Plugin marketplace fails to load - Invalid schema errors on plugin source fields

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 running /plugin or /plugin Discover, the plugin marketplace fails to load with schema validation errors.

Error message:
Failed to load all marketplaces. Errors: claude-plugins-official: Invalid schema: plugins.3.source: Invalid input, plugins.6.source: Invalid input,
plugins.14.source: Invalid input, plugins.36.source: Invalid input, plugins.40.source: Invalid input, plugins.57.source: Invalid input,
plugins.66.source: Invalid input, plugins.72.source: Invalid input, plugins.75.source: Invalid input, plugins.95.source: Invalid input,
plugins.98.source: Invalid input, plugins.108.source: Invalid input, plugins.119.source: Invalid input, plugins.127.source: Invalid input,
plugins.128.source: Invalid input, plugins.133.source: Invalid input

Steps to reproduce:

1. Run claude to start Claude Code
2. Run /login and authenticate successfully
3. Run /plugin or /plugin Discover

Expected behavior:
Plugin marketplace loads and displays available plugins.

Actual behavior:
Marketplace fails to load due to schema validation errors on multiple plugins' source fields.

Environment:

• OS: macOS (Darwin 25.2.0)
• Claude Code version: [run claude --version and add here]

Notes:
The error affects 16 plugins at various indices, suggesting the marketplace data contains source field values that don't match the expected schema
format.

What Should Happen?

Plugin marketplace loads and displays available plugins.

Error Messages/Logs

Failed to load all marketplaces. Errors: claude-plugins-official: Invalid schema: plugins.3.source: Invalid input, plugins.6.source: Invalid input,  
     plugins.14.source: Invalid input, plugins.36.source: Invalid input, plugins.40.source: Invalid input, plugins.57.source: Invalid input,              
     plugins.66.source: Invalid input, plugins.72.source: Invalid input, plugins.75.source: Invalid input, plugins.95.source: Invalid input,              
     plugins.98.source: Invalid input, plugins.108.source: Invalid input, plugins.119.source: Invalid input, plugins.127.source: Invalid input,           
     plugins.128.source: Invalid input, plugins.133.source: Invalid input

Steps to Reproduce

1. Open a terminal
2. Run claude to start Claude Code CLI
3. If not already logged in, run /login and complete authentication (should show "Login successful")
4. Run /plugin to open the plugin browser

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Code v2.1.12

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="1087" height="164" alt="Image" src="https://github.com/user-attachments/assets/f0d047db-bd0d-4306-99cf-3ed98487c6dd" />