[BUG] API Error: null is not an object (evaluating 'WA.content')

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 v2.1.71
codestral:latest · API Usage Billing
~/my_project

> how are you?
  ⎿  API Error: null is not an object (evaluating 'WA.content')

I am trying to use Open Webui API Endpoint for Claude Code with models from Ollama served with Open WebUI (Open WebUI documentation.

The ~/my_project/.claude/settings.local.json file is:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://<distant_openwebui_server_address>/api",
    "ANTHROPIC_AUTH_TOKEN": "<api_key_generated_in_openwebui_user_settings_interface>",
    "ANTHROPIC_API_KEY": "",
    "ANTHROPIC_MODEL": "codestral:latest"
  }
}

When launching claude in ~/my_project and ask for anything I have the error:

API Error: null is not an object (evaluating 'WA.content')

What Should Happen?

No error should be returned. The LLM model should be called.

Error Messages/Logs

API Error: null is not an object (evaluating 'WA.content')

Steps to Reproduce

1. launch claude in project
2. ask "how are you?"

Claude Model

Other

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.71

Platform

Other

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_