example-plugin

plugin-marketplace-template

A multi-plugin workspace for building Claude Code plugins with skills, MCP tools, and an OAuth-protected HTTP server, ready to deploy to any cloud.

Use skills from this template

You can use skills from plugins in this repo by connecting marketplace to Claude, or adding the skills specifically:

npx skills add varianter/plugin-marketplace-template

# list all
npx skills add varianter/plugin-marketplace-template --list

Keep in mind that if you add a skill that refers to MCP tools outside of Claude marketplace, you would have to connect to MCP server manually.

What's included

• @variant/mcp-server — npm package for shared MCP infrastructure: Express server, OAuth/OIDC auth, session management, widget support
• plugins/standard — starter plugin with a whoami tool and example skill
• Build and validation scripts — typecheck, lint, skill validator, widget bundler

Getting started

git clone https://github.com/varianter/plugin-marketplace-template
cd plugin-marketplace-template
cp .env.example .env          # fill in your auth credentials and config
pnpm install

Then update plugins/standard/mcp-server.config.json with runtime configurations. See below for details.

Run a plugin's MCP server locally:

pnpm dev standard             # hot-reload server + widget watcher
pnpm dev                      # choose from available plugins
pnpm dev:server standard      # server only — faster when not touching widgets

When having multiple plugins, you can run

pnpm dev <plugin>             # hot-reload server + widget watcher
pnpm dev:server <plugin>      # server only — faster when not touching widgets

Then update plugins/standard/.claude-plugin/plugin.json with your MCP server URL once deployed.

Configuration MCP

Runtime defaults live in plugins/standard/mcp-server.config.json — the file is found by walking up from the server process's working directory, so keep it at the plugin root. Environment variables override these values at runtime. See docs and readme at @variant/mcp-server for complete configuration.

Project structure

plugins/
  standard/          ← starter plugin (copy this to add a new plugin)
    .claude-plugin/
      plugin.json    ← plugin manifest (skills paths, MCP server URL)
    mcp-server.config.json ← committed runtime defaults for this plugin's MCP server
    skills/          ← skills; each skill may optionally contain a tools/ directory for colocated tools
    skills/*/tools   ← MCP tools colocated with a skill (optional)
    tools/           ← standalone MCP tools (not tied to a skill)
    mcp-server/      ← deployable MCP HTTP server for this plugin
.claude-plugin/
  marketplace.json   ← repo-level manifest listing all plugins
scripts/             ← skill validator and packaging tools

Adding a skill

Create plugins/standard/skills/<name>/SKILL.md. If the skill needs MCP tools, add them under plugins/standard/skills/<name>/tools/:

---
name: my-skill
description: One-line description shown in the skill picker
---

Skill instructions here.

Validate it:

pnpm validate-skill plugins/standard/skills/my-skill

Adding an MCP tool

Create plugins/standard/tools/<name>/<toolName>.ts with an explicit registrar:

import type { McpServer } from '@variant/mcp-server';
import { z } from 'zod';

export function registerMyTool(server: McpServer): void {
  server.registerTool(
    'my-tool',
    { title: 'My Tool', description: 'Does something useful', inputSchema: { param: z.string() } },
    async ({ param }) => ({ content: [{ type: 'text', text: param }] }),
  );
}

Then add it to plugins/standard/mcp-server/registerTools.ts:

import { definePluginTools } from '@variant/mcp-server';
import { registerMyTool } from '../tools/my-tool/myTool.js';

export const registerTools = definePluginTools([registerMyTool]);

For skill-colocated tools (tools under a skill's tools/ directory) see AGENTS.md.

Note: You can also use the create-plugin-skill skill in .agents/skills/create-plugin-skill/SKILL.md to generate a new skill directory with the correct structure.

Adding a new plugin

1. Copy plugins/standard/ to plugins/<name>/ 2. Update plugins/<name>/.claude-plugin/plugin.json and plugins/<name>/package.json 3. Add the new plugin to .claude-plugin/marketplace.json 4. Add it to the plugin matrices in .github/workflows/ci.yml and .github/workflows/deploy.yml

Note: You can also use the create-plugin skill in .agents/skills/create-plugin/SKILL.md to generate a new plugin directory with the correct structure.

Development commands

From the repo root:

pnpm dev [plugin]        # selected plugin — server + widget watcher (hot-reload)
pnpm dev:server [plugin] # selected plugin — server only (faster, skips widgets)
pnpm dev:standard        # standard plugin alias
pnpm build               # build all plugin servers
pnpm typecheck           # type-check workspace packages
pnpm check               # biome lint + format check
pnpm fix                 # biome auto-fix
pnpm validate-skills      # validate all skills
pnpm validate-skill <path> # validate a single skill, e.g. plugins/standard/skills/my-skill

Additional commands available from plugins/standard/:

pnpm inspect       # official MCP Inspector

Deployment

Trigger the Deploy GitHub Actions workflow from the repository UI. Select a plugin (or "all") and environment. Each plugin has its own Docker image (<plugin>-mcp) built from plugins/<plugin>/mcp-server/Dockerfile.

Docker builds install @variant/mcp-server from npm, so publish the package before building images from this template.

Update the registry and deployment target in .github/workflows/deploy.yml to match your infrastructure.

See CLAUDE.md for the full structure reference and AGENTS.md for the tool authoring guide.