Verify Skill

Verify Skill

This skill provides exact schemas and validation rules for Claude Code plugin components.

Exact Schemas

plugin.json Schema

Location: <plugin-root>/plugin.json

{
  "name": "string (required, kebab-case)",
  "version": "string (required, semver)",
  "description": "string (required)",
  "author": {
    "name": "string (required if author present)"
  },
  "license": "string (optional)",
  "repository": "string (optional, URL)",
  "keywords": ["array of strings (optional)"]
}

✅ CORRECT plugin.json:

{
  "name": "my-plugin",
  "version": "1.0.0",
  "description": "A plugin description",
  "author": {
    "name": "Developer Name"
  }
}

❌ WRONG plugin.json examples:

// WRONG: author as string instead of object
{
  "name": "my-plugin",
  "version": "1.0.0",
  "description": "A plugin",
  "author": "Developer Name"  // ❌ Must be object: { "name": "..." }
}

// WRONG: missing required fields
{
  "name": "my-plugin"  // ❌ Missing version and description
}

// WRONG: invalid name format
{
  "name": "My Plugin",  // ❌ Must be kebab-case: "my-plugin"
  "version": "1.0.0",
  "description": "A plugin"
}

marketplace.json Schema

Location: <repo>/.claude-plugin/marketplace.json (in .claude-plugin/ directory)

IMPORTANT: This is for Model B (Marketplace distribution) only. See Directory Structure section.

{
  "$schema": "string (optional, https://claude.ai/schemas/marketplace.json)",
  "name": "string (required, kebab-case)",
  "owner": {
    "name": "string (required)"
  },
  "metadata": {
    "description": "string (optional)",
    "version": "string (optional, semver)"
  },
  "plugins": [
    {
      "name": "string (required)",
      "source": "string (required, path to plugin directory, e.g. ./plugins/name)",
      "description": "string (optional)",
      "version": "string (optional)"
    }
  ]
}

✅ CORRECT marketplace.json:

{
  "$schema": "https://claude.ai/schemas/marketplace.json",
  "name": "my-marketplace",
  "owner": {
    "name": "Team Name"
  },
  "metadata": {
    "description": "Marketplace description",
    "version": "1.0.0"
  },
  "plugins": [
    {
      "name": "my-plugin",
      "source": "./plugins/my-plugin",
      "description": "Plugin description",
      "version": "1.0.0"
    }
  ]
}

❌ WRONG marketplace.json examples:

// WRONG #1: marketplace.json at repo root (wrong location)
// ❌ my-marketplace/marketplace.json               (WRONG - at root)
// ✅ my-marketplace/.claude-plugin/marketplace.json  (CORRECT)

// WRONG #2: source pointing to "./" instead of plugin directory
{
  "plugins": [{
    "name": "my-plugin",
    "source": "./"  // ❌ WRONG: Use "./plugins/my-plugin"
  }]
}

// WRONG #3: source including .claude-plugin path
{
  "plugins": [{
    "name": "my-plugin",
    "source": "./plugins/my-plugin/.claude-plugin"  // ❌ WRONG - don't include .claude-plugin
  }]
}

// WRONG #4: "author" instead of "owner"
{
  "name": "my-marketplace",
  "author": "Team Name",  // ❌ WRONG: Use "owner": { "name": "..." }
  "plugins": []
}

// WRONG #5: "owner" as string instead of object
{
  "name": "my-marketplace",
  "owner": "Team Name",  // ❌ WRONG: Must be object with "name" field
  "plugins": []
}

// WRONG #6: "path" instead of "source" in plugins
{
  "name": "my-marketplace",
  "owner": { "name": "Team" },
  "plugins": [
    {
      "name": "plugin",
      "path": "."  // ❌ WRONG: Use "source": "./plugins/name"
    }
  ]
}

// WRONG #7: "config" object in plugins (not allowed)
{
  "name": "my-marketplace",
  "owner": { "name": "Team" },
  "plugins": [
    {
      "path": ".",
      "config": {  // ❌ WRONG: "config" is not allowed
        "name": "plugin",
        "version": "1.0.0"
      }
    }
  ]
}

// WRONG #8: Extra fields not in schema
{
  "name": "my-marketplace",
  "owner": { "name": "Team" },
  "displayName": "My Marketplace",  // ❌ WRONG: Not in schema
  "license": "MIT",                  // ❌ WRONG: Not in schema
  "repository": "https://...",       // ❌ WRONG: Not in schema
  "keywords": [],                    // ❌ WRONG: Not in schema
  "categories": [],                  // ❌ WRONG: Not in schema
  "requirements": {},                // ❌ WRONG: Not in schema
  "installation": {},                // ❌ WRONG: Not in schema
  "plugins": []
}

Agent Schema

Location: <plugin-root>/agents/<agent-name>.md

---
name: string (required, kebab-case)
description: string (required, when to use this agent)
tools:
  - ToolName (required, array)
model: string (optional: haiku, sonnet, opus)
color: string (optional: blue, cyan, green, yellow, magenta, red)
---

# System Prompt Content

✅ CORRECT agent:

---
name: my-agent
description: Use this agent when analyzing code quality
tools:
  - Read
  - Grep
  - Glob
model: haiku
color: blue
---

# My Agent

You are a code analysis agent...

