v2.1.229 Claude Code Release Notes

Aug 12, 2026Source: Anthropic changelog

Claude's Analysisby Sonnet 4.6

Broad stability pass: fixes crashes from narrow terminals, Windows UNC paths, and bad tool calls, plus streaming duplication and IDE UI freezes; VS Code adds session groups.

Changes

Total Changes (vs Average)

2.6×

Version Type

Patch

Release Focus

Bug Fixes

Day Since Prior Release

Release # This Month

#9 of 11

Bug Fix Ratio

56%

Post-Release Edits

—

Change Category

Ecosystem Impact

MCP has appeared in 6 of the last 10 releases; this one tightens OAuth redirect handling for strict authorization servers, continuing a steady cadence of MCP reliability work.

Key Themes

6Crash & Hang Fixes|4Provider & Gateway Reliability|5VS Code & Editor Workflow|5Self-Hosted Runner & Enterprise Hardening|1Breaking: Stricter Git Safety

May Help If You've Noticed

Claude Code crashed while working in a very narrow terminal window

Added4 changes

•Added server-supplied Claude Code hook support for self-hosted runner sessions, matching managed-environment behavior
•Added SSE keepalive pings to gateway streaming responses during long thinking pauses, preventing idle-timeout disconnects on Vertex and Bedrock upstreams
•Added plugin marketplace command sources: a local command (e.g. an IDE) prints the plugin directory, which is re-resolved each session and applied without a restart; mode: "link" uses it in place
•[VSCode] Added session groups in the sidebar — right-click to create, rename, or delete; Cmd/Ctrl- or Shift-click to move several sessions at once

Improved3 changes

•Improved workflow fan-outs to stagger same-prefix sibling agents so subsequent agents read the cached prompt prefix instead of re-paying it (CLAUDE_CODE_WORKFLOW_PREFIX_STAGGER_MS=0 disables)
•Improved "prompt is too long" errors to explain why automatic compaction could not recover instead of only suggesting /compact
•Improved sandbox: IPv6 literals in network domain lists are now bracketed ([::1]:443), and ambiguous spellings are enforced fail-closed and flagged by /doctor

Fixed18 changes

•Fixed long responses partly disappearing while streaming and being printed twice in the terminal
•Fixed a crash to the error screen (including on --resume of the affected session) when a tool call had a non-string glob, file_path, or command value
•Fixed a RangeError crash when a progress bar or markdown table rendered in a very narrow terminal window (could also crash claude --continue/--resume at startup)
•Fixed a crash on Windows when a tool call or message referenced a file by an extended-length (\\?\) or UNC path
•Fixed auto mode failing on every tool call for users who disable the attribution header via CLAUDE_CODE_ATTRIBUTION_HEADER (direct Anthropic API connections)
•Fixed /model rejecting Sonnet/Opus 1M for claude.ai subscribers using a custom ANTHROPIC_BASE_URL gateway
•Fixed MCP OAuth with strict authorization servers by using 127.0.0.1 instead of localhost in the redirect URI
•Fixed Remote Control clients showing a stuck working spinner after a slash command typed in the laptop terminal
•Fixed the Claude Code Review workflow generated by /install-github-app completing without posting its review on the pull request
•Fixed multi-second UI stalls after editing a file with thousands of IDE diagnostics while the IDE extension is connected
•Fixed one-shot claude plugin commands leaving a stray liveness file that could prevent cleanup of outdated plugin versions
•Fixed dynamic workflows inside CPU-limited containers using the host machine's core count instead of the container's CPU limit
•Fixed a file-watcher handle leak after atomic file replacements, and an uncaught error on Windows when the scheduled-tasks watcher failed on a network or virtual filesystem
•Fixed SDK and --input-format stream-json sessions getting a 400 API error when a whitespace-only message was submitted
•Fixed conversations whose messages alone exceed the API's 32 MB request limit retrying compaction when no images or documents can be stripped; they now fail once with a clear message
•Fixed OpenTelemetry export from Claude Desktop sessions being rejected by the Desktop-managed gateway when that gateway is also the telemetry endpoint
•Fixed self-hosted runner and other remote sessions exiting at startup when managed-mcp.json is deployed and the server delivers MCP servers; those servers are now skipped with a warning
•Fixed self-hosted runner repository preparation hanging on a Git Credential Manager prompt; git now fails fast when credentials are missing

Changed3 changes

•Updated /login to repeat the CLAUDE_CODE_OAUTH_TOKEN override warning after a successful login
•Changed /commit-push-pr so git/gh commands with dangerous flags (--force, --amend, --no-verify, etc.) are no longer auto-approved
•Changed self-hosted runner Windows startup to require an explicit --base-dir; there is no default checkout directory on Windows

