Plugin Building and Packaging Skill

Plugin Building and Packaging

Package your skills, agents, commands, and hooks as distributable plugins.

Plugin Structure

CRITICAL RULE: Only plugin.json goes inside .claude-plugin/. All components go at the plugin ROOT:

my-plugin/                      <- Plugin name = neutral noun
├── .claude-plugin/
│   └── plugin.json             # ONLY this file here!
├── commands/                   # Slash commands (*.md) - imperative verbs
├── agents/                     # Agent definitions (*.md) - role nouns
├── skills/                     # Skills (*/SKILL.md) - ending in -ing
├── hooks/                      # Event handlers (hooks.json)
├── .mcp.json                   # MCP servers (optional)
├── .lsp.json                   # LSP servers (optional)
└── README.md

# ❌ WRONG - components inside .claude-plugin/
.claude-plugin/
├── plugin.json
├── commands/         ← NO!
└── skills/           ← NO!

# ✅ CORRECT - components at plugin root
.claude-plugin/
└── plugin.json
commands/             ← YES!
skills/               ← YES!

plugin.json Manifest

Required fields:

{
  "name": "my-plugin",
  "version": "1.0.0",
  "description": "What this plugin does"
}

With recommended metadata:

{
  "name": "my-plugin",
  "version": "1.0.0",
  "description": "What this plugin does",
  "author": {
    "name": "Your Name",
    "email": "you@example.com"
  },
  "license": "MIT",
  "keywords": ["keyword1", "keyword2"],
  "repository": "https://github.com/user/repo",
  "homepage": "https://github.com/user/repo#readme"
}

See references/plugin-json-schema.md for the complete field reference.

Naming Conventions

See /metaskill-naming for the full naming convention.

Quick reference:

| Component | Form | Example | |-----------|------|---------| | Plugin name | Neutral noun | metaskill, codeforge, datakit | | Skills | -ing (gerund) | metaskill-authoring, metaskill-triggering | | Agents | Role noun | metaskill-trigger-tester, metaskill-analyzer | | Commands | Imperative verb | /metaskill-create, /quick-start |

Plugin name = Common prefix of all atoms

# ✅ GOOD - neutral noun prefix, correct suffixes
metaskill/
├── skills/
│   ├── metaskill-authoring/     # -ing
│   └── metaskill-triggering/    # -ing
├── agents/
│   └── metaskill-trigger-tester.md  # role noun
└── commands/
    └── quick-start.md           # imperative

# ❌ BAD - verb-form prefix
skill-authoring/
├── skills/
│   └── skill-authoring-trigger/  # prefix already -ing!

No type postfixes:

# ❌ BAD - redundant type postfix
skills/code-review-skill/
agents/tester-agent.md
commands/lint-command.md

# ✅ GOOD - no type postfix
skills/code-reviewing/
agents/tester.md
commands/lint.md

Dogfooding Approaches

Quick Iteration (Active Development)

claude --plugin-dir ./my-plugin

Loads plugin immediately
Restart Claude Code to pick up changes
Best for rapid iteration

Marketplace Testing (Pre-Release)

# Add your repo as a local marketplace (once)
/plugin marketplace add /path/to/your/repo

# Install the plugin
/plugin install your-repo@my-plugin

# After changes, reinstall to test
/plugin uninstall your-repo@my-plugin
/plugin install your-repo@my-plugin

Tests the full installation flow
Verifies the user experience
Use before releasing

Plugin Placement in Repos

Single Plugin at Repo Root

For a repo that IS the plugin:

my-plugin-repo/
├── .claude-plugin/
│   └── plugin.json
├── skills/
│   └── my-plugin-authoring/
├── agents/
└── README.md

Plugin Inside a Project (Dogfooding)

For internal tooling within a larger project:

my-project/
├── src/
├── tests/
├── .claude/                  # Project's Claude config
│   └── settings.json
└── plugins/
    └── my-internal-plugin/
        ├── .claude-plugin/
        │   └── plugin.json
        └── skills/

