[BUG] Unknown slash command: plugin

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?

/plugin marketplace add anthropics/claude-code

> Unknown slash command: plugin 

> /doctor 

 Diagnostics
 └ Currently running: native (2.0.12)
 └ Path: /home/coder/.local/bin/claude
 └ Invoked: /home/coder/.local/share/claude/versions/2.0.12
 └ Config install method: native
 └ Auto-updates enabled: default (true)
 └ Search: OK (bundled)

What Should Happen?

Claude should add marketplace successfully without errors.

Error Messages/Logs

> Unknown slash command: plugin

Steps to Reproduce

1. run claude
2. /plugin marketplace add anthropics/claude-code

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.0.12 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

IntelliJ IDEA terminal

Additional Information

Diagnostics
└ Currently running: native (2.0.12)
└ Path: /home/coder/.local/bin/claude
└ Invoked: /home/coder/.local/share/claude/versions/2.0.12
└ Config install method: native
└ Auto-updates enabled: default (true)
└ Search: OK (bundled)