[BUG] API Error 500 - Internal server error on all prompts (v2.1.77, native install)

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?

Bug Description
Persistent API 500 Internal Server Error on every prompt. Claude Code is completely unusable.

Environment

• Claude Code version: 2.1.77
• Installation method: Native binary (curl installer)
• Platform: [your OS here]

Error Message
API Error: 500 {"type":"error","error":{"type":"api_error","message":"Internal server error"},"request_id":"req_011CZ9DpXsQzBJgV17veYvXV"}

Request IDs

• req_011CZ9DpXsQzBJgV17veYvXV
• req_011CZ9ENiDuVGwqffc8Z2TgD

Behavior

• Error occurs on all prompts
• Starting a new session does not fix it
• /clear does not fix it
• Already on latest version

What Should Happen?

Claude Code should respond normally to prompts.

Error Messages/Logs

Steps to Reproduce

I am just asking it questions.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.77 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Non-interactive/CI environment

Additional Information

_No response_