The complete guide to Skills, Cowork, and Plugins

Investors coined a new term: "SaaSpocalypse."

Not because of a new chatbot. Because Cowork turns Claude from a chat window into something that reads your files, organises your folders, drafts your documents, and runs multi-step workflows you used to delegate to a team.

Today we're fixing that. Sabahudin and I are breaking down Skills and Cowork together. No technical background needed.

If you've ever written a checklist, you have everything you need.

Claude Opus 4.6

Quick note before we start.

Claude Opus 4.6 launched this week. The context window jumped to 1M tokens.

That means Claude now:

→ Reads an entire book in one go
→ Processes your whole codebase at once
→ Holds conversations that don't cut off halfway through

For months, Claude's small context window was its biggest weakness. Conversations got cut short. Documents got lost. Every other frontier model handled more.

That's gone now.

What still lets it down: the API is still expensive, and Gemini handles images and video better.

But for strategic thinking, long-form writing, deep research, and coding? Nothing touches it right now.

For everything in this newsletter, Opus 4.6 is the model to use. Select it in the model dropdown (Pro/Max only).

Skills require a Pro, Max, Team, or Enterprise plan. Team and Enterprise users: your admin must enable Skills first in organisation settings.

Set Up Claude Properly First

Before building Skills, turn on these three settings. They make everything work better.

1. Memory (Settings > Personalisation > Enable Memory). Not on by default. Once enabled, Claude remembers preferences across all chats. Add custom instructions in "User Preferences." Works with Projects too.
   
   
2. Extended Thinking (Enable in settings or per-message). Claude reasons step-by-step before answering. You see the thinking in grey text. Uses more tokens but way better accuracy.
   
   
3. Projects (For long-running work). Organise work by client, research topic, or content series. Upload files as persistent context. Add Project Instructions (like Skills but project-specific). All chats in the project share context.
   
   

Memory works across Projects. Your preferences follow you everywhere.

What a Skill Is (and Isn't)

Think about training a new employee.

Day 1, you explain how to write your reports. Day 2, you explain it again. Day 3, same thing.

By week two, you're exhausted.

Now imagine you wrote everything down once. Your new hire reads it, follows it, delivers the work exactly how you want. Every time.

A Claude Skill is that written guide.

You create it once. Claude follows it from that point forward.

The difference between a Skill and a prompt: a prompt disappears when the conversation ends. A Skill persists. It lives in your account, ready to activate whenever the task matches.

Skills also load smarter. Claude reads the name and description first, then pulls in the full instructions only when needed. Your context window stays clean. Your tokens go further.

Three things Skills do:

Package your workflows. Monthly reports, client emails, content briefs. Write the process once, use it forever.

Add specialised knowledge. Your templates, your tone, your rules. The difference between a generic assistant and one that sounds like your team.

Stack with built-in abilities. Your lead qualification Skill works alongside Claude's Excel Skill. One prompt scores 20 prospects, colour-codes by priority, and exports a spreadsheet. Two Skills. One prompt. Output ready to send.

Skills follow an open standard. You build in the web app. Use in Claude Code or Cowork. Share across your team. You're building an asset, not a prompt that dies when the chat ends.

How to Build Your First Skill

No code required.

Open a new Claude chat and type:

"I want to create a Skill for writing weekly client updates."

Claude asks about your process. You answer naturally. It generates the Skill file automatically. You review it, select "Copy to your skills", done.

The workflow:

1. Start a new Claude conversation
2. Describe the task you want to systematise
3. Share examples of good output
4. Claude builds the Skill file
5. Select "Copy to your skills"
6. Test it in a new conversation

The thing that makes the biggest difference: feed Claude real examples.

"Write a client email" produces a generic Skill. Pasting in three actual client emails you've sent, with notes on what makes them good, produces a Skill that sounds like you.

If you already have a conversation where Claude nailed the output, type: "Create a skill to remember this."

Claude saves your preferences automatically. One sentence turns a good conversation into a permanent Skill.

What a Skill File Looks Like

Every Skill is a folder containing a SKILL.md file. The file starts with YAML frontmatter:

---

name: weekly-client-updates

description: Writes weekly client updates in my tone. Use when user asks for "client update", "weekly report", or "status summary".

---

The description field is critical. It tells Claude when to load your Skill. Include what it does and specific phrases that should trigger it.

Shortcut: use the skill-creator skill. Claude has a built-in skill for building skills. Type:

"Use the skill-creator skill to help me build a skill for [your use case]"

It walks you through use case definition, generates the frontmatter, writes the instructions, and validates the output.

