[BUG] Plugin marketplace sync fails on Claude Code web despite working in desktop app

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?

Adding a personal plugin marketplace repository fails to sync in the web version of Claude Code (claude.ai/code), even though the same repository is accessible and syncs correctly in the Claude Code desktop app, and my GitHub account is connected in web settings.

What Should Happen?

The marketplace syncs successfully and lists its plugins (in my case three: Alf, Diane, Louis), matching what already works in the desktop app for the same repo.

Error Messages/Logs

Steps to Reproduce

1. On claude.ai/code, go to Customize → Plugins → Directory → Personal.
2. Click Add marketplace.
3. Enter the repo as owner/repo — in my case Blake-Carroll25/circa-systems-plugins.
4. Leave Sync automatically enabled and click Sync.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Current web session environment has Claude Code CLI version 2.1.223 installed.

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

<img width="960" height="1044" alt="Image" src="https://github.com/user-attachments/assets/ca9d78f2-e376-42b5-9564-d6ed0baff6f0" />
<img width="960" height="1044" alt="Image" src="https://github.com/user-attachments/assets/357f1b6e-fbf8-475f-b3b2-eabb02f3b131" />
<img width="960" height="1044" alt="Image" src="https://github.com/user-attachments/assets/b1cfe1a0-b3bb-4084-9a34-8fdcab0b3fc4" />
<img width="1128" height="716" alt="Image" src="https://github.com/user-attachments/assets/8f9ca498-404f-45a6-83db-f960d123b11c" />