For Cursor users

What to build on Cursor. Decide in 20 minutes.

Cursor is a VS Code fork with an AI agent that reads your whole repository, edits across files and runs your tests. What it can't tell you is whether the thing is worth building. Nine forced decisions against live G2 and Reddit data, then a Cursor-optimised spec carrying your buyer, scope, price and launch plan straight into .cursorrules.

$5 Quick Take · No credit card · 9 decisions in 20 minutes

Stage 9 · The export

What you paste into .cursorrules

A project rules file, .cursorrules or its modern equivalent, that Cursor loads into every chat automatically. It carries the buyer, the V1 boundary and the pricing tier, so the agent has a reason to push back when a request falls outside the release rather than cheerfully implementing it. The example below uses a freelance-accountant idea; yours will be specific to your own.

cursor.com

Pasted into .cursorrules · ShipFit Quick Take · $5

## Buyer

Sarah, 38, freelance accountant in the UK. Earns £80k/yr. Willing to pay £29/mo for tools that save admin time. Decision timeline 7 days. Channels: r/accounting, AccountingWEB.

## Problem (severity 9/10 from G2 + Reddit)

Client onboarding takes 4-6 hours per new client. Manual data entry, duplicated forms, chasing missing documents.

## V1 scope — Lean package (2-week build)

✓ Smart intake form with VAT-number prefill ✓ Document upload with auto-categorisation ✓ Welcome email sequence with checklist ✓ Single-page dashboard showing new-client pipeline ✗ Multi-user access (Balanced package only) ✗ Stripe integration (post-MVP)

## Stack

Next.js 14, Supabase auth + Postgres, Tailwind. Deploy via the host platform.

## Pricing (Van Westendorp: £19-£39, optimal £29)

Free: 1 active client · Pro: £29/mo, 10 clients · Agency: £79/mo, unlimited

## Launch (channel-matched to buyer)

Week 1: r/accounting AMA + AccountingWEB guest post. Week 2: AccountingWEB ad burst + cold email to 50 firms. Success metric: First paying customer in week 4.

## Tone of voice

Crisp, professional, no fluff. UK English. Sarah is time-poor.

Generated from 9 forced decisions · Sourced from live G2 + Reddit

▶ Open in Cursor

The failure mode

On Cursor, productive and useful are not the same thing

Cursor is at its best on code that already exists. It refactors well, names things well, writes the tests you have been avoiding and untangles the module you have been ignoring since March. Every one of those sessions feels excellent.

None of them is evidence. The characteristic Cursor failure is not a mess, it is the opposite: a genuinely well-maintained codebase, six weeks in, serving a product whose buyer has never been identified. The work was real, the quality was real, and the direction was never checked because nothing in an editor checks direction.

The tool rewards the part of the job you are already comfortable with. That is worth knowing about it.

637

ideas put through the sequence since October 2025. 2,888 problems surfaced and ranked.

named frameworks applied at the right stage. Christensen, Fitzpatrick, Vohra, Helmer.

Live

signal from G2, Trustpilot, Reddit, App Store. Real complaints, not generated text.

Quick Take. No credit card. Full 9-stage playbook from $10.

How it works

From idea to Cursor spec in 20 minutes

9 stages, in order, each one building on the last. Skip one and the next breaks. At the end, the Cursor-optimised export pastes into .cursorrules.

Q1Worth Building?

Ship / Pivot / Kill verdict

Q2Who Pays?

Named buyer + willingness-to-pay

Q3What Hurts?

Pain ranked from G2 + Reddit

Q4How to Win?

Positioning vs real competitors

Q5What's V1?

Lean / Balanced / Full scope

Q6How to Charge?

Van Westendorp pricing tier

Q7Will They Pay?

Landing copy + traffic plan

Q8How to Launch?

Channel-matched playbook

Q9What to Export?

Tool-optimised prompt

Paste into Cursor. Build.

Same tool, different brief

What changes in .cursorrules

Cursor is the same tool either way. The difference is entirely in what it has been told.

Without the spec

Refactors happily for six weeks, because refactoring is always available.

With it

Has a release boundary to compare a request against, and a reason to say not yet.

Without the spec

Treats every file in the repo as equally load-bearing.

With it

Knows which features serve the ranked problems and which were an afternoon's enthusiasm.

Without the spec

Loses your validated context the moment you stop @-mentioning the doc.

With it

Loads it on every chat, automatically, for the life of the project.

Honest questions

The stuff Cursor builders actually ask before paying $5.

Frequently asked questions

Can't I just describe my idea to Cursor directly?

You can, and Cursor will build it. The problem is Cursor will build anything. It doesn't tell you the idea has no buyer, the pricing is wrong, the scope is bloated or the launch channel for this audience is paid not organic. ShipFit decides those nine things first so Cursor builds the right thing, not just the next thing.

Do I still need my Cursor subscription?

Yes. ShipFit isn't a builder. It's the step before. ShipFit decides what to build. Cursor builds it. The two are complementary, not competing. ShipFit's stage-9 export drops straight into .cursorrules.

How is this different from putting my validation notes in a /docs folder?

Cursor never reads /docs/validation.md unless you @-mention it, and you will mention it for about a week. Project rules load on every chat for the life of the project, without anyone remembering to do anything. Same words, very different effect on the model.

I'm working on an existing codebase, not a new project. Does this still apply?

It applies more. A greenfield project has no sunk cost, so changing direction is cheap. An existing codebase has months of good work in it, which is exactly the thing that makes founders reluctant to ask whether the direction is right. Run the nine decisions against what you have.

Will this stop Cursor doing the refactoring I actually want?

No. The rules describe the product, not your engineering conventions, and you add those on top. Re-running stage 9 refreshes the product half without touching the conventions you wrote.

What happens if the verdict goes against my idea?

You saved a Cursor build cycle, which is the feature rather than the bug. The Quick Take verdict arrives with a Why: which of the nine decisions broke down, whether that was the buyer, the pricing room or the differentiation. You either iterate on the idea or pick a stronger one. Either way, $5 buys a forced conversation with the data before you spend three months building.

Get my Cursor spec

$5 Quick Take. 2 minutes. Live data. Real verdict. Or $10 for the full 9-stage playbook with the Cursor-optimised export.