Claude Code plugins: marketplaces, installing, and building your own

What a plugin contains

A skill does one job. A plugin ships a working set: say, a review skill, a /review command, a reviewer subagent and a hook that runs the linter after edits. Enable the plugin and all of it appears; disable it and all of it goes away.

Folder layout per the reference:

my-plugin/
  .claude-plugin/plugin.json   manifest (optional)
  skills/<name>/SKILL.md
  commands/*.md
  agents/*.md
  hooks/hooks.json
  .mcp.json
  .lsp.json
  output-styles/
  settings.json

Components are namespaced as plugin:component, so two plugins can both ship /review without a clash. A CLAUDE.md at the plugin root is not loaded; put instructions in skills.

How to install a Claude Code plugin

Add the marketplace first, then install from it:

/plugin marketplace add owner/repo
/plugin install plugin-name@marketplace-name

From a shell: claude plugin marketplace add <owner>/<repo> (or a URL, or a local folder) and claude plugin install <name>@<marketplace>. Plain /plugin opens a menu with installed plugins and known marketplaces.

The official Anthropic marketplace is added by default. The anthropics/skills repo also installs as a marketplace: /plugin marketplace add anthropics/skills.

For a team, declare marketplaces and plugins in project settings (extraKnownMarketplaces, enabledPlugins) and teammates get them without manual installs.

Official Anthropic plugin catalogs

Numbers taken on 2026-10-24.

Third-party marketplaces on GitHub number in the thousands: awesomeclaudeplugins.com counted 136,291 plugins across 51,324 repos on the same date. An automated scan is not your review. A plugin hook runs code on your machine. Vetted plugins with license and stars in the trust passport are in Plugins and the best Claude Code plugins list.

plugin.json: the plugin manifest

.claude-plugin/plugin.json is optional; without it Claude Code finds components in the default folders. If it exists, only name is required, in kebab-case. Prefixes such as claude-, anthropic- and cc-plugin- are not allowed.

{
  "name": "team-review",
  "version": "0.1.0",
  "description": "Pre-commit review: skill, command and linter hook",
  "license": "MIT"
}

Optional fields: version, description, author, license, keywords, dependencies, userConfig, mcpServers. Hook and MCP paths can use ${CLAUDE_PLUGIN_ROOT}, ${CLAUDE_PLUGIN_DATA} and ${CLAUDE_PROJECT_DIR}.

One catch: subagents shipped in a plugin ignore hooks, mcpServers and permissionMode.

marketplace.json: running your own marketplace

A marketplace is any git repo with .claude-plugin/marketplace.json. Required: name, owner with a name, and a plugins array where each entry has name and source.

{
  "name": "acme-tools",
  "owner": { "name": "Acme" },
  "plugins": [
    { "name": "team-review", "source": "./plugins/team-review" },
    { "name": "db-guard", "source": { "source": "github", "repo": "acme/db-guard" } }
  ]
}

source can be a relative path, a GitHub repo, a git subdirectory, a URL, an archive, an npm package or a command. Official marketplace names such as claude-plugins-official are reserved. Details in the marketplace docs.

Testing a plugin before you publish

• claude plugin validate ./my-plugin checks the structure and manifest;
• claude --plugin-dir ./my-plugin starts a session with the plugin loaded from disk, no marketplace needed;
• after changes, reload and confirm the commands show up under the plugin prefix.

Planning to support other agents too? Cursor imports GitHub plugins through its own .cursor-plugin/marketplace.json, Gemini CLI has extensions with gemini-extension.json, and Codex installs plugins via /plugins. What ports as is: mostly the skills, because every agent reads SKILL.md. The config formats guide covers the rest.