[BUG] Rate limiter not functioning correctly "API Error: Rate limit reached" when spawning more that one agent

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?

The rate limiter is broken. This is an issue across multiple accounts. "API Error: Rate limit reached" Claude can no longer spawn multiple agents without getting this error. We have been using claude code for a year and this just started today.

<img width="747" height="597" alt="Image" src="https://github.com/user-attachments/assets/d4f064d6-c2c9-4422-88a6-205fbdea6817" />

What Should Happen?

There bug needs to be fixed or the "new" parameters need to be revised so claude code is usable again

Error Messages/Logs

Steps to Reproduce

do any complex or multi-agent work or multiple sessions using the same account

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.81

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Xterm

Additional Information

We have replicated this on two different accounts. It seems that any heavy usage is triggering this bug