[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?

I'm getting "OAuth error: Request failed with status code 400" when trying to log in.

My Claude Code version: [paste the number from claude --version here]
Login method I selected: [1, 2, or 3]

What Should Happen?

I'm having to many problems getting access to my terminal I have pasted the correct URL im still not getting access to the terminal can please assist me with this problem jb2JPhJ7Jm5CjAVuJmpFSe4cilovyBPNuHVf3dghfZ9N6vv1#6NPbzUIkcu2rvjZBhVoPrpIIF2zuZ8fGLz6Pi4nVM2w

Error Messages/Logs

Steps to Reproduce

1. Run claude --version to check version
2. Run /login in Claude Code
3. Select login method 1 (or 2 or 3 - whichever you chose)
4. Copy the authorization URL and paste it in browser
5. Sign in and copy the authorization code
6. Paste the code back into Claude Code when prompted
7. Receive "OAuth error: Request failed with status code 400"
8. Press Enter to retry - same error appears

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

claude --version

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

<img width="1889" height="1000" alt="Image" src="https://github.com/user-attachments/assets/23a46a5f-ba1a-4e9b-ba69-a4de6d092ad0" />

<img width="1889" height="1000" alt="Image" src="https://github.com/user-attachments/assets/b4b43c22-6520-4490-94eb-62dc7075f4fa" />