Core Concept

Core Concept

Cowork ships with a curated set of connectors for the big apps. It also ships as an open platform - anyone in the community, or your own dev team, can extend it. This chapter covers the extension layer, so you know what you're looking at when you see "install skill" or "install plugin," and so you know what's possible when your favorite tool isn't in the native library.

How It Works (Step-by-Step)

Step 1 - Understand what a skill is

A skill is a small, packaged workflow Cowork can run. Think of it as a specialized assistant for one specific job - "draft a sales contract," "research a competitor," "summarize a meeting transcript." Someone bundled the instructions, the rules, the format, and the trigger conditions. You install the skill, and from then on Cowork knows how to do that job, your way, every time.

Skills are markdown files. That's it. No code.

Step 2 - Understand what a plugin is

A plugin is the next level up. Where a skill is one job, a plugin is a pack - usually a bundle of related skills, sometimes a connector or two, sometimes custom slash commands. Think of it as installing an app on your phone. One click, and Cowork gains a whole department of capabilities. A "Sales" plugin might give you contract drafting, pipeline reports, follow-up emails, and a CRM connector, all installed together.

Step 3 - Browse the marketplace

Inside Cowork there's a marketplace - browse, search, install. One click installs a skill or a plugin into your workspace. Anthropic curates a set of officially-built ones. There's a growing library of community-built ones too.

Step 4 - Understand MCP

Model Context Protocol - MCP - is the open standard behind every connector. You don't need to remember the name. What matters is what it enables: anyone can wrap any tool in MCP, and Cowork will speak to it.

If your favorite niche app isn't in the official marketplace yet, there's a good chance someone in the community has built an MCP server for it. Search, drop it in, done.

Step 5 - Understand custom / internal connectors

The most powerful version of MCP is for your own internal tools. If your company has an internal dashboard, an internal database, or any API of any kind, your dev team can wrap it in MCP and Cowork will treat it exactly like Slack or Gmail. Same interface, same authorization, same approval flow.

You don't have to wait for Anthropic to support your tool - your team can ship it themselves.

Why This Matters

If Cowork doesn't do something you need today, that's almost never a hard no. Skill, plugin, or a small custom MCP server - one of those three unblocks it. Knowing which vocabulary applies to what saves you weeks of confusion when you go looking for solutions.

What Should Be Possible After This

• Explain the difference between a skill, a plugin, and an MCP server.
• Find and install a skill or plugin from the marketplace.
• Recognize when your problem needs a custom connector versus a community one.
• Brief a developer, at a high level, on what to build if a native connector doesn't exist.