Claude Code v2.1.316：弃用 Opus 4.8 fast mode

What's changed

• Added CLAUDE_CODE_DISABLE_ULTRATHINK, which turns the ultrathink keyword off
• Added pooled group budgets to the Claude apps gateway: one monthly budget that a group's members share, on top of each member's own limit, set with pooled_budget on the spend limits admin API
• Added CLAUDE_CODE_DISABLE_LOOPED_CROSS_CERT_DROP to keep system cross-certificates that certify each other in a loop, for servers whose private CA needs one
• Added CLAUDE_CODE_SUBAGENT_EFFORT to set the effort level subagents run at when nothing else names one, instead of inheriting the session's
• Added managed.policy_mode: layered to the Claude apps gateway: every policy that matches a developer applies, each merged over the ones listed below it, not only the first
• Added guardrail.input_tagging on Claude apps gateway Bedrock upstreams, which wraps prompts in the input tags that an Amazon Bedrock guardrail's prompt attacks filter needs; all_messages_and_system also tags the system prompt
• Deprecated fast mode for Opus 4.8 as of October 30, 2026; it will be removed on November 30, 2026. After removal, fast mode requests on Opus 4.8 return an error and do not fall back to standard Opus 4.8. Migrate to Opus 5.5 to keep the speedup
• Fixed shell commands being left running on macOS and Linux when Claude Code exits by itself, for example when credentials are refused or a cloud session is archived
• Fixed bash aliases with line breaks in their value (except in Git Bash), and functions whose names start with a dash, being garbled or lost in the Bash tool's shell
• Fixed bash scripts started from the Bash tool stopping after their first command when SHELLOPTS is exported
• Fixed PowerShell hooks not blocking on exit code 2 when the command begins with a type cast, param, using or an attribute
• Fixed some network requests hanging when a compressed response was cut off or corrupted
• Fixed sonnet, opus and haiku on Vertex AI and Amazon Bedrock showing an error mid-session instead of switching to an older model when the newest is not yet available to the account or region
• Fixed the Claude apps gateway not checking every model a request names against availableModels, deniedModels and models; a request that names a blocked model now gets a 400 naming the field
• Fixed claude auth login refusing to run where managed settings require a Claude apps gateway; in a terminal it now shows the gateway sign-in
• Fixed --restricted sessions uploading files from outside the working directories when a Read allow rule covered them
• Fixed prompts containing invisible characters needing a second Enter to send; plain prompts now send cleaned on the first Enter, and commands still wait for review
• Fixed sub-agents that inherited a parent sub-agent's model moving to the main model when a background job or message woke them
• Fixed a managed autoMode.allow list without "$defaults" getting the built-in exceptions back from a host app's --settings, a first rule added in /permissions, or /auto-mode-setup
• Fixed cloud sessions and cloud scheduled tasks not being marked as failed when auto mode stopped a turn because the server returned no safety verdict
• Fixed claude -p text output sometimes not saying why auto mode stopped a turn when a background agent was still running
• Fixed CLAUDE_CODE_AUTO_MODE_SERVER=1 being ignored in sessions started by a host application (such as Claude Desktop) behind a proxy or LLM gateway with experimental betas turned off
• Fixed plugin MCP headersHelper scripts receiving a corrupted CLAUDE_PLUGIN_ROOT and server URL when a credential-named environment variable was set to a switch value such as 1
• Fixed the SDK register_repo_root control request not loading the CLAUDE.md of a directory outside the working directory (with CLAUDE_CODE_ADDITIONAL_DIRECTORIES_CLAUDE_MD=1)
• Fixed the Artifact tool showing ? for artifact database access rules at the self level, and not quoting those rules back when it refuses a republish that would drop them
• Fixed /model <id> not warning when the model isn't recognized by this version and auto-compact will assume a 200K context window
• Fixed the "hold space to speak" hint using up its three showings in one session, and showing an empty key when push-to-talk is unbound
• Fixed Grep and Glob never returning when the search process is killed at the timeout but does not exit, seen on Windows
• Fixed a rare case where resuming a conversation did not restore its plan, when /clear or /resume had been run while part of that conversation was still being saved
• Fixed first-run setup dropping words from the security notes and the terminal-setup explanation in narrow terminals
• Fixed the Enterprise survey card taking a typed 1 or 0 after a short pause; a typed answer now needs Enter
• Self-hosted runner: Fixed a message sent while Claude was working being answered after a Stop, once the session's process had been replaced
• Self-hosted runner: Fixed an MCP server's on/off switch sometimes being lost when a session moved to a new machine
• Windows: Fixed the Bash tool losing your aliases and functions in Git Bash when the rc file sets errexit and pipefail and only winpty aliases, or none, are defined
• Improved /code-review started from the Code tab in Claude Desktop or on the web: cloud and claude remote-control sessions now show the findings card, not a plain-text list
• Improved /diff on large repositories: each refresh usually runs one fewer full-repository git command, and refreshes are spaced out when git is slow
• Improved the messages shown when /ultrareview, a cloud session or a cloud agent finds no GitHub remote: they now say to create a repository at https://github.com/new, and /ultrareview no longer suggests a gh command that gh rejects
• Improved SSL certificate errors to name the likely causes, among them a server that leaves out an intermediate certificate, and the fix for each
• Changed auto mode so that an autoMode.allow list without "$defaults" no longer removes the built-in rule on scheduled-task prompts
• Changed server-managed settings for Team and Enterprise logins: settings fetched from Anthropic's API now apply without an approval prompt, and a stored copy that doesn't verify is refused
• [VSCode] Added sign-in to a Claude apps gateway from the chat panel, with no terminal needed
• [VSCode] Changed ultrathink to run its turn at xhigh effort and show in a rainbow in the chat box, as in the terminal
• [VSCode] Fixed the missing Effort slider, Ultracode switch and model name when the model setting has the [1m] tag, such as opus[1m]
• [VSCode] Fixed saved /btw side-question history being deleted too early while a settings file has errors
• [VSCode] Fixed a conversation coming back in Auto mode after a reload or restart when its plan was approved with "Yes, and manually approve edits"
• [Cloud sessions] Added a form card to cloud sessions, so you can fill in or decline a form an MCP server asks for instead of the request being canceled without you seeing it
• [Cloud sessions] Added a "Catching up…" line that shows while a cloud or Remote Control session you switch back to is still bringing its messages up to date
• [Cloud sessions] Changed network secrets so Enterprise members can add and delete them on their own cloud environments, instead of only viewing them
• [Cloud sessions] Improved the Changes pane for cloud sessions: the note about what the list leaves out is now a badge beside the branch name, not a row above the diff
• [Cloud sessions] Fixed file search in a cloud session's Files pane showing folders as ../.. paths after Claude changed directory; results now show their path from the project's root
• [Claude Tag] Fixed Claude refusing to edit or append to a canvas it made in a Slack channel, from that channel, once the canvas was also shared to another channel or a DM