[BUG] CPU usage 100% while idle - extra details and work around found

Preflight Checklist

• [ ] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Symptom pattern — input render frozen + 99% CPU, both released by forcing a redraw (terminal resize / file-browser toggle) — points to a Claude Code rendering or event-loop deadlock, not a model-side issue. The fact that the CPU dropped with the redraw (not just the typing unblock) suggests both were stuck on the same loop.

Worth reporting at https://github.com/anthropics/claude-code/issues. The details you already have are the load-bearing ones:

• Two instances simultaneously affected
• ~90 min of pegged CPU
• VS Code Claude and terminal both — so not extension-specific
• Workaround: force a redraw (resize / file-browser toggle) - discovered this solves the issue.

What Should Happen?

It should allow typing into text area but its blocked until "re-drawing" interface

Error Messages/Logs

Steps to Reproduce

Just leave idle

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.167 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_