[BUG]

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?

Claude Code returns 500 Internal Server Error on all API requests. Affects all models (Haiku, Sonnet, Opus) on both CLI and VS Code extension simultaneously. Claude.ai web interface works normally during this time.

What Should Happen?

API requests should complete successfully and return model responses.

Error Messages/Logs

2026-02-03T15:44:40.412Z [ERROR] API error (attempt 1/11): 500 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmPnWqxaBgx1fPsfsDJg"}
2026-02-03T15:44:40.412Z [ERROR] Error in non-streaming fallback: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmPnWqxaBgx1fPsfsDJg"}
2026-02-03T15:44:40.413Z [ERROR] Error: Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CXmPnWqxaBgx1fPsfsDJg"}

Steps to Reproduce

1. Open Claude Code (CLI or VS Code extension)
2. Connect to IDE with /ide
3. Send any message (e.g., "hello" or any file request)
4. Receive 500 Internal Server Error immediately

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

unknown

Claude Code Version

2.1.29

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Request IDs for tracking:

• req_011CXmPnWqxaBgx1fPsfsDJg
• req_011CXmPmkqJQvuvgiEtE4GCH
• req_011CXmPmmzFjzFuFBaJmsiSy
• req_011CXmPmoM7ZSm7tp47u3tDj

Timestamp: 2026-02-03 15:44 UTC

Note: status.claude.com shows "All Systems Operational" but the API is clearly having issues.