Original Reddit post

Claude Code 2.1.316 landed on Oct 31. It is mostly fixes (34 of them), but a few items change how you set things up:

  • CLAUDE_CODE_SUBAGENT_EFFORT: sets the effort level subagents run at when nothing else names one, instead of inheriting the session’s. So you can run the main session at high and have subagents do grunt work at low. Someone tested it: with the variable set to low, the subagent ran at low while the main session stayed at high.
  • CLAUDE_CODE_DISABLE_ULTRATHINK: turns the ultrathink keyword off. Useful if the word shows up in your prompts by accident and keeps bumping effort to xhigh.
  • Fast mode for Opus 4.8 is deprecated as of Oct 30 and will be removed on Nov 30, 2026. After that, fast mode requests on Opus 4.8 return an error with no fallback to standard Opus 4.8. The changelog says migrate to Opus 5.5 to keep the speedup.
  • Team and Enterprise logins: server-managed settings now apply without an approval prompt. If your admin pushes settings, you will not see the “accept?” step anymore.
  • Security fix: --restricted sessions could upload files from outside the working directories when a Read allow rule covered them. Fixed now, worth updating for this alone.
  • Fix: shell commands were left running on macOS and Linux when Claude Code exited by itself (expired credentials, archived cloud session). Also fixed.
  • VS Code: ultrathink now runs the turn at xhigh and shows the rainbow, same as the terminal. Also from 2.1.314 earlier this week: permissions.blockWritesOutsideWorkingDirectories (Write/Edit refuse paths outside the working dirs in every permission mode), and idle compaction came to VS Code and the Desktop app’s Code tab (a 200K+ token conversation left idle gets summarized). The subagent effort variable is the one I want to try first. My subagents mostly grep and read files, they do not need high effort. If you use subagents a lot: what effort level are you going to give them, and does low actually hurt on search-type tasks? Source: https://github.com/anthropics/claude-code/releases/tag/v2.1.316 submitted by /u/emarkosov

Originally posted by u/emarkosov on r/ClaudeCode