Load with: claude --plugin-dir ./plugins/my-internal-plugin

Multiple Plugins in One Repo

Use marketplace.json to reference multiple plugins:

my-repo/
├── .claude-plugin/
│   └── marketplace.json      # References plugins below
├── plugins/
│   ├── plugin-a/
│   │   ├── .claude-plugin/
│   │   │   └── plugin.json
│   │   └── skills/
│   └── plugin-b/
│       ├── .claude-plugin/
│       │   └── plugin.json
│       └── agents/
└── README.md

marketplace.json (required fields):

{
  "name": "my-marketplace",
  "owner": {
    "name": "Your Name"
  },
  "plugins": [
    { "name": "plugin-a", "source": "./plugins/plugin-a" },
    { "name": "plugin-b", "source": "./plugins/plugin-b" }
  ]
}

With full metadata:

{
  "name": "my-marketplace",
  "owner": {
    "name": "Your Name",
    "email": "you@example.com"
  },
  "metadata": {
    "description": "Description of your marketplace",
    "version": "1.0.0"
  },
  "plugins": [
    {
      "name": "plugin-a",
      "source": "./plugins/plugin-a",
      "description": "What plugin-a does",
      "version": "1.0.0",
      "author": { "name": "Your Name", "email": "you@example.com" },
      "license": "MIT",
      "keywords": ["keyword1", "keyword2"],
      "category": "development"
    }
  ]
}

See references/marketplace-json-schema.md for the complete field reference.

Users can then:

/plugin marketplace add /path/to/my-repo
/plugin install my-marketplace@plugin-a

Internal vs External Plugins

Internal (Dogfooding within Repo)

Place in a plugins/ or tools/ directory:

my-project/
├── plugins/
│   └── internal-tooling/     # For this project only
│       ├── .claude-plugin/
│       │   └── plugin.json
│       └── skills/

Not meant for distribution
Project-specific utilities
Load with --plugin-dir

External (Open Source / Distribution)

Option A: Dedicated plugin repo

my-plugin/                    # Repo IS the plugin
├── .claude-plugin/
│   └── plugin.json
└── skills/

Option B: Plugin marketplace repo

my-plugins/                   # Repo contains multiple plugins
├── .claude-plugin/
│   └── marketplace.json
└── plugins/
    ├── plugin-a/
    └── plugin-b/

Plugin Components Reference

| Directory | Contents | Naming Pattern | |-----------|----------|----------------| | .claude-plugin/ | plugin.json only | N/A | | skills/ | */SKILL.md | prefix-action-ing | | agents/ | *.md | prefix-role-noun | | commands/ | *.md | imperative-verb | | hooks/ | hooks.json | N/A | | .mcp.json | MCP servers | N/A | | .lsp.json | LSP servers | N/A |

Common Mistakes

Components in Wrong Location

# ❌ WRONG
.claude-plugin/
├── plugin.json
└── skills/          # NO! Skills outside .claude-plugin/

# ✅ CORRECT
.claude-plugin/
└── plugin.json
skills/              # YES! At plugin root

Missing plugin.json

# ❌ WRONG - no manifest
my-plugin/
└── skills/

# ✅ CORRECT - has manifest
my-plugin/
├── .claude-plugin/
│   └── plugin.json
└── skills/

Verb-Form Prefix

# ❌ WRONG - prefix is already -ing
skill-authoring/
├── skills/
│   └── skill-authoring-triggering/  # Double verb!

# ✅ CORRECT - neutral noun prefix
metaskill/
├── skills/
│   └── metaskill-triggering/        # Noun + -ing

Related Skills

For naming conventions, see /metaskill-naming
For skill structure and writing, see /metaskill-authoring
For skill group patterns, see /metaskill-grouping
For trigger optimization, see /metaskill-triggering
To test if triggers work, use the metaskill-trigger-tester agent

Agent Skills: Plugin Building and Packaging

Install this agent skill to your local

Skill Files