Free tool · no sign-up
Coding agents don't fail because they can't write the code. They fail because they had to guess what you wanted, and guessed. Answer nine questions and get one short file that leaves nothing to guess.
takes about
Five minutes. Nothing you type is sent to us: the file is built in your browser, and the draft is saved on this device only.
A working name is fine. It names the file.
Finish the sentence "Marginal is…". If it needs two sentences, it's two products.
One kind of person. "Everyone" is how you get an app for nobody.
The bad workaround. If there isn't one, nobody has this problem yet.
One per line, each starting with a verb. Three to six lines. If you have twelve, you're describing v3.
The section everyone skips and the one that changes the result most. Every line here is a feature you won't have to delete later.
One kind of record per line, with its fields. Usually there are one or two, not eight.
Two answers agents invent more often than any others. Saying it here stops billing appearing in a free app, stops a paid one shipping wide open, and stops accounts being built for something nobody signs in to.
One walkthrough you could do yourself. That's the finish line, and it's also the first test.
Paste this into your coding agent, or save it as the first file in your repo and point the agent at it.
01 / why this shape
Long briefs feel thorough and mostly produce features nobody asked for. The shape below is the one that survives contact with an agent.
Say what it is not
An agent handed a gap fills it from its own assumptions, and it does that silently. The question about what v1 leaves out is the highest-value line in the file: it is the one that stops you deleting code you never wanted.
Name the finish line
"Done" as a walkthrough you could perform yourself is checkable. "Done" as a feeling is a conversation you will have four times.
Leave the plumbing out
Nothing in this file describes sign-in, payments, email or deploys. Those are the same in every app, and re-specifying them is how a session gets spent on the part that is not yours.
Keep it one file
It goes in the repo, next to the code. An agent reads it every session, and you edit it when the answer changes instead of re-explaining in chat.
Hand your coding agent a foundation that already works, and go from idea to a prototype in one shot.