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: prompt-based and command hooks, all hook events, output formats, security practices, and ${CLAUDE_PLUGIN_ROOT}. - MCP Integration: stdio, SSE, HTTP and WebSocket servers, authentication patterns, and tool naming. - Plugin Structure: directory layout, auto-discovery, and the plugin.json manifest. - Plugin Settings: the .claude/plugin-name.local.md pattern with YAML frontmatter. - Command Development: slash command format, frontmatter, and arguments. - Agent Development: frontmatter, <example> blocks for triggering, system prompt design, and AI-assisted generation. - Skill Development: progressive disclosure and strong trigger descriptions. The skills load automatically when you ask relevant questions. Each one uses a three-level progressive disclosure system: 1. Metadata with strong triggers, always loaded. 2. A core SKILL.md of roughly 1,500-2,000 words, loaded when triggered. 3. References and examples, loaded as needed. This keeps Claude Code's context focused. In total the toolkit includes about 11,065 words of core skill content, 10,000+ words of reference docs, 12+ working examples, and 6 validation, testing and parsing utility scripts. The toolkit also includes the /plugin-dev:create-plugin command. It is an end-to-end, 8-phase workflow: 1. Discovery 2. Component Planning 3. Detailed Design 4. Structure Creation 5. Component Implementation 6. Validation 7. Testing 8. Documentation Along the way, the command asks clarifying questions, loads relevant skills, uses agent-creator for AI-assisted agent generation, and runs validation utilities such as validate-agent.sh and validate-hook-schema.sh. The plugin is authored by Daisy Hollman, is at version 0.1.0, and is MIT licensed.

Who it's for

• Developers building Claude Code plugins from scratch
• Plugin authors adding hooks, MCP servers, commands, agents or skills
• Developers making plugins configurable with per-project settings
• Contributors preparing plugins for the claude-code-marketplace

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

What's the best directory structure for a plugin with commands and MCP integration?

# 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