Claude Code Plugins: Install, Use, and Build Your Own

For most of Claude Code's life, sharing your setup meant a README: "copy these files into .claude/agents/, add this to settings, run claude mcp add…" Plugins replace that with a real distribution format — one installable, versioned package that can carry your whole toolkit.

What a plugin can bundle

Any combination of:

• Skills — on-demand procedures (skills/<name>/SKILL.md), invoked as /plugin-name:skill-name
• Agents — subagent definitions (agents/*.md)
• Slash commands — (commands/*.md, the older flat format; new plugins should prefer skills)
• Hooks — lifecycle automation (hooks/hooks.json), same shape as settings hooks
• MCP servers — a bundled .mcp.json, so installing the plugin connects its integrations
• LSP servers — code-intelligence config that gives Claude go-to-definition instead of text search
• Output styles, themes, and background monitors round out the list.

That composability is the point: a "Sentry debugging" plugin can ship the MCP server and a subagent that knows how to use it and the hook that triggers it — one install instead of three setup steps.

Installing plugins

/plugin opens the interactive browser (Discover / Installed / Marketplaces tabs). The direct commands:

/plugin install <name>@<marketplace>     # install
/plugin disable <name>                   # switch off without uninstalling
/plugin details <name>                   # see components and context cost
/plugin marketplace add <source>         # register a marketplace

Anthropic's official marketplace (claude-plugins-official) is preregistered — it carries first-party integrations (GitHub, Figma, Slack, language LSPs, and more). A marketplace is just a repo with a marketplace.json, so adding more is one command with a GitHub owner/repo, a git URL (private/SSH works), a local path, or a hosted JSON URL. Real-world examples you can try today: /plugin install figma@claude-plugins-official for Figma's design tools, or /plugin marketplace add cloudflare/skills for Cloudflare's.

Two details that matter day-to-day:

• Namespacing. Plugin components are prefixed — /commit-commands:commit, Agent(security-plugin:auditor) — so same-named components from different plugins never collide.
• Scopes. Like settings, plugins install at user scope by default; --scope project records them for the whole repo, so teammates get the team baseline after a one-time trust prompt.

Building your own

A plugin is a directory; only the manifest lives in the .claude-plugin/ folder, everything else sits at the root:

my-plugin/
├── .claude-plugin/
│   └── plugin.json        # the manifest — only this goes in .claude-plugin/
├── skills/
│   └── release-notes/
│       └── SKILL.md
├── agents/
│   └── reviewer.md
├── hooks/
│   └── hooks.json
└── .mcp.json              # MCP servers to connect on install

The manifest needs one field; the rest is metadata and overrides:

{
  "name": "my-plugin",
  "version": "1.0.0",
  "description": "Release tooling: changelog skill, reviewer agent, format hooks",
  "author": { "name": "Your Team" }
}

Three variables make bundled code portable: ${CLAUDE_PLUGIN_ROOT} (the plugin's install directory — use it in hook commands and MCP configs), ${CLAUDE_PLUGIN_DATA} (a persistent data directory that survives updates — caches, venvs), and ${CLAUDE_PROJECT_DIR} (the project being worked on).

Test locally, then publish:

claude --plugin-dir ./my-plugin    # load it for one session
# iterate without restarting: /reload-plugins
claude plugin validate ./my-plugin # lint the manifest before shipping

Publishing is listing it in a marketplace: add a marketplace.json to any repo naming your plugins and their sources, and consumers run /plugin marketplace add your-org/your-repo. For a team, that repo becomes the tooling registry — update the plugin, everyone pulls the new version.

When to reach for a plugin

Use the lighter mechanisms when they're enough — a single skill for one procedure, a custom agent file for one specialist, plain settings for one project's config. Reach for a plugin when the value is in the bundle (skill + agent + hook + MCP that work together) or in distribution (more than one person, more than one repo, versioned updates). That's also why plugins are how vendors now ship Claude Code integrations — and why your internal platform team probably wants one.