plugin-creator

Plugin Creator

Overview

Scaffolds new Claude Code plugins with proper directory structure, required files, marketplace catalog integration, and full validation. Supports all plugin types: command plugins, agent plugins, skill plugins, MCP server plugins, and hybrid combinations.

Prerequisites

• Write access to the plugins/ directory and .claude-plugin/marketplace.extended.json
• jq installed for JSON generation and validation
• pnpm run sync-marketplace available at the repository root
• ./scripts/validate-all-plugins.sh available for post-creation validation

Instructions

1. Gather requirements from the user request: plugin name (kebab-case), category (productivity, security, devops, testing, etc.), plugin type (commands, agents, skills, MCP, or combination), description, and keywords. Default author to the repository owner if unspecified (see ${CLAUDE_SKILL_DIR}/references/plugin-creation-process.md).
2. Create the plugin directory structure under plugins/[category]/[plugin-name]/:

   plugins/[category]/[plugin-name]/
   ├── .claude-plugin/
   │   └── plugin.json
   ├── README.md
   ├── LICENSE
   └── [commands/ | agents/ | skills/ | hooks/ | mcp/]
   

3. Generate .claude-plugin/plugin.json using the template from ${CLAUDE_SKILL_DIR}/references/file-templates.md. Populate all required fields: name, version (default 1.0.0), description, author (name and email), repository, license (default MIT), and keywords (minimum 2).
4. Generate README.md with installation instructions, usage examples, a description section, and contributor information.
5. Create a LICENSE file with MIT license text (or the specified license).
6. Generate component files based on the plugin type:
   • Commands: create commands/[command-name].md with proper YAML frontmatter (name, description, model).
   • Agents: create agents/[agent-name].md with YAML frontmatter including model field.
   • Skills: create skills/[skill-name]/SKILL.md with frontmatter (name, description, allowed-tools).
   • MCP: create package.json, tsconfig.json, src/index.ts, and .mcp.json.
7. Add the new plugin entry to .claude-plugin/marketplace.extended.json with matching name, version, category, description, source path, and keywords.
8. Run pnpm run sync-marketplace to regenerate marketplace.json.
9. Validate the new plugin by running ./scripts/validate-all-plugins.sh plugins/[category]/[plugin-name]/. Fix any reported issues before completion.

Output

A complete, CI-ready plugin containing:

• All required files (plugin.json, README.md, LICENSE)
• Component files matching the requested plugin type with proper frontmatter
• Marketplace catalog entry in marketplace.extended.json
• Synchronized marketplace.json
• Validation confirmation from validate-all-plugins.sh

Error Handling

Error	Cause	Solution
Plugin name already exists	Duplicate name in plugins/ directory or marketplace catalog	Choose a unique name; check existing plugins with ls plugins/*/
Invalid category	Category not recognized by marketplace schema	Use one of the valid categories: productivity, security, devops, testing, community, examples, packages, mcp
JSON syntax error in generated files	Malformed template output	Run jq empty on each generated JSON file and fix syntax
Marketplace sync failure	New entry has schema violations	Verify all required fields are present in the marketplace.extended.json entry
Validation script failure	Missing required files or incorrect structure	Review the validation output and create/fix the flagged files

Examples

Create a command plugin: Trigger: "Create a new security plugin called 'owasp-scanner' with commands." Process: Create plugins/security/owasp-scanner/ directory, generate plugin.json, README.md, LICENSE, and commands/scan.md with proper frontmatter. Add to marketplace, sync, validate (see ${CLAUDE_SKILL_DIR}/references/examples.md).

Scaffold a skills plugin: Trigger: "Scaffold a skills plugin for code review." Process: Create plugin directory with skills/code-review/SKILL.md containing trigger keywords for code review tasks. Generate plugin.json with appropriate keywords. Add to marketplace, sync, validate.

Create an MCP server plugin: Trigger: "Create a new MCP plugin for database queries." Process: Create plugins/mcp/db-query/ with package.json (including @modelcontextprotocol/sdk dependency), tsconfig.json, src/index.ts, .mcp.json, and standard files. Add to marketplace, sync, validate.

Resources

• ${CLAUDE_SKILL_DIR}/references/plugin-creation-process.md -- detailed creation workflow
• ${CLAUDE_SKILL_DIR}/references/file-templates.md -- templates for plugin.json, commands, agents, and skills
• ${CLAUDE_SKILL_DIR}/references/examples.md -- creation scenario walkthroughs
• ${CLAUDE_SKILL_DIR}/references/errors.md -- error handling patterns