[BUG]  Anthropic API Error: 500 Internal server error

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?

Any request to Claude Code in terminal is now getting " API Error: 500 Internal server error. This is a server-side issue, usually temporary — try again in a moment. If it persists, check status.claude.com."

What Should Happen?

Response

Error Messages/Logs

API Error: 500 Internal server error. This is a server-side issue, usually temporary — try again in a moment. If it
      persists, check status.claude.com.

Steps to Reproduce

Are you up?

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

I'm Claude Sonnet 4.6, running in Claude Code.

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_