Day 24: Build the one agent your work actually needs.
You’ve watched two of my agents run. Today I build mine in front of you, the one that turns a post into a carousel, then you build yours.
Welcome to Day 24 of the challenge.
This week you’ve watched two agents do real jobs. The morning brief that gathers your day. The industry review that watches your world. Both mine, built to a pattern.
Today you build one that’s yours. And to show you how, I’m going to build mine in front of you: the one I reach for most, the one that turns a post I’ve written into a finished carousel. Then you build yours, the same five parts, for whatever eats your time.
A word before we start
Every agent, however clever it sounds, is the same five parts. The trigger, when it runs. The job, what it does. The context, what it reads to do it well. The output, where the result lands. The guardrail, what it must never do.
Mine takes a post I’ve already written and lays it out as a carousel, on my brand, ready to upload. I write the words. It does the design. That line, my words and its build, is the whole point. The AI doesn’t write in my voice. It frees me from the two hours in Canva.
Pick yours by the groan test. The task you sigh before starting. Repetitive enough to hand over, important enough to want done well. That’s your candidate.
Step by step
Step 1.
Pick your agent. Mine’s the carousel machine. If your groan is a different one, three that suit most people:
The carousel machine. You write a post, it lays it out as an on-brand carousel, slide by slide, ready to upload. Your words, its design.
The inbound drafter. People ask you the same kinds of questions by email or DM. The agent drafts a reply in your voice, filed for you to check and send. It never sends.
The weekly money check. Every Friday it looks at the model you built on Day 19 and flags anything tight, anything overdue, anything worth chasing.
Pick the one that makes you groan the loudest. I’ll build the carousel machine here, and the shape works for any of them.
Step 2.
Open Cowork in your desktop app, pointed at your Switched-On folder. Opus for this one.
Step 3.
Build it and test it on something real. Here’s the exact prompt I used. Swap the job for yours and the shape holds:
I want to build an agent that turns a post I’ve written into a finished, on-brand carousel. Let’s build it the five-part way and test it on a real post now.
First read my brand files in this folder, my colours, fonts and wordmark, so it comes out on brand.
The spec:
Trigger: I run it whenever I’ve written a post I want as a carousel.
Job: take my post exactly as written, find the natural slide breaks (slide 1 the hook, one idea per slide, the payoff near the end, a simple call to action last), and design each slide.
Context: my brand files and the post. My words, my brand.
Output: build it as one HTML file with each slide at 1080 x 1350, then save every slide as its own numbered image (01, 02, 03) in a new folder so they upload in order.
Guardrail: do not change or rewrite my words, lay them out only. If a line is too long for a slide, tell me and let me cut it myself. Never invent a stat or a quote.
Here’s the post: [paste your post]. Build it, then show me the slides.
Step 4.
Run it by hand first. Same rule as the others. Watch it work in front of you before you trust it. When it flags “this line’s too long for slide 3, want to cut it?” instead of quietly rewriting you, that’s the guardrail doing its job. Tweak until the slides are the ones you’d actually post.
Step 5.
Save it as a one-tap job.
That’s the one. Save it as a reusable agent in a file called carousel-machine.md in this folder, with the full five-part spec, so next time I can say “run the carousel machine on this post” and paste a new one.
One line from now on: “run the carousel machine on this post”.
Step 6.
Lock it in.
Add to MEMORY.md: Day 24, built my own agent, the carousel machine. The pattern is five parts: trigger, job, context, output, guardrail. I write the words, it does the build. I can make these myself now.
A safety note
Your own agent will be closer to your real work, so the leash matters more, not less.
It builds, it never posts. Nothing goes public, gets sent, spent or deleted without you. For the carousel machine that means it makes the slides and stops. You’re the one who hits upload. Those words go in the guardrail and stay there. And know how to switch it off before you switch it on.
What you’ll notice
The quiet click of “I can build these”. Up to now you ran agents I designed. Today you designed one. That’s the line between using AI and directing it, and you just crossed it. And in the carousel’s case, the two hours in Canva, gone, with your words still your own.
Why this works
Once you’ve seen the five parts twice, the third is only filling them in for your own life. The pattern is the skill. Any single agent is just one use of it. And there’s no ceiling on it: the same five parts that build a one-tap carousel can build a whole app. You keep the pattern forever, long after these particular jobs change.
Key takeaway
Three agents now, and the third is yours. You do not need me to build the next one. You have the recipe.
Where this is heading
Tomorrow, the quiet payoff of building this folder all month. You get to talk to it.
Tomorrow on Switched On
Day 25: Talk to your second brain.
Three weeks of files in one folder. Point Claude at all of it and ask the questions only someone who knows you could answer.
Nishma x
P.S. How did today land? Three buttons, thirty seconds. Tap here
I read every response. The data shapes the rest of the challenge.
Catching up? Days 0 to 23 are on the Switched On Substack archive HERE.
Got a friend or a colleague who this might be useful for? Send her to nishma.co/30daychallenge
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