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Claude Code v2.1.316 Is Here: Opus 4.8 Fast Mode Ends on Nov 30

Claude Code Release ★★★★ View Markdown
#anthropic#ai#devops

Hi everyone, it's Shii-chan! A new Claude Code release, v2.1.316, is out, so let me walk you through the highlights!

Claude Code Release github.com

What was announced?

On the Claude Code Release page on GitHub, v2.1.316 was published. It includes new features, a deprecation notice, and lots of fixes.

The story so far

There was no way to turn off the ultrathink keyword, and subagents inherited the session's effort level. In the Claude apps gateway, budgets centered on each member's own limit.

What changes

Main additions:

  • CLAUDE_CODE_DISABLE_ULTRATHINK: turns off the ultrathink keyword
  • CLAUDE_CODE_SUBAGENT_EFFORT: sets the effort level subagents use when nothing else names one, instead of inheriting the session's
  • CLAUDE_CODE_DISABLE_LOOPED_CROSS_CERT_DROP: keeps system cross-certificates that certify each other in a loop, for servers whose private CA needs one
  • pooled_budget on the Claude apps gateway: one monthly budget shared by a group's members, on top of each member's own limit (set via the spend limits admin API)
  • managed.policy_mode: layered: every matching policy applies, each merged over the ones listed below it
  • guardrail.input_tagging: on Bedrock upstreams, wraps prompts in the input tags that an Amazon Bedrock guardrail's prompt attacks filter needs

Dive Deep

Fast mode for Opus 4.8 is deprecated

Fast mode for Opus 4.8 is deprecated as of October 30, 2026 and will be removed on November 30, 2026. After removal, fast mode requests return an error and do not fall back to standard Opus 4.8. To keep the speedup, migrate to Opus 5.5.

Changes and improvements

  • Auto mode: an autoMode.allow list without "$defaults" no longer removes the built-in rule on scheduled-task prompts
  • Server-managed settings for Team and Enterprise logins apply without an approval prompt, and a stored copy that doesn't verify is refused
  • VSCode: you can sign in to a gateway from the chat panel, and ultrathink runs at xhigh effort
  • SSL certificate errors now name likely causes, such as a missing intermediate certificate, and the fix for each

Notable fixes

  • Shell commands left running on macOS and Linux when Claude Code exits by itself
  • Bash aliases with line breaks and functions whose names start with a dash were garbled or lost
  • --restricted sessions uploaded files from outside the working directories when a Read allow rule covered them
  • The gateway didn't check every model a request names against availableModels and similar settings (blocked models now get a 400)
  • Network requests hung when a compressed response was cut off or corrupted

There are many more fixes for Vertex AI and Bedrock model fallback, Claude Tag, cloud sessions, the self-hosted runner, and Windows.

Wrap-up

  • Env vars now control ultrathink and subagent effort
  • The Claude apps gateway gains group-pooled budgets and layered policies
  • Opus 4.8 fast mode is removed on November 30, 2026, so move to Opus 5.5
  • Plenty of security and stability fixes

This is a must-read for admins running Claude Code across an organization and anyone using Opus 4.8 fast mode!

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