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

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

## 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!