# Create Plugin > This skill should be used when the user asks to "create a plugin", "make a GitHub plugin", "turn my repo into a plugin", "create a Claude Code plugin", "create a Codex plugin", "publish my skills as a plugin", or "set up a plugin marketplace". Scaffolds the complete file structure for a repo that works as both a Claude Code and Codex plugin with marketplace support. - Skill: `alexsmedile/create-plugin` (Agent Skill) - Install (CLI): `npx skillmds@latest add alexsmedile/create-plugin` - Raw SKILL.md: https://api.skillmd.com/api/skills/alexsmedile/create-plugin/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: alexsmedile (https://skillmd.com/u/alexsmedile) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/alexsmedile/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` ```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` ```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` ```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` ```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` ```markdown --- 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` ```markdown --- 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` ```json { "hooks": { "PostToolUse": [ { "matcher": "Write|Edit", "hooks": [ { "type": "command", "command": "echo 'File changed'" } ] } ] } } ``` --- ### If MCP servers selected: `.mcp.json` ```json { "mcpServers": { "example-server": { "command": "${CLAUDE_PLUGIN_ROOT}/bin/server", "args": [] } } } ``` --- ## Step 3: Critical Rules State these clearly before the user creates any files: | Rule | Detail | |------|--------| | `skills/` and `agents/` at **repo root** | Never inside `.claude-plugin/` or `.codex-plugin/` | | Plugin name = skill namespace | Plugin `foo` → skills run as `/foo:skill-name` | | `plugin.json` is auto-discovery | No need to list `skills` or `agents` paths unless using custom locations | | Do NOT add `skills`/`agents` to `marketplace.json` | Causes schema validation error with default `strict: true` | | `source: "./"` in marketplace.json | Points at repo root — correct for single-plugin repos | --- ## Step 4: Git Setup + Install Commands Output these exactly, substituting the user's values: ```bash # 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:** ```bash 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.