Now Add Cowork

Skills = the instructions. Cowork = the engine.

Without Cowork, Skills work inside Claude's chat window. You type, it responds. Useful, but limited to conversation.

With Cowork, Claude accesses your local files, creates documents, organises folders, fills spreadsheets, and runs multi-step workflows.

Chat is a conversation. Cowork is delegation.

What you need: macOS Desktop app and granted folder access.

Your Skills work inside Cowork. That's where the power compounds.

What Cowork does:

→ Local File Access. Read, edit, create files in granted folders. No uploads needed. → Sub-Agents. Coordinates parallel workstreams. Tasks run in parallel. → Pro Outputs. Creates Excel, PowerPoint, Word, PDFs. Deliverables, not drafts. → Chrome Control. Clicks, fills forms, reads pages. Files + web in one flow. → Plugins. Skills + commands for job roles. Domain expertise in one install. → Long Tasks. No timeouts or context limits. Return to finished work.

Here's the difference in practice.

In chat: You paste invoice details, Claude gives you a formatted summary.

In Cowork: You point Claude at a folder of invoice PDFs. It reads every document, extracts client names, amounts, dates, and payment terms, builds a reconciliation spreadsheet with overdue flags, and saves the file. You come back to a finished accounts summary.

Example prompt:

"I have a folder of client invoices at /Documents/Invoices/February-2026. For each invoice, extract the invoice number, client name, invoice date, due date, line items, and total amount. Create an Excel spreadsheet with one row per invoice. Add a column that flags anything overdue based on today's date. Include a summary row with total invoiced, total overdue, and total paid. Save as february-2026-invoice-summary.xlsx."

One prompt replaces 30 minutes of manual data entry.

What to Say to Cowork

Prompts you copy and use today:

→ Organise Files: "Organise my Downloads folder by file type and date"
→ Build Reports: "Create an expense report from these receipt screenshots"
→ Draft Documents: "Draft a quarterly review from my Q4 folder notes"
→ Research: "Research competitor pricing, create comparison spreadsheet"
→ Automate Browser: "Check Gmail and summarise urgent client messages"
→ Triage Inbox: "Scan today's emails and Slack, update my task list"
→ Presentations: "Create a 12-slide investor pitch from this folder"
→ Review Contracts: "/review-contract, flag risky clauses red/yellow/green"
→ Build a Plugin: "Build a plugin for our content team with brand voice"
→ Parallel Tasks: "Task 1: Organise. Task 2: Draft report. Task 3: Email summary."

Skills + Cowork + Plugins

Here's the mental model.

→ Skills teach Claude your processes
→ Cowork gives Claude access to your files and desktop
→ Plugins bundle Skills with tool connections and slash commands

Anthropic launched 11 plugins on January 30, 2026:

Business Operations:

→ Sales: /call-prep with HubSpot, Salesforce, Clay
→ Marketing: brand voice with Canva, Figma, HubSpot
→ Legal: /review-contract with document stores
→ Finance: /reconciliation with Snowflake, BigQuery, Excel
→ Support: auto-triage with Zendesk, Intercom

Technical:

→ Data: /write-query with Snowflake, BigQuery, Postgres
→ Product Management: /write-spec with Linear, Jira, Notion
→ Enterprise Search: unified search across Email, Slack, Drive, Notion

Specialised:

→ Bio Research: protocol optimisation with PubMed, lab databases
→ Productivity: /update with Slack, Notion, Asana, Jira
→ Plugin Create: describe what you need, Claude builds it

Every plugin is open source. Install, modify, or build your own.

Six Workflows We've Been Testing

Workflow 1: Content Creation with the Marketing Plugin

The Marketing plugin connects Claude to your brand voice, campaign calendars, and content drafts.

Add your own Skills on top: a brand voice Skill with your tone rules, a content format Skill with your post templates.

The workflow:

1. Install the Marketing plugin in Cowork
2. Upload your brand voice Skill
3. Grant Cowork access to your content folder
4. Open Cowork and type: "Draft 5 LinkedIn posts from the notes in my /content-ideas folder. Use my brand voice. Save each as a separate file."

Claude reads your notes, applies your brand voice Skill, follows the Marketing plugin's content structure, and saves five draft posts to your folder.

Queue multiple tasks and Claude runs them in parallel using sub-agents.

