Before You Build
Not because it's bad at code. Because you described a feature in a sentence, it disappeared for forty minutes, and there was no point in between where you could see the plan while changing it was still free. This fixes the in-between.
What you get instead
You ask for a feature. Before writing a line, your agent hands back one page: the screen as it works today and as it would work after, both running as mocks you can actually tap. Where the change sits in the rest of your app. What it won't do. The strongest argument against building it at all. And the checks that settle whether it worked.
Two minutes to read. Then you either say go, or you fix the plan while fixing it costs nothing.
Plenty of free tools will make your agent write a spec first. They all write it for an engineer. The difference here is who the page is for — the person paying for the work, who has never once been able to check a plan before it was built.
This is a real page for a real feature in a travel app: three cities need a hotel, and today you can only search for one at a time. Both mocks work. Tap them, close the window mid-search, see what happens.
Open the exampleThat page is free and it stays free. It's also the honest sample of what the kit produces, which is why it's here rather than behind the payment — nothing here is refundable, so you should find out what you're getting first.
The shop
Files you download and install. Work I do for you. Or a membership if you'd rather the kits stayed current as the models change underneath them.
Markdown and one small script. Works with Claude Code out of the box, and as a plain prompt in anything else.
You send the feature. I send back the page.
Where this came from
I run five software projects with coding agents. Last month I measured where my file changes actually landed, expecting to feel good about it. Eighteen percent reached anywhere a customer could get to. Half went into my own tooling. The flagship — the one thing meant to earn money — got three percent.
The agent bill for that month was about two thousand dollars a week. A good chunk of it went on long confident runs that produced the wrong feature, which I only found out by reading the diff afterwards.
So I started making the agent show me a page first. The page above is one of them. The first time I opened one I killed the expensive half of the feature before it was written, because the page's own case-against section pointed out that the cheap half fixed the whole complaint. That's what's for sale.
These are instruction files. A good model with a clear prompt will produce something in this direction on its own, and if you enjoy writing prompts you can probably get most of the way there in an afternoon. What you're paying for is that the afternoon is already spent, and for the specific bits that aren't obvious — the case-against section, the rule about not mocking something prettier than you can build, and the two-minute limit that stops the habit dying in a fortnight.
If you're building alone and you're happy with what your agent gives you, you probably don't need this yet. Come back when a run costs you a day.
Questions
It installs as a skill in Claude Code, which is the tidiest way to run it. The files themselves are markdown with no tool-specific machinery in them, so pasting one in front of a request works the same in Cursor, Codex, or a chat window. The install notes cover both.
One-off purchases are the version you bought. Your download link is good for a week; reply to the receipt any time after that and I'll send a fresh one. If you want the files kept current as models change, that's what the membership is.
The free tools — Spec Kit, Kiro, the one built into your editor — write specs for engineers to read. This writes a page for the person who can't read a diff: your co-founder, your client, whoever actually decides. If everyone reviewing your work reads code, use the free ones. If someone doesn't, they have never been able to check your plans and this is the fix.
Because one agent run that builds the wrong feature costs more than that in tokens alone, before your time. Whether it's worth it to you is worth deciding before you pay, because there are no refunds.
No. Everything here is final sale — the files arrive the second you pay, so there's nothing to hand back. That's why the example is free and complete: open it, click both mocks, and find out whether you want this before any money moves. If a made-for-you page misses, tell me what's wrong and I'll fix it. The round of changes is included; the money stays put. The terms say all of this in full.
A description of the feature in whatever words you have, and either a link to the product or a few screenshots of the screen that changes. If it's not public, screenshots are plenty — I don't need your code.
One person, building software products with agents, in public. You'll get replies from me and not a help desk. That's the good and the bad of it.