[BUG] Repeated 500 errors

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?

Repeated 500 errors.

<img width="1194" height="253" alt="Image" src="https://github.com/user-attachments/assets/1763acba-9941-4678-a24a-92ceb3386cf6" />

<img width="1119" height="264" alt="Image" src="https://github.com/user-attachments/assets/00a13bc2-f842-4dcd-8697-37ab327b1b28" />

What Should Happen?

Not 500 errors

Error Messages/Logs

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011Ca21fXRvMcQuopaNwHZDf"}

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011Ca21dQ37iDb8hsporJtUX"}

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011Ca21bLqL1uPGsD8pXidzc"}

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011Ca21hVDmkAanhtRPgaSY5"}

Steps to Reproduce

1. Ask Claude Code anything using the Opus 4.6 model.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.103

Claude Code Version

2.1.104

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_