❌ WRONG agent examples:

# WRONG: File at wrong location
# Location: agents/my-agent/agent.md  ❌
# Correct:  agents/my-agent.md  ✅

# WRONG: Missing required fields
---
name: my-agent
# ❌ Missing description and tools
---

# WRONG: tools as string instead of array
---
name: my-agent
description: An agent
tools: Read, Grep  # ❌ Must be array: ["Read", "Grep"]
---

# WRONG: allowed_tools instead of tools
---
name: my-agent
description: An agent
allowed_tools:  # ❌ WRONG: Use "tools" not "allowed_tools"
  - Read
---

Command Schema

Location: <plugin-root>/commands/<command-name>.md

---
name: string (required, kebab-case)
description: string (required)
allowed-tools:
  - ToolName (optional, array, kebab-case field name!)
argument-hint: string (optional)
---

# Command Content

✅ CORRECT command:

---
name: my-command
description: Runs my command
allowed-tools:
  - Read
  - Write
argument-hint: "<file-path>"
---

# /my-command

Instructions for the command...

❌ WRONG command examples:

# WRONG: allowed_tools (underscore) instead of allowed-tools (hyphen)
---
name: my-command
description: A command
allowed_tools:  # ❌ WRONG: Use "allowed-tools" (kebab-case)
  - Read
---

# WRONG: File at wrong location
# Location: commands/my-command/command.md  ❌
# Correct:  commands/my-command.md  ✅

Skill Schema

Location: <plugin-root>/skills/<skill-name>/SKILL.md

---
name: string (required, kebab-case)
triggers:
  - string (required, array of trigger phrases)
---

# Skill Content

✅ CORRECT skill:

---
name: my-skill
triggers:
  - "use my skill"
  - "activate skill"
---

# My Skill

Skill content...

❌ WRONG skill examples:

# WRONG: File at wrong location
# Location: skills/my-skill.md  ❌
# Correct:  skills/my-skill/SKILL.md  ✅

# WRONG: triggers as string
---
name: my-skill
triggers: "use my skill"  # ❌ Must be array
---

# WRONG: Missing SKILL.md filename
# Location: skills/my-skill/index.md  ❌
# Correct:  skills/my-skill/SKILL.md  ✅

hooks.json Schema

Location: <plugin-root>/hooks/hooks.json

{
  "$schema": "https://claude.ai/schemas/hooks.json",
  "description": "string (optional)",
  "hooks": {
    "EventName": [
      {
        "matcher": "string (optional, regex pattern)",
        "hooks": [
          {
            "type": "command",
            "command": "string (required, with ${CLAUDE_PLUGIN_ROOT})",
            "timeout": "number (optional, seconds)"
          }
        ]
      }
    ]
  }
}

Event names: PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification

✅ CORRECT hooks.json:

{
  "$schema": "https://claude.ai/schemas/hooks.json",
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "^Bash$",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ${CLAUDE_PLUGIN_ROOT}/hooks/validate.py",
            "timeout": 10
          }
        ]
      }
    ],
    "Stop": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "python3 ${CLAUDE_PLUGIN_ROOT}/hooks/stop.py",
            "timeout": 10
          }
        ]
      }
    ]
  }
}

❌ WRONG hooks.json examples:

// WRONG #1: hooks as array instead of object
{
  "hooks": [  // ❌ Must be object keyed by event name
    {
      "event": "PreToolUse",
      "matcher": "^Bash$",
      "command": "..."
    }
  ]
}

// WRONG #2: Using "event" field instead of object key
{
  "hooks": {
    "PreToolUse": [
      {
        "event": "PreToolUse",  // ❌ Don't use event field, it's the object key
        "hooks": [...]
      }
    ]
  }
}

// WRONG #3: Missing nested "hooks" array
{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "^Bash$",
        "command": "..."  // ❌ Must be inside hooks array with type
      }
    ]
  }
}

// WRONG #4: Missing "type": "command"
{
  "hooks": {
    "PreToolUse": [
      {
        "hooks": [
          {
            "command": "python3 script.py"  // ❌ Missing "type": "command"
          }
        ]
      }
    ]
  }
}

// WRONG #5: Hardcoded path
{
  "hooks": {
    "PreToolUse": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "python3 /home/user/hooks/script.py"  // ❌ Use ${CLAUDE_PLUGIN_ROOT}
          }
        ]
      }
    ]
  }
}

Directory Structure

Model A: Standalone Plugin (Local Development)

