[BUG] claude.ai/code API Error: 400

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?

<img width="814" height="878" alt="Image" src="https://github.com/user-attachments/assets/4b4396fd-f2dd-4808-8704-90b5b38c9dda" />

What Should Happen?

-

Error Messages/Logs

-

Steps to Reproduce

-

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

-

Claude Code Version

-

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_