[BUG] Native-Build client - massive performance issues

Preflight Checklist

• [x] 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?

Since updating to the native build version of claude-code, i have massive input delay and performance impact while typing.

claude uses 100% of single CPU core while typing, leading to massive lags.

This behaviour can be observed in wezterm and Konsole.

As soon as the claude-code cli tries to update anything in the window, those spikes can be observed.

What Should Happen?

No input lag, no CPU spikes.

Error Messages/Logs

Steps to Reproduce

1. open claude-code
2. do something with it

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.22 (Claude Code)

Platform

Anthropic API

Operating System

Other Linux

Terminal/Shell

Other

Additional Information

Displaying text in a terminal is a standard task. The fact that this has such a massive overhead and nobody catches this in QA is a bad sign for antropic.