Mastering Claude Co-Work
Course
Mastering Claude Co-Work
Module 7 of 18

Plugins — Department-Level Automation

Bundle your best Skills and Connectors into installable, shareable packages — and learn when building a plugin is the right decision.

What you'll learn

Distinguish between a Skill, a Connector, and a Plugin — and explain when each is the right tool
Apply the Three-Test Framework to decide whether a workflow deserves its own plugin
Install a community plugin from the marketplace and activate its bundled skills
Create a custom plugin by bundling existing skills and a connector using Plugin Creator

Welcome to Tier B

You just crossed a threshold. Everything in Tier A — setup, folders, connectors, first wins, skills — was about getting Co-Work working reliably for you as an individual. Tier B is about architecture: building systems that are robust, composable, and scalable beyond a single workflow.

Plugins are where that architecture starts. And understanding them requires knowing exactly how they relate to the two things you built in Tier A.

Plugin anatomy diagram: a plugin container holding skills, connectors, and optional sub-agents

The Cookbook Analogy

Community Framework — Brooke Wright

The Cookbook Analogy is a community-created framework by Brooke Wright. It is not official Anthropic terminology. The underlying distinction it describes — between skills, connectors, and plugins — is verified against official documentation.

Brooke Wright's analogy is the clearest mental model for the three-layer stack:

  • Connectors are utensils — the raw tools that give Co-Work access to your apps (Gmail, Notion, Slack). Without them, you can't do anything with the data in those systems.
  • Skills are recipes — individual instruction sets that tell Co-Work how to use those tools to produce a specific output.
  • Plugins are cookbooks — curated collections of recipes plus their required utensils, bundled into one installable package.

A plugin isn't smarter than a skill. It's a delivery mechanism. Its value is bundling: instead of installing three connectors and five skills separately and configuring each one, you install one plugin and everything arrives pre-connected, pre-named, and ready to run.

Official plugin categories include Sales, Marketing, Finance, Design, Engineering, and HR. When you install a Finance plugin, you're getting the connectors (banking, accounting tools), the skills (invoice generation, expense categorization), and the configuration wiring that connects them — all at once.

The Three-Test Framework

Community Framework — Jack Roberts

The Three-Test Framework is a decision model created by Jack Roberts. It is not from Anthropic documentation. The underlying logic — that plugins are most valuable for high-frequency, multi-step, transferable workflows — is sound and consistent with official guidance on plugin use cases.

Before you build anything, run this test. Jack Roberts developed it from watching himself and his clients over-engineer individual skills into plugins when a simpler approach would have worked better — and under-build plugins when they were sitting on the perfect candidate workflow.

Three-Test Framework decision tree: repeat test, chain test, handover test leading to build or don't build

The three tests are:

  1. Repeat test: Do you run this same workflow more than twice a week? If you only do something occasionally, a plugin adds more overhead than value. Stick with individual skills.
  2. Chain test: Does this workflow require two or more skills or connectors working in sequence? A single-skill workflow doesn't need the bundling that plugins provide. When skills depend on each other, bundling them in a plugin ensures they're always configured consistently.
  3. Handover test: Would you give this workflow to a team member to run without coaching? If the workflow is so bespoke that it needs verbal explanation every time, it's not ready to codify into a plugin. Plugins should be self-explanatory to whoever installs them.

Score 2/3: build a plugin. Score 1/3: keep it as individual skills and revisit in a month. Score 0/3: the workflow isn't ready to codify at all — keep iterating on the underlying skills first.

Install Before You Build

The marketplace is the first stop — always. Browse it at Settings → Plugins → Marketplace before spending time building something from scratch. The Co-Work community has already built plugins for most common business workflows: email management, content creation, financial reporting, project tracking.

Search Before You Build

The marketplace grows constantly. A plugin that didn't exist when you last checked may have appeared. Make checking the marketplace a habit before starting any new plugin build. Five minutes of browsing can save two hours of building.

Installing is one click. Once installed, the plugin registers its bundled skills in your Skills library automatically — toggle each one on or off as needed. To customize a bundled skill, use /customize [skill name] or open the skill markdown directly and edit it. You own those skill files once the plugin is installed.

The Critical Installation Rule

When you receive or download a custom plugin as a zip file, upload the zip file exactly as it is. Do not unzip it and re-zip it. The plugin structure relies on the directory layout inside the original zip — unzipping and re-zipping creates a different internal structure that breaks the plugin on import.