Workflow 2: Sales Prep with the Sales Plugin

The Sales plugin connects to HubSpot, Salesforce, Close, Clay, and ZoomInfo. It includes slash commands like /call-prep and /competitive-brief.

The workflow:

1. Install the Sales plugin
2. Add a Skill with your ICP criteria and qualification questions
3. In Cowork, type: "/call-prep for [prospect name]"

Claude pulls the prospect's CRM data, researches their company, scores them against your ICP, and generates a one-page call brief.

Without the ICP Skill, you get a generic brief. With it, Claude flags the talking points that matter for your business.

Workflow 3: Contract Review with the Legal Plugin

The Legal plugin reviews documents and flags risk using a red/yellow/green system. Add a Skill with your company's standard terms and deal-breakers.

The workflow:

1. Install the Legal plugin
2. Grant Cowork access to your contracts folder
3. Type: "/review-contract" and attach the document

Claude reads the full contract, flags risky clauses in red, concerning ones in yellow, acceptable ones in green. Compared against your specific requirements, not generic legal principles.

For NDAs, use /triage-nda instead. Focused on non-compete scope, confidentiality duration, and IP assignment.

Workflow 4: Build Your Own Plugin

The Plugin Create plugin lets you describe what you need in plain language. Claude builds the plugin for you.

The workflow:

1. Open Cowork
2. Type: "Create a plugin for our content team. Include Skills for our brand voice, newsletter format, and LinkedIn post templates. Add slash commands for /draft-newsletter, /linkedin-post, and /content-calendar."
3. Claude generates the full plugin structure
4. Review, edit, and install

You now have a custom plugin your entire team installs. Everyone gets the same Skills, same commands, same output quality.

Workflow 5: Sales Call Into a Client Dashboard

This one combines a Skill and a Plugin in a single workflow:

1. Install the notion-meeting-intelligence Skill to capture next steps from calls into your Notion Knowledge Base
2. Open the data-storytelling plugin and ask Claude to visualise your next steps and proposed automation process for the prospect
3. Share the interactive dashboard with your prospect's team before the next call

You walk into meeting two with a working document, not a slide deck. For enterprise deals with multiple decision makers, this changes the dynamic.

Workflow 6: Visualise, Edit and Draw Anything

Download the Excalidraw plugin: https://github.com/antonpk1/excalidraw-mcp-app

Use Option 1 to install (fastest way).

You visualise frameworks, lead magnets, and diagrams in less than five seconds.

The key insight: you edit in two ways. Click and drag using Excalidraw, or type instructions in the Claude chat interface.

This works with Sonnet 4.5 too. You don't need Opus for the visual workflows.

The Part People Skip

Skills require one thing no AI tool provides: you need to understand your own business.

The processes, the decisions, the tone, the standards. If you don't know what good output looks like for your company, no Skill will fix that.

This is the part people skip. They want the automation before they've defined what to automate.

Build your own skills first. Document how you work. Then teach Claude.

Don't Know Where to Start?

You don't have to build from scratch. Six libraries already have 1,000s of pre-built Skills ready to install.

Installing a Skill takes 30 seconds: download the Skill file (.zip or SKILL.md), go to Settings > Capabilities > Skills, upload the file. Done.

Where to find them:

→ Anthropic's Official Library (github.com/anthropics/skills): Anthropic's own collection. These are the Skills they built internally, including the frontend designer, document creators, and the Skill builder itself. Start here to understand what a well-structured Skill looks like.

→ Partner Skills Directory (claude.com/connectors): Official skills built by Anthropic's partners including Asana, Atlassian, Canva, Figma, Sentry, and Zapier. Vetted integrations designed to work with each company's MCP server.

→ Skills.sh (skills.sh): The most polished community library. Browse by category, preview the Skill before installing, and modify anything. If you only bookmark one library, make it this one.

→ SkillsMP (skillsmp.com): Marketplace-style library with a wide range of community submissions. Stronger on automation and integration Skills.

→ Smithery (smithery.ai/skills): Curated collection with detailed descriptions and ratings. Good for finding niche Skills you wouldn't think to build yourself.

→ SkillHub (skillhub.club): Growing library with a focus on business tools. The website auditor Skill here runs full SEO, technical, and content audits with health scores.

If you're not sure what your business needs, start here. Browse the libraries, install two or three that match your daily tasks, and see what Claude does with them. You'll get ideas for custom Skills faster than starting from a blank page.

For the full technical specification, Anthropic published a 32-page guide: The Complete Guide to Building Skills for Claude.

Stay curious, stay human, and keep creating.

— Charlie