets for large edited files
•Fixed MCP tool/resource cache leak on server reconnect
•Fixed a startup performance issue where partial clone repositories (Scalar/GVFS) triggered mass blob downloads
•Fixed native terminal cursor not tracking the text input caret, so IME composition (CJK input) now renders inline and screen readers can follow the input position
•Fixed spurious "Not logged in" errors on macOS caused by transient keychain read failures
•Fixed cold-start race where core tools could be deferred without their bypass active, causing Edit/Write to fail with InputValidationError on typed parameters

Removed2 changes

•Fixed voice push-to-talk: holding the voice key no longer leaks characters into the text input, and transcripts now insert at the correct position
•Changed issue/PR references to only become clickable links when written as owner/repo#123 — bare #123 is no longer auto-linked

Other12 changes

•Deep links (claude-cli://) now open in your preferred terminal instead of whichever terminal happens to be first in the detection list
•Rules and skills paths: frontmatter now accepts a YAML list of globs
•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
•Reduced scroll-to-top resets in long sessions by making the message window immune to compaction and grouping changes
•Reduced terminal flickering when animated tool progress scrolls above the viewport
•Slash commands unavailable for the current auth setup (/voice, /mobile, /chrome, /upgrade, etc.) are now hidden instead of shown
•[VSCode] Added rate limit warning banner with usage percentage and reset time
•Stats screenshot (Ctrl+S in /stats) now works in all builds and is 16× faster

Added8 changes

•Added PowerShell tool for Windows as an opt-in preview. Learn more at https://code.claude.com/docs/en/tools-reference#powershell-tool

•Added ANTHROPIC_DEFAULT_{OPUS,SONNET,HAIKU}_MODEL_SUPPORTS env vars to override effort/thinking capability detection for pinned default models for 3p (Bedrock, Vertex, Foundry), and _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 in the response JSON

•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, reducing unnecessary token re-caching on stale sessions

Improved5 changes

•Improved detection for dangerous removals of Windows drive roots (C:\, C:\Windows, etc.)

•Improved interactive startup by ~30ms by running setup() in parallel with slash command and agent loading

•Improved startup for claude "prompt" with MCP servers — the REPL now renders immediately instead of blocking until all servers connect

•Improved Remote Control to show a specific reason when blocked instead of a generic "not yet enabled" message

•Improved p90 prompt cache rate

Fixed13 changes

•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, so repeated Ctrl+U now clears across lines

•Fixed null-unbinding a default chord binding (e.g. "ctrl+x ctrl+k": null) still entering chord-wait mode instead of freeing the prefix key

•Fixed mouse events inserting literal "mouse" text into transcript search input

•Fixed workflow subagents failing with API 400 when the outer session uses --json-schema and the subagent also specifies a schema

•Fixed missing background color behind certain emoji in user message bubbles on some terminals

•Fixed the "allow Claude to edit its own settings for this session" permission option not sticking for users with Edit(.claude) allow rules

•Fixed a hang when generating attachment snippets for large edited files

•Fixed MCP tool/resource cache leak on server reconnect

•Fixed a startup performance issue where partial clone repositories (Scalar/GVFS) triggered mass blob downloads

•Fixed native terminal cursor not tracking the text input caret, so IME composition (CJK input) now renders inline and screen readers can follow the input position

•Fixed spurious "Not logged in" errors on macOS caused by transient keychain read failures

•Fixed cold-start race where core tools could be deferred without their bypass active, causing Edit/Write to fail with InputValidationError on typed parameters

Other12 changes

•Deep links (claude-cli://) now open in your preferred terminal instead of whichever terminal happens to be first in the detection list

•Rules and skills paths: frontmatter now accepts a YAML list of globs

•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

•Reduced scroll-to-top resets in long sessions by making the message window immune to compaction and grouping changes

•Reduced terminal flickering when animated tool progress scrolls above the viewport

•Slash commands unavailable for the current auth setup (/voice, /mobile, /chrome, /upgrade, etc.) are now hidden instead of shown

•[VSCode] Added rate limit warning banner with usage percentage and reset time

•Stats screenshot (Ctrl+S in /stats) now works in all builds and is 16× faster

v2.1.84 Claude Code Release Notes

Changes in Claude Code v2.1.84

Added8 changes

Improved5 changes

Fixed13 changes

Removed2 changes

Other12 changes

v2.1.84 Claude Code Release Notes

Changes in Claude Code v2.1.84

Added8 changes

Improved5 changes

Fixed13 changes

Removed2 changes

Other12 changes