Upload as Zip — Do Not Extract

Custom plugins must be uploaded as a zip without extracting. Unzipping and re-zipping breaks the plugin structure. Source: Jack Roberts (Skills course); this is the most common cause of failed plugin installs.

Plugin Creator: Building Your Own

Plugin Creator is a built-in Co-Work tool that interviews you about the workflow you want to bundle and then generates the plugin's manifest and skill files. The workflow:

  1. Navigate to Settings → Plugins → Create New
  2. Describe the plugin's purpose — what domain does it serve, what problem does it solve?
  3. Plugin Creator asks you which skills you want to bundle and which connectors they depend on
  4. It generates the plugin manifest plus the individual skill markdown files
  5. Review everything before testing — check skill names, descriptions, and trigger words
  6. Test by running each bundled skill at least three times before distributing
Plugin vs Skill vs Connector decision matrix for different use cases

What a Plugin Contains

Under the hood, a plugin is a structured zip file containing:

  • A plugin.json manifest — name, description, version, category, required connectors
  • Skill markdown files — one per bundled skill, identical in format to the skills you build manually
  • Optional connector configuration — pre-configured connector settings the skills depend on

Because skills inside a plugin are just markdown files, you can edit them after installation exactly like any other skill. The plugin packaging is just the delivery format — once installed, the skills are yours to modify.

Team and Enterprise: Organization-Wide Distribution

On Team and Enterprise plans, administrators can distribute plugins to every member of the workspace simultaneously. This is a significant capability that community resources rarely cover — it's documented in the official plugin docs but absent from most video walkthroughs.

Team plugin distribution flow: admin uploads plugin, assigns to workspace, all members receive

The distribution flow: admin uploads or builds a plugin → assigns it to a workspace → all workspace members see it in their Skills library. This is how you standardize company-wide workflows — one update to the plugin propagates to every team member's installation.

Practical use case: your team has a proposal writing workflow that has been refined over months. The admin bundles it as a plugin, distributes it to the whole team, and every salesperson now has the same quality workflow available from day one. When the workflow improves, admin updates the plugin and the improvement rolls out everywhere.

The Co-Work OS as a Meta-Plugin

Community Framework — Paul

The Co-Work OS framing is a community-created framework by Paul. It is not an official Anthropic product or feature name. The underlying capability — distributing a comprehensive skill + connector + folder setup as an installable package — is verified.

Paul's Co-Work OS, which you may have encountered in Tier A materials, is itself an example of the plugin pattern taken to its logical conclusion: an entire folder architecture, a curated skill library, connector configurations, and global instruction templates bundled together as an installable package. When someone installs the Co-Work OS plugin, they get a fully configured operating environment, not just one workflow.

This is the power of plugins at scale. You're not just distributing a workflow — you're distributing an entire working environment with opinionated defaults that have been tested and refined.

Build-Along Exercise

Install One Plugin, Build One Custom Plugin

Step 1: Install a marketplace plugin. Browse Settings → Plugins → Marketplace. Find a plugin relevant to your work — Email Manager, Content Creator, Finance Tracker, or another that fits your context. Install it. Navigate to your Skills library and confirm its bundled skills have appeared. Run at least one bundled skill.

Step 2: Apply the Three-Test Framework. Take a workflow you already have from Modules 5–6. Score it against the three tests: Repeat (2x/week?), Chain (2+ skills/connectors?), Handover (transferable without coaching?). Note your score. If 2/3: proceed to Step 3.

Step 3: Build a custom plugin with Plugin Creator. Navigate to Settings → Plugins → Create New. Describe your plugin's purpose. Select two skills from your existing library. Select one connector they depend on. Generate via Plugin Creator. Review the manifest and skill files. Test by running each bundled skill.

Success criteria: One marketplace plugin installed with at least one bundled skill run. One custom plugin created, visible in the Skills library, and tested successfully.

Knowledge Check
I can explain the difference between a Skill, a Connector, and a Plugin without looking it up — and the Cookbook Analogy is the mental model I'll use
I applied the Three-Test Framework to at least one workflow and know whether to build a plugin or keep individual skills
I installed a marketplace plugin and ran at least one of its bundled skills successfully
I know that custom plugins must be uploaded as a zip without extracting — extracting and re-zipping breaks the structure
I understand how Team/Enterprise plugin distribution works and the use case it solves