[BUG] The official `claude-plugins-official` marketplace fails to load entirely when running `/plugin` 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?

Plugin at index 56 (semgrep) in marketplace.json uses "source": "git-subdir" — a source type not recognized by the schema validator:

```json
{
"name": "semgrep",
"source": {
"source": "git-subdir",
"url": "https://github.com/semgrep/mcp-marketplace.git",
"path": "plugin"
}
}

Supported source types appear to be "url" (object form) and a relative path string (e.g. "./plugins/xxx"). The "git-subdir" type is unrecognized, causing the entire marketplace to
fail — all ~58 plugins become unavailable, not just semgrep.

What Should Happen?

What Should Happen?

Either:

• "git-subdir" source type should be supported by the schema, or
• Invalid individual plugins should be skipped gracefully rather than causing the entire marketplace to fail loading

Error Messages/Logs

Error Messages/Logs

  Failed to load all marketplaces. Errors: claude-plugins-official: Failed to load marketplace "claude-plugins-official" from source (github): Failed to parse marketplace file at
  /root/.claude/plugins/marketplaces/anthropics-claude-plugins-official/.claude-plugin/marketplace.json: Invalid schema:
  /root/.claude/plugins/marketplaces/anthropics-claude-plugins-official/.claude-plugin/marketplace.json plugins.56.source: Invalid input

Steps to Reproduce

1. Have the official claude-plugins-official marketplace configured
2. Open Claude Code in your terminal
3. Run /plugin or /plugin/example-plugin
4. Observe the marketplace load error — no plugins are available

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

4.6

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

• The failure affects the entire marketplace — all ~58 plugins become unavailable, not just the semgrep plugin at index 56
• The issue is reproducible across multiple terminal emulators (iTerm2 and Ghostty), confirming it is not terminal-specific
• Related issues:
• #26555 — different but related schema validation issue with category/source fields leaking into cached plugin.json
• #22310 — official marketplace inaccessibility