✅ CORRECT structure:

my-plugin/
├── plugin.json                      # Required at root
├── agents/
│   └── my-agent.md                  # Direct file, not subdirectory
├── commands/
│   └── my-command.md                # Direct file, not subdirectory
├── skills/
│   └── my-skill/
│       └── SKILL.md                 # Must be SKILL.md in subdirectory
└── hooks/
    ├── hooks.json                   # Hook configuration
    └── my-hook.py                   # Hook scripts

Model B: Marketplace (GitHub Distribution)

✅ CORRECT structure:

my-marketplace/                      # Repository root
├── .claude-plugin/
│   └── marketplace.json             # In .claude-plugin/ directory
├── README.md
├── LICENSE
└── plugins/
    └── my-plugin/
        └── .claude-plugin/          # Plugin content HERE
            ├── plugin.json          # Required
            ├── agents/
            │   └── my-agent.md
            ├── commands/
            │   └── my-cmd.md
            ├── skills/
            │   └── my-skill/
            │       └── SKILL.md
            └── hooks/
                ├── hooks.json
                └── my-hook.py

❌ WRONG marketplace structures:

# WRONG: marketplace.json at repo root (should be in .claude-plugin/)
my-marketplace/
├── marketplace.json                 # ❌ Should be in .claude-plugin/
└── plugins/

# WRONG: Plugin content at repo root (not in plugins/ directory)
my-marketplace/
├── .claude-plugin/
│   └── marketplace.json
├── plugin.json                      # ❌ Should be in plugins/<name>/.claude-plugin/
├── agents/                          # ❌ Should be in plugins/<name>/.claude-plugin/
└── skills/                          # ❌ Should be in plugins/<name>/.claude-plugin/

# WRONG: Missing .claude-plugin directory for plugin
my-marketplace/
├── .claude-plugin/
│   └── marketplace.json
└── plugins/
    └── my-plugin/
        ├── plugin.json              # ❌ Missing .claude-plugin/ wrapper
        └── agents/

❌ General WRONG structures:

# WRONG: Agent in subdirectory
agents/my-agent/agent.md  ❌
agents/my-agent.md        ✅

# WRONG: Command in subdirectory
commands/my-command/command.md  ❌
commands/my-command.md          ✅

# WRONG: Skill as direct file
skills/my-skill.md              ❌
skills/my-skill/SKILL.md        ✅

# WRONG: Skill with wrong filename
skills/my-skill/index.md        ❌
skills/my-skill/skill.md        ❌
skills/my-skill/SKILL.md        ✅

Verification Commands

# Validate JSON syntax
python3 -c "import json; json.load(open('file.json'))"

# Validate YAML frontmatter
python3 -c "import yaml; yaml.safe_load(open('file.md').read().split('---')[1])"

# Validate Python syntax
python3 -m py_compile file.py

# Check file exists
test -f path/to/file && echo "EXISTS" || echo "MISSING"

Quick Reference: Common Mistakes

Marketplace Cross-Validation

When validating a marketplace.json, perform these additional cross-checks:

1. Marketplace Location Check

• marketplace.json MUST be in .claude-plugin/ directory
• NOT at repository root

2. Plugin Source Path Validation

For each plugin in the plugins array:

• The source path must follow the pattern: ./plugins/<name> (NOT including .claude-plugin)
• The source directory must contain a .claude-plugin/plugin.json
• Resolve paths relative to .claude-plugin/marketplace.json location

3. Name Consistency Check

• Plugin name in marketplace.json must match the name field in the corresponding plugin.json
• Report mismatches as validation errors

4. Invalid Fields Detection

The following fields are NOT allowed in marketplace.json:

• author at root level (use owner instead)
• path in plugins (use source instead)
• config object in plugins
• source: "./" pointing to root (should point to ./plugins/<name>)
• source including .claude-plugin (should be ./plugins/name not ./plugins/name/.claude-plugin)

Validation should fail if any of these invalid fields are present.

Cross-Validation Commands

# Check marketplace.json is in .claude-plugin/ (not at repo root)
test -f ".claude-plugin/marketplace.json" && echo "CORRECT: In .claude-plugin/" || echo "WRONG: Not in .claude-plugin/"
test -f "marketplace.json" && echo "WRONG: At repo root" || echo "OK"

# Check plugin.json exists at source path (source points to plugin dir, .claude-plugin/plugin.json inside)
SOURCE_PATH="./plugins/my-plugin"
test -f "${SOURCE_PATH}/.claude-plugin/plugin.json" && echo "EXISTS" || echo "MISSING"

# Extract and compare names
MARKETPLACE_NAME=$(python3 -c "import json; print(json.load(open('.claude-plugin/marketplace.json'))['plugins'][0]['name'])")
PLUGIN_NAME=$(python3 -c "import json; print(json.load(open('${SOURCE_PATH}/.claude-plugin/plugin.json'))['name'])")
[ "$MARKETPLACE_NAME" = "$PLUGIN_NAME" ] && echo "MATCH" || echo "MISMATCH: $MARKETPLACE_NAME vs $PLUGIN_NAME"

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