Create Plugin

Skill: Plugin Creator (Claude Code + Codex)

Purpose

Scaffold a GitHub repo that works as a plugin for both Claude Code and Codex simultaneously. Outputs ready-to-copy file contents and git commands for every required file.

Step 1: Gather Inputs

Ask the user these questions (all at once):

1. Repo name — kebab-case (e.g. my-skills)
2. GitHub username or org — (e.g. alexsmedile)
3. Plugin description — one sentence
4. Author name
5. What does this plugin contain? — pick all that apply:
   • Skills (skills/)
   • Agents (agents/)
   • Hooks (hooks/hooks.json)
   • MCP servers (.mcp.json)
6. License — default: MIT

Do not proceed until you have at least: repo name, GitHub username, description, and author name.

Step 2: Generate File Structure

Show the full directory tree based on their selections, then output every file's content ready to copy.

Always-required files

.claude-plugin/plugin.json

{
  "name": "{{repo-name}}",
  "version": "1.0.0",
  "description": "{{description}}",
  "author": {
    "name": "{{author}}"
  },
  "homepage": "https://github.com/{{username}}/{{repo-name}}",
  "repository": "https://github.com/{{username}}/{{repo-name}}",
  "license": "{{license}}",
  "keywords": []
}

Skills and agents in skills/ and agents/ are auto-discovered — no paths needed in plugin.json.

.claude-plugin/marketplace.json

{
  "name": "{{repo-name}}",
  "owner": {
    "name": "{{author}}"
  },
  "metadata": {
    "description": "{{description}}",
    "version": "1.0.0"
  },
  "plugins": [
    {
      "name": "{{repo-name}}",
      "source": "./",
      "description": "{{description}}",
      "version": "1.0.0",
      "author": {
        "name": "{{author}}"
      },
      "homepage": "https://github.com/{{username}}/{{repo-name}}",
      "repository": "https://github.com/{{username}}/{{repo-name}}",
      "license": "{{license}}",
      "category": "productivity"
    }
  ]
}

.codex-plugin/plugin.json

{
  "name": "{{repo-name}}",
  "version": "1.0.0",
  "description": "{{description}}",
  "author": {
    "name": "{{author}}"
  },
  "homepage": "https://github.com/{{username}}/{{repo-name}}",
  "repository": "https://github.com/{{username}}/{{repo-name}}",
  "license": "{{license}}",
  "skills": "./skills/"
}

.codex-plugin/marketplace.json

{
  "name": "{{repo-name}}",
  "interface": {
    "displayName": "{{repo-name}}"
  },
  "plugins": [
    {
      "name": "{{repo-name}}",
      "source": {
        "source": "local",
        "path": "./"
      },
      "category": "Productivity"
    }
  ]
}

.gitignore

.DS_Store
**/.DS_Store
output/*
!output/.gitkeep

output/.gitkeep

Empty file — keeps the output/ folder tracked by git.

If skills selected: skills/example-skill/SKILL.md

---
name: example-skill
description: Replace this description with specific trigger phrases. Use when the user asks to "..."
---

# Skill: Example

Describe what this skill does and how to use it.

Rename example-skill/ to your actual skill name. Skill is invoked as /{{repo-name}}:example-skill.

If agents selected: agents/example-agent.md

---
name: example-agent
description: Replace with what this agent does and when to invoke it.
tools: Read, Write, Bash
model: sonnet
---

# Agent: Example

Describe the agent's role, expertise, and behavior here.

Rename to your actual agent name.

If hooks selected: hooks/hooks.json

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Write|Edit",
        "hooks": [
          {
            "type": "command",
            "command": "echo 'File changed'"
          }
        ]
      }
    ]
  }
}

If MCP servers selected: .mcp.json

{
  "mcpServers": {
    "example-server": {
      "command": "${CLAUDE_PLUGIN_ROOT}/bin/server",
      "args": []
    }
  }
}

Step 3: Critical Rules

State these clearly before the user creates any files:

Step 4: Git Setup + Install Commands

Output these exactly, substituting the user's values:

# Create repo (if not exists)
gh repo create {{username}}/{{repo-name}} --public

# Init and push
git init
git add .
git commit -m "feat: initial plugin scaffold"
git remote add origin https://github.com/{{username}}/{{repo-name}}.git
git push -u origin main

Install in Claude Code:

/plugin marketplace add {{username}}/{{repo-name}}
/plugin install {{repo-name}}@{{repo-name}}

Reload after changes:

/reload-plugins

Test locally without installing:

claude --plugin-dir ./

Step 5: After Install

Skills are namespaced: /{{repo-name}}:skill-name
Agents appear in /agents

To update: push to GitHub, then /plugin marketplace update {{repo-name}}

Bump version in plugin.json and marketplace.json with each release — Claude Code uses version to detect updates.