plugin-dev

What it is

plugin-dev is a toolkit for developing Claude Code plugins. It gives expert guidance on hooks, MCP integration, plugin structure, and marketplace publishing. It provides seven specialized skills: hook-development, mcp-integration, plugin-structure, plugin-settings, command-development, agent-development, and skill-development. Each skill loads automatically when you ask a relevant question, triggered by phrases like "create a hook", "add MCP server", or "create an agent". The skills use progressive disclosure in three levels. The first is metadata with strong triggers, which is always loaded. The second is a core SKILL.md of about 1,500-2,000 words, loaded when the skill is triggered. The third is detailed references, examples, and working code, loaded as needed. In total the toolkit contains about 11,065 words across 7 SKILL.md files, more than 10,000 words of reference docs, 12+ working examples, and 6 validation, testing, and parsing scripts. The hook-development skill includes validate-hook-schema.sh, test-hook.sh, and hook-linter.sh. plugin-settings adds validate-settings.sh and parse-frontmatter.sh, and agent-development provides validate-agent.sh. The guided /plugin-dev:create-plugin command is an end-to-end workflow with eight phases: 1. Discovery 2. Component Planning 3. Detailed Design 4. Structure Creation 5. Component Implementation 6. Validation 7. Testing 8. Documentation The workflow asks clarifying questions at each phase and loads relevant skills automatically. It uses agent-creator for AI-assisted agent generation and runs validation utilities. The skills cover the following ground: - Hooks: all hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification) and both prompt-based and command hooks. - MCP servers: stdio, SSE, HTTP, and WebSocket server types, plus authentication patterns. - Manifest and layout: the plugin.json manifest and auto-discovery. - Settings: the .claude/plugin-name.local.md settings pattern. - Commands: slash command frontmatter and arguments. - Agents: agent frontmatter with <example> blocks. - Skills: skill writing style. Across all of these, the skills emphasize security, portability via ${CLAUDE_PLUGIN_ROOT}, testing, and documentation.

Who it's for

• Developers building Claude Code plugins from scratch
• Plugin authors adding hooks, MCP servers, commands, agents, or skills to existing plugins
• Developers who want structured, validated plugin development workflows
• Contributors preparing plugins for marketplace distribution

Requirements

Setup

1. Install from the marketplace

   Install the plugin from claude-code-marketplace.

   bashCopy

   /plugin install plugin-dev@claude-code-marketplace

2. Or use directly for development

   Point Claude Code at a local copy of the plugin directory.

   bashCopy

   cc --plugin-dir /path/to/plugin-dev

Examples

/plugin-dev:create-plugin A plugin for managing database migrations

Create a PreToolUse hook that validates file writes

How do I add an MCP server for database access?

# Validate hooks.json structure
./validate-hook-schema.sh hooks/hooks.json

# Test hooks before deployment
./test-hook.sh my-hook.sh test-input.json

# Lint hook scripts for best practices
./hook-linter.sh my-hook.sh