[BUG] CLAUDE_CODE_USE_POWERSHELL_TOOL causing model 503s when using with Bedrock

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?

When I have CLAUDE_CODE_USE_POWERSHELL_TOOL set to 1 and I try to use claude code with bedrock I get

● API Error: 503 Bedrock is unable to process your request. This is a server-side issue, usually temporary — try

again in a moment. If it persists, check your Amazon Bedrock service status

However when I run without it set it works fine.

What Should Happen?

I should be able to run with CLAUDE_CODE_USE_POWERSHELL_TOOL on while using Bedrock

Error Messages/Logs

 ● API Error: 503 Bedrock is unable to process your request. This is a server-side issue, usually temporary — try
  again in a moment. If it persists, check your Amazon Bedrock service status

Steps to Reproduce

1. Setup Claude Code to use Bedrock (I am using 4.8)
2. Set CLAUDE_CODE_USE_POWERSHELL_TOOL to 1
3. Start Claude code and ask if it is available, notice it fails with 503
4. Set CLAUDE_CODE_USE_POWERSHELL_TOOL to 0
5. Start Claude code and ask if it is available, notice it works

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.1.186

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_