Plugin Structure

A guide to organizing Claude Code plugins, including their manifest file and folders for commands, agents, skills, hooks, tool servers, and scripts.

In plain words
What is it for?
Use it when creating a plugin, setting up its plugin.json file, adding commands or skills, configuring hooks, or learning how to reference plugin files portably.
Why use it?
It explains where each plugin component belongs and how Claude Code discovers it. This helps prevent broken paths and disorganized plugin projects.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/tzachbon/smart-ralph/plugin-structure
Any agent
npx skills add tzachbon/smart-ralph --skill plugin-structure
Clone the repo
git clone --depth 1 https://github.com/tzachbon/smart-ralph

Made for: Claude Code, Codex.

Per session 92 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,217 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00092 $0.03217
Opus 5 $0.00046 $0.01608
Sonnet 5 $0.00018 $0.00643
Haiku 4.5 $0.00009 $0.00322

Measured 2d ago against content hash ee28fd415353, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Plugin Structure scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

8 near-identical copies found in the catalogue:

.agents/skills/Plugin Structure/SKILL.md · 477 lines

How it starts

The opening of the file, as written. The whole thing — 477 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plugin Structure for Claude Code

Overview

Claude Code plugins follow a standardized directory structure with automatic component discovery. Understanding this structure enables creating well-organized, maintainable plugins that integrate seamlessly with Claude Code.

Key concepts:

  • Conventional directory layout for automatic discovery
  • Manifest-driven configuration in .claude-plugin/plugin.json
  • Component-based organization (commands, agents, skills, hooks)
  • Portable path references using ${CLAUDE_PLUGIN_ROOT}
  • Explicit vs. auto-discovered component loading

Directory Structure

Every Claude Code plugin follows this organizational pattern:

plugin-name/
├── .claude-plugin/
│   └── plugin.json          # Required: Plugin manifest
├── commands/                 # Slash commands (.md files)
├── agents/                   # Subagent definitions (.md files)
├── skills/                   # Agent skills (subdirectories)
│   └── skill-name/
│       └── SKILL.md         # Required for each skill
├── hooks/
│   └── hooks.json           # Event handler configuration
├── .mcp.json                # MCP server definitions
└── scripts/                 # Helper scripts and utilities

Critical rules:

  1. Manifest location: The plugin.json manifest MUST be in .claude-plugin/ directory
  2. Component locations: All component directories (commands, agents, skills, hooks) MUST be at plugin root level, NOT nested inside .claude-plugin/
  3. Optional components: Only create directories for components the plugin actually uses
  4. Naming convention: Use kebab-case for all directory and file names

Plugin Manifest (plugin.json)

The manifest defines plugin metadata and configuration. Located at .claude-plugin/plugin.json:

Required Fields

{
  "name": "plugin-name"
}

Name requirements:

  • Use kebab-case format (lowercase with hyphens)
  • Must be unique across installed plugins
  • No spaces or special characters
  • Example: code-review-assistant, test-runner, api-docs

Read the full file on GitHub · 477 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 477 lines · 92 tokens per session scan A ee28fd415353

Subscribe to this mod's changes

Plugin Structure is a skill published in the GitHub repository tzachbon/smart-ralph (527 stars, last pushed 4d ago), licensed MIT. It adds 92 tokens to every session and 3,217 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.