Claude Code 2.1.314–2.1.316: block writes outside the working folder, default subagent effort, idle compaction
What is it?
Claude Code is Anthropic's terminal coding agent. Version 2.1.314 adds the permissions.blockWritesOutsideWorkingDirectories setting. With it on, the Write, Edit and NotebookEdit tools refuse paths outside the working folders in every permission mode. The same version brings idle compaction to VS Code and the Code tab in Claude Desktop: a conversation over 200K tokens that sits idle gets summarized ahead of time. Version 2.1.316 adds CLAUDE_CODE_SUBAGENT_EFFORT, which sets the default effort level for subagents (helper agents that take pieces of a task), and CLAUDE_CODE_DISABLE_ULTRATHINK, which turns off the ultrathink keyword. To update:
claude updateWhy does it matter?
The scariest part of leaving an agent in auto mode for hours is that it might touch your home folder or config files, and now one setting keeps its writes inside the working folder. A separate subagent effort level lets you run the main session high and the helpers doing chores low, which saves money. Org admins also get new Claude apps gateway controls, such as shared group budgets and layered policies.
Maturity
GAWe rated it GA because it's a shipped CLI release. The same release says Opus 4.8 fast mode goes away on Nov 30, so anyone using it should move to Opus 5.5.
How to track it
- Release notes: watch the claude-code GitHub releases to see whether write blocking extends to reads and Bash.
- Fast mode retirement: check the Claude Platform release notes in case the Nov 30 removal date for Opus 4.8 fast mode changes.