Marketplace Visibility Investigation: mermaidjs-v11 & context-engineering

Marketplace Visibility Investigation: mermaidjs-v11 & context-engineering

Date: 2025-12-30 Investigator: debugger subagent ID: a3b2656

Executive Summary

Issue: User reports "mermaidjs-v11" and "context-engineering" skills not visible when installing from plugins marketplace.

Root Cause:

1. mermaidjs-v11: Skill EXISTS and IS properly registered in specialized-tools plugin. NO configuration issue found.
2. context-engineering: Skill does NOT EXIST in repository - never created/added.

Impact:

• mermaidjs-v11: Should be installable via specialized-tools@claudekit-skills - may be UI discovery issue
• context-engineering: Cannot be installed - skill doesn't exist

Technical Analysis

Repository Structure

claudekit-skills/
├── .claude-plugin/
│   └── marketplace.json          # Root marketplace config
├── .claude/skills/               # 28 actual skill directories
│   ├── mermaidjs-v11/           ✓ EXISTS
│   ├── sequential-thinking/     ✓ EXISTS
│   └── ... (26 others)
└── plugins/                      # Plugin categories
    ├── specialized-tools/
    │   ├── .claude-plugin/
    │   │   └── plugin.json       # Plugin metadata
    │   └── skills/
    │       ├── mermaidjs-v11 -> ../../../.claude/skills/mermaidjs-v11 ✓
    │       └── sequential-thinking -> ../../../.claude/skills/sequential-thinking ✓
    └── ... (11 other plugins)

Marketplace Configuration Analysis

Root marketplace.json (.claude-plugin/marketplace.json):

{
  "plugins": [
    {
      "name": "specialized-tools",
      "source": "./plugins/specialized-tools",
      "description": "Specialized skills: sequential-thinking (step-by-step reasoning), mermaidjs-v11 (diagram generation)",
      "version": "1.0.0",
      "keywords": ["diagrams", "reasoning", "visualization"],
      "category": "productivity"
    }
  ]
}

✓ mermaidjs-v11 IS listed in description ✓ Plugin registered correctly

Plugin metadata (plugins/specialized-tools/.claude-plugin/plugin.json):

{
  "name": "specialized-tools",
  "description": "Specialized skills for sequential reasoning and Mermaid diagram generation",
  "version": "1.0.0",
  "author": {"name": "ClaudeKit", "email": "[email protected]"},
  "repository": "https://github.com/mrgoonie/claudekit-skills"
}

✓ Mentions Mermaid diagram generation ✓ Properly configured

Skill File Structure

mermaidjs-v11 (/.claude/skills/mermaidjs-v11/):

mermaidjs-v11/
├── SKILL.md          ✓ Main skill definition with frontmatter
└── references/       ✓ Supporting docs

Frontmatter metadata:

---
name: mermaidjs-v11
description: Create diagrams and visualizations using Mermaid.js v11 syntax...
---

✓ Properly formatted skill definition

Symlink verification:

plugins/specialized-tools/skills/mermaidjs-v11
  -> ../../../.claude/skills/mermaidjs-v11 ✓

Evidence: context-engineering Does NOT Exist

Search results:

# grep -r "context-engineering" /Users/duynguyen/www/claudekit/claudekit-skills/
# (no output)

# find ... -name "context-engineering*" -type f -o -name "context-engineering*" -type d
# (no output)

✗ No skill directory ✗ No references in any config files ✗ No mentions in documentation ✗ Never existed in repository

Comparison: Working vs Reported Skills

Working skills (e.g., frontend-design, ai-multimodal):

• Directory: .claude/skills/{skill-name}/
• File: SKILL.md with frontmatter
• Symlink: plugins/{category}/skills/{skill-name} -> .claude/skills/{skill-name}
• Registered: Listed in plugin description

mermaidjs-v11 (reported as missing): ✓ Has directory ✓ Has SKILL.md with frontmatter ✓ Has symlink ✓ Listed in plugin description → Structure IDENTICAL to working skills

context-engineering (reported as missing): ✗ No directory ✗ No files ✗ No registration → Never existed

Installation Command Analysis

Expected installation:

/plugin marketplace add mrgoonie/claudekit-skills
/plugin install specialized-tools@claudekit-skills

This SHOULD install:

• sequential-thinking ✓
• mermaidjs-v11 ✓ (properly configured)

Skill Discovery Count

# Total skill directories in .claude/skills/
29 directories (includes subdirectories like debugging/*, problem-solving/*)

# Total skill definition files
38 SKILL.md files (includes nested skills)

# Plugin categories
12 plugins in marketplace.json

Root Cause Summary

mermaidjs-v11

Configuration: ✓ CORRECT Structure: ✓ VALID Registration: ✓ PRESENT Symlink: ✓ WORKING

Hypothesis: Issue likely in:

1. Claude Code UI not discovering skills correctly from plugin structure
2. Cache/refresh issue in marketplace UI
3. Skill file format expectation mismatch (SKILL.md vs skill.md)

Evidence against configuration issue:

• Identical structure to working skills (frontend-design, ai-multimodal)
• Properly registered in marketplace.json
• Valid SKILL.md frontmatter format
• Working symlink chain

context-engineering

Status: ✗ DOES NOT EXIST Cause: Skill was never created/added to repository

Evidence:

• No directory in .claude/skills/
• No references in any JSON configs
• No documentation mentions
• grep/find returned zero results

Supporting Evidence

File paths verified:

• Root config: /Users/duynguyen/www/claudekit/claudekit-skills/.claude-plugin/marketplace.json
• Plugin config: /Users/duynguyen/www/claudekit/claudekit-skills/plugins/specialized-tools/.claude-plugin/plugin.json
• Skill location: /Users/duynguyen/www/claudekit/claudekit-skills/.claude/skills/mermaidjs-v11/
• Symlink: /Users/duynguyen/www/claudekit/claudekit-skills/plugins/specialized-tools/skills/mermaidjs-v11

Symlink resolution:

$ readlink plugins/specialized-tools/skills/mermaidjs-v11
../../../.claude/skills/mermaidjs-v11 ✓ VALID

Recommended Investigation Steps

1. Test marketplace installation in clean environment
2. Check Claude Code logs for skill discovery errors
3. Verify marketplace cache/refresh behavior
4. Compare skill.md vs SKILL.md naming expectations
5. Test if skills appear after manual plugin installation

Unresolved Questions

1. Why does mermaidjs-v11 not appear in UI if config is correct?
2. Is there a skill discovery cache that needs clearing?
3. Does Claude Code expect lowercase skill.md instead of SKILL.md?
4. Was context-engineering mentioned in error or planned but not implemented?