Other4 changes

•Documented claude remote-control --continue for resuming the most recent Remote Control session
•ListAgents now marks disconnected Remote Control sessions as offline and labels your cloud sessions as cloud
•[VSCode] "Report a problem" and /bug now open the built-in feedback dialog instead of a retired survey link
•[VSCode] Made the /btw side-question panel resizable by dragging its boundary, in both side-docked and stacked layouts

Added4 changes

•Added server-supplied Claude Code hook support for self-hosted runner sessions, matching managed-environment behavior

•Added SSE keepalive pings to gateway streaming responses during long thinking pauses, preventing idle-timeout disconnects on Vertex and Bedrock upstreams

•Added plugin marketplace command sources: a local command (e.g. an IDE) prints the plugin directory, which is re-resolved each session and applied without a restart; mode: "link" uses it in place

•[VSCode] Added session groups in the sidebar — right-click to create, rename, or delete; Cmd/Ctrl- or Shift-click to move several sessions at once

Improved3 changes

•Improved workflow fan-outs to stagger same-prefix sibling agents so subsequent agents read the cached prompt prefix instead of re-paying it (CLAUDE_CODE_WORKFLOW_PREFIX_STAGGER_MS=0 disables)

•Improved "prompt is too long" errors to explain why automatic compaction could not recover instead of only suggesting /compact

•Improved sandbox: IPv6 literals in network domain lists are now bracketed ([::1]:443), and ambiguous spellings are enforced fail-closed and flagged by /doctor

Fixed18 changes

•Fixed long responses partly disappearing while streaming and being printed twice in the terminal

•Fixed a crash to the error screen (including on --resume of the affected session) when a tool call had a non-string glob, file_path, or command value

•Fixed a RangeError crash when a progress bar or markdown table rendered in a very narrow terminal window (could also crash claude --continue/--resume at startup)

•Fixed a crash on Windows when a tool call or message referenced a file by an extended-length (\\?\) or UNC path

•Fixed auto mode failing on every tool call for users who disable the attribution header via CLAUDE_CODE_ATTRIBUTION_HEADER (direct Anthropic API connections)

•Fixed /model rejecting Sonnet/Opus 1M for claude.ai subscribers using a custom ANTHROPIC_BASE_URL gateway

•Fixed MCP OAuth with strict authorization servers by using 127.0.0.1 instead of localhost in the redirect URI

•Fixed Remote Control clients showing a stuck working spinner after a slash command typed in the laptop terminal

•Fixed the Claude Code Review workflow generated by /install-github-app completing without posting its review on the pull request

•Fixed multi-second UI stalls after editing a file with thousands of IDE diagnostics while the IDE extension is connected

•Fixed one-shot claude plugin commands leaving a stray liveness file that could prevent cleanup of outdated plugin versions

•Fixed dynamic workflows inside CPU-limited containers using the host machine's core count instead of the container's CPU limit

•Fixed a file-watcher handle leak after atomic file replacements, and an uncaught error on Windows when the scheduled-tasks watcher failed on a network or virtual filesystem

•Fixed SDK and --input-format stream-json sessions getting a 400 API error when a whitespace-only message was submitted

•Fixed conversations whose messages alone exceed the API's 32 MB request limit retrying compaction when no images or documents can be stripped; they now fail once with a clear message

•Fixed OpenTelemetry export from Claude Desktop sessions being rejected by the Desktop-managed gateway when that gateway is also the telemetry endpoint

•Fixed self-hosted runner and other remote sessions exiting at startup when managed-mcp.json is deployed and the server delivers MCP servers; those servers are now skipped with a warning

•Fixed self-hosted runner repository preparation hanging on a Git Credential Manager prompt; git now fails fast when credentials are missing

Changed3 changes

•Updated /login to repeat the CLAUDE_CODE_OAUTH_TOKEN override warning after a successful login

•Changed /commit-push-pr so git/gh commands with dangerous flags (--force, --amend, --no-verify, etc.) are no longer auto-approved

•Changed self-hosted runner Windows startup to require an explicit --base-dir; there is no default checkout directory on Windows

Other4 changes

•Documented claude remote-control --continue for resuming the most recent Remote Control session

•ListAgents now marks disconnected Remote Control sessions as offline and labels your cloud sessions as cloud

•[VSCode] "Report a problem" and /bug now open the built-in feedback dialog instead of a retired survey link

•[VSCode] Made the /btw side-question panel resizable by dragging its boundary, in both side-docked and stacked layouts

v2.1.229 Claude Code Release Notes

Changes in Claude Code v2.1.229

Added4 changes

Improved3 changes

Fixed18 changes

Changed3 changes

Other4 changes

v2.1.229 Claude Code Release Notes

Changes in Claude Code v2.1.229

Added4 changes

Improved3 changes

Fixed18 changes

Changed3 changes

Other4 changes