Plugins

A plugin is the distribution unit. Where a Skill is one packaged capability, a plugin is a bundle you install once that can bring several things with it: skills, slash commands, hooks, MCP servers and subagent definitions.

Marketplaces

Plugins are discovered and installed through marketplaces, and anyone can publish one — Anthropic documents creating and distributing your own, constraining dependency versions, recommending plugins from your CLI, and setting organisational plugin relevance.

That last set of pages is the tell that this is aimed at teams: an organisation can steer which plugins its developers see, rather than leaving discovery entirely to individuals.

Not just Claude Code

Plugins started in Claude Code but now also customise Cowork. Treating them as a Claude Code feature will leave you surprised.

What it does not do

• It is not a sandbox. Installing a plugin can install hooks that run shell commands and MCP servers that hold credentials. A plugin is code you are choosing to run.
• It is not versioned automatically for you. Dependency-version constraints exist precisely because plugin updates can break a workflow.
• It is not a Skill, and a Skill is not a plugin. See Plugins vs Skills.

Before installing a community plugin

Read what it contains. The three things worth checking every time: what hooks it registers, what MCP servers it configures, and what permissions those imply. Everything in this reference’s ecosystem directory that is not maintained by Anthropic carries that warning for a reason.