Feature request: Support localization/language setting for permission prompt UI dialogs

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?

Currently, the tool permission dialogs (e.g., "Make this edit to...?", "Yes / Yes, allow access / No")
are hardcoded in English and cannot be changed via CLAUDE.md or any config setting.

It would be great to have a way to set the UI language for these dialogs, either:

• Via a claude config setting (e.g., language: ja)
• Or by following the OS locale setting automatically

This would improve usability for non-English speakers.

What Should Happen?

Currently, the tool permission dialogs (e.g., "Make this edit to...?", "Yes / Yes, allow access / No")
are hardcoded in English and cannot be changed via CLAUDE.md or any config setting.

It would be great to have a way to set the UI language for these dialogs, either:

• Via a claude config setting (e.g., language: ja)
• Or by following the OS locale setting automatically

This would improve usability for non-English speakers.

Error Messages/Logs

Steps to Reproduce

Currently, the tool permission dialogs (e.g., "Make this edit to...?", "Yes / Yes, allow access / No")
are hardcoded in English and cannot be changed via CLAUDE.md or any config setting.

It would be great to have a way to set the UI language for these dialogs, either:

• Via a claude config setting (e.g., language: ja)
• Or by following the OS locale setting automatically

This would improve usability for non-English speakers.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.177

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_