[BUG] /plugin doesn't work in Claude Code

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 type /plugin in Claude Code, it says "/plugin isn't available in this environment."

What Should Happen?

The /plugin command should work so I can install the create-mcp-app skill.

Error Messages/Logs

/plugin isn't available in this environment

Steps to Reproduce

Open Claude Code desktop app on Mac
Type /plugin
Error appears: "/plugin isn't available in this environment."

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

v2.1.131

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

<img width="1342" height="767" alt="Image" src="https://github.com/user-attachments/assets/5c74b076-fd8c-4cdb-83d7-0b85c3d1302f" />