[BUG] Installation Sign-in "Missing redirect_uri parameter"

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?

Unable to sign in

<img width="954" height="568" alt="Image" src="https://github.com/user-attachments/assets/9f5cca53-ddd7-41dc-933e-fdbbc4a9dbcc" />

<img width="749" height="674" alt="Image" src="https://github.com/user-attachments/assets/27517eeb-9d2e-4b04-9c22-275fd347fdc1" />

What Should Happen?

I should be able to login to Claude Code via terminal.

Error Messages/Logs

Steps to Reproduce

1. curl -fsSL https://claude.ai/install.sh | bash
2. Claude
3. Continue through until you reach choosing which option to sign-in
4. Go with option 1

<img width="749" height="674" alt="Image" src="https://github.com/user-attachments/assets/c5f1fb98-5385-49c9-b703-3218f7178cad" />

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.215 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_