Build Your Own Skill
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A hands-on walkthrough of writing your own skill from scratch - a plain-English markdown file that encodes a workflow you do every week, so Cowork runs it the same way every time.
Core Concept
You already installed a skill in 2.2. This chapter is where you flip the relationship - you start building your own. It's the move that separates casual Cowork users from people who get real leverage out of it. The moment you can teach Cowork your workflow, your way, you stop being a user and become an operator.
No code, no terminal, no setup. If you can write an email, you can build a skill.
How It Works (Step-by-Step)
Step 1 - Recognize when a task should be a skill
Three signals.
- Every week. You do this task on a recurring cadence.
- Same way. The steps don't change.
- Same shape. The output has a consistent format.
Friday client updates. Monday meeting prep. The weekly KPI summary. The way you triage your inbox. These aren't creative tasks - they're patterns. Patterns are what skills are for.
Step 2 - Understand the anatomy
Every skill has three parts.
- Name - what you call it (weekly-client-update).
- When-to-use - a sentence that tells Cowork when this skill should fire ("use this when the user asks me to draft the Friday recap for a client").
- Instructions - the actual steps, in plain English, in the order you want them done.
That's the whole thing. If you've ever written a checklist or an SOP, you've already done the hard part.
Step 3 - Write a first skill
Pick one task you do every week the same way. Write it as a markdown file with YAML frontmatter for the name and description, then the body as your instructions.
A minimal example - a Friday client update skill:
---
name: weekly-client-update
description: Draft a Friday client update email. Use when Cameron asks for the weekly recap for a specific client.
---
You are drafting Cameron's weekly client update email.
Steps:
1. Pull the client's project folder from Drive.
2. Find what shipped this week (files updated, decks changed).
3. List 2-3 things in progress.
4. List anything blocked and what's needed to unblock.
5. End with one question for the client.
Format:
- Subject: "Weekly update - [Client name] - [Friday date]"
- Warm but businesslike. Not corporate.
- Under 200 words.
- Sign off: "Talk Monday - Cameron"
Do not:
- Send the email. Always leave it as a draft.
- Pad with "great week" filler.
Step 4 - Install it
Settings → Skills → Add. Point at your .md file. Cowork picks it up. From that moment on, when you trigger the skill's phrasing, Cowork follows the instructions exactly, every time.
Step 5 - Iterate
Your first version of a skill will be wrong in small ways. Use it, see what missed, edit the file, run it again. Three iterations and you'll have something you trust for the next year.
Why This Matters
Custom skills are the multiplier on everything else in this course. A connector without a skill is a doorway with no one walking through it. A schedule without a skill runs but doesn't know what to do. Everything in Section 5 leans on the muscle you build here.
What Should Be Possible After This
- Identify a task in your own work that fits all three skill signals.
- Write a SKILL.md with name, description, and instructions.
- Install it into Cowork.
- Iterate on it based on real use.
Your first skill exercise
- Pick one task you do every week, the same way.
- Write a skill for it - three parts, name, when-to-use, instructions.
- Drop it in your skills folder.
- Trigger it once on a real example.
- Tweak the instructions wherever it missed.
By the time you've iterated twice, you've built something you'll use for the next year.
1. Which three parts does every skill have according to the chapter content?
2. Why is it important to iterate on your skill after you first install and use it in Cowork?
Thanks for your feedback!
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Build Your Own Skill
A hands-on walkthrough of writing your own skill from scratch - a plain-English markdown file that encodes a workflow you do every week, so Cowork runs it the same way every time.
Core Concept
You already installed a skill in 2.2. This chapter is where you flip the relationship - you start building your own. It's the move that separates casual Cowork users from people who get real leverage out of it. The moment you can teach Cowork your workflow, your way, you stop being a user and become an operator.
No code, no terminal, no setup. If you can write an email, you can build a skill.
How It Works (Step-by-Step)
Step 1 - Recognize when a task should be a skill
Three signals.
- Every week. You do this task on a recurring cadence.
- Same way. The steps don't change.
- Same shape. The output has a consistent format.
Friday client updates. Monday meeting prep. The weekly KPI summary. The way you triage your inbox. These aren't creative tasks - they're patterns. Patterns are what skills are for.
Step 2 - Understand the anatomy
Every skill has three parts.
- Name - what you call it (weekly-client-update).
- When-to-use - a sentence that tells Cowork when this skill should fire ("use this when the user asks me to draft the Friday recap for a client").
- Instructions - the actual steps, in plain English, in the order you want them done.
That's the whole thing. If you've ever written a checklist or an SOP, you've already done the hard part.
Step 3 - Write a first skill
Pick one task you do every week the same way. Write it as a markdown file with YAML frontmatter for the name and description, then the body as your instructions.
A minimal example - a Friday client update skill:
---
name: weekly-client-update
description: Draft a Friday client update email. Use when Cameron asks for the weekly recap for a specific client.
---
You are drafting Cameron's weekly client update email.
Steps:
1. Pull the client's project folder from Drive.
2. Find what shipped this week (files updated, decks changed).
3. List 2-3 things in progress.
4. List anything blocked and what's needed to unblock.
5. End with one question for the client.
Format:
- Subject: "Weekly update - [Client name] - [Friday date]"
- Warm but businesslike. Not corporate.
- Under 200 words.
- Sign off: "Talk Monday - Cameron"
Do not:
- Send the email. Always leave it as a draft.
- Pad with "great week" filler.
Step 4 - Install it
Settings → Skills → Add. Point at your .md file. Cowork picks it up. From that moment on, when you trigger the skill's phrasing, Cowork follows the instructions exactly, every time.
Step 5 - Iterate
Your first version of a skill will be wrong in small ways. Use it, see what missed, edit the file, run it again. Three iterations and you'll have something you trust for the next year.
Why This Matters
Custom skills are the multiplier on everything else in this course. A connector without a skill is a doorway with no one walking through it. A schedule without a skill runs but doesn't know what to do. Everything in Section 5 leans on the muscle you build here.
What Should Be Possible After This
- Identify a task in your own work that fits all three skill signals.
- Write a SKILL.md with name, description, and instructions.
- Install it into Cowork.
- Iterate on it based on real use.
Your first skill exercise
- Pick one task you do every week, the same way.
- Write a skill for it - three parts, name, when-to-use, instructions.
- Drop it in your skills folder.
- Trigger it once on a real example.
- Tweak the instructions wherever it missed.
By the time you've iterated twice, you've built something you'll use for the next year.
Thanks for your feedback!
