[Bug] Anthropic API Error: Internal Server Error (500) - Mass Outage

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?

Getting API Error 500 on every request. All conversations fail simultaneously — clearly a server-side outage.

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

Restarting terminal does not fix the issue.

What Should Happen?

Claude Code should respond normally to prompts without server errors.

Error Messages/Logs

API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9DdvuT5JmT8jbqhBig8"}
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9DkCB8X6K384cQnfpJM"}
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9EBZsZC3jQfpAQ4FFm6"}

Steps to Reproduce

1. Open Claude Code
2. Send any prompt
3. Immediately receive 500 Internal Server Error
4. All terminals and conversations affected simultaneously

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.77 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

<img width="2306" height="136" alt="Image" src="https://github.com/user-attachments/assets/3f94badc-0682-4c1c-aa60-ae2f00a622d7" />