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The prompt that stops a builder making the wrong app

How do you describe an app to an AI builder so it builds what you actually wanted?

Last checked 2026-09-24

Describe who uses it, the single thing they came to do, and what happens when that goes wrong. Builders fill silence with assumptions, and the assumptions are always generic. Three sentences of specificity at the start saves rebuilding the whole thing on day two.

The prompt

Before building, confirm back to me: who uses this, the one thing they come here to do, what data it stores, and what should happen when something goes wrong. If any of that is unclear, ask me instead of assuming.

When to use itThe first message of any new project, before a single screen exists.
Why it is worded that wayA browser builder will produce something plausible from almost nothing, which is exactly the problem: you get a generic app with a dashboard you did not ask for and a signup flow you did not need. Making it repeat the brief back surfaces the assumptions while they are still free to change.

The question that saves the most rework

"What should happen when something goes wrong?" Almost nobody specifies this, so builders produce apps with no error states at all — which looks fine in a demo and falls apart the first time a real person mistypes something.

One thing, not five

Naming a single primary action produces a focused app. Listing five produces a menu. You can add the other four later, against something that already works, and they will fit better for it.

Say what it must not do

Builders add features generously — accounts, notifications, a dashboard. If you do not want those yet, say so, because removing them afterwards is harder than not having them.

The Build Prompt Pack

This is one of 57 prompts, from the phase "Start without it building the wrong thing". The pack has the rest, each with the same reasoning underneath, plus the research they are built on and a house-rules file you paste in once.

Get the pack — €9

Tools this applies to

ToolWhat it doesPrice
LovableBuilds complete apps from a prompt. The most finished output of the group.Free tier, then ~$25/mo
BoltFast full-stack prototypes, entirely in the browser.Free tier, Pro ~$25/mo
v0Strong on how individual screens look; now full apps too.Free tier, then ~$20/mo
ReplitBuilding and hosting in one place, agent included.Free tier, Core ~$20/mo
Base44The most guided, genuinely no-code experience of the group.~$20/mo

Every tool has its own page with what it costs and who should skip it. Some links are affiliate links.

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The whole library

All prompts →The packs →