Przemysław Zalewski

Agent skill · idea validation

Score your business idea before you build it

Ask a chatbot about your idea and it will love it. This skill scores the idea on ten rubrics, from 1 to 5, quotes your own words as evidence and applies a verdict rule written in code: Build, Validate first, Pivot or Stop. Then it names the riskiest assumption and up to three cheap experiments.

Add to Claude Use in ChatGPT Source on GitHub

/business-idea-validator · Version 0.1.0, updated · free, MIT · Works in Claude Code, claude.ai, ChatGPT, Codex

Why a rule instead of an opinion

The usual failure is months of building and learning in the first week of sales that nobody pays. An honest score before the first line of code costs less than an MVP.

Language models are agreeable, so the skill takes the mood out. Each rubric has fixed scoring anchors, every score needs a quote from your description and a confidence level, and the verdict comes from a rule in scripts/verdict.mjs that you can read and check by hand. A critic pass tries to refute the extreme scores.

How it works

  1. 1

    Describe the idea

    A paragraph or a file: who has the problem, what you sell, the price, how they will find you.

  2. 2

    Ten rubrics, scored

    Problem, customer, market, alternatives, monetization, distribution, feasibility, defensibility, founder fit and risks. Each from 1 to 5, with a quote and a confidence level.

  3. 3

    A verdict by rule

    Build, Validate first, Pivot or Stop, computed from the scores, never from the mood.

  4. 4

    Next steps with numbers

    The riskiest assumption, up to three experiments with pass and fail thresholds, and open questions. Markdown and JSON, in English or Polish.

What it looks like

Shortened. Example input and output.

Claude Code
/business-idea-validator A booking app for dog groomers, 19 EUR a month
Verdict: Validate first
Strongest: Problem 4/5, “groomers lose bookings to missed calls”
Weakest: Distribution 2/5, no channel to reach groomers is named
Riskiest assumption: groomers pay 19 EUR a month instead of using a free booking link
Experiment 1: call 20 groomers. Pass: 5 agree to a paid pilot. Fail: fewer than 2.

What you get

  • The riskiest assumption and up to three experiments with pass and fail numbers.
  • Markdown and JSON, in English or Polish.
  • The verdict rule is code, so you can check it by hand.

Try it without installing

The same rubrics and the same verdict rule run online. Paste an idea and see the report in a minute.

Who it is for

  • Founders before an MVP.
  • Side projects competing for your evenings.
  • Agencies and consultants who screen client ideas.

Who it is not for

  • Market research reports, pitch decks or financial models.
  • Skipping customer conversations. It tells you which conversation to have first.

Install

Pick the place you already work in. Every option installs the same open-source skill. Needs an agent that can read files and run Node 20 or later for the report check. Subagents are optional; claude.ai runs the rubric passes inline.

Claude Code

Inside a session: add the marketplace, install the pack, reload. The pack also brings the other skills.

in a Claude Code session
/plugin marketplace add Ciunkos/skills
/plugin install ciunkos@ciunkos
/reload-plugins
then
/business-idea-validator A booking app for dog groomers, 19 EUR a month

Codex

Clone the repository and symlink the skill into ~/.agents/skills. Start a new session and call it with $business-idea-validator.

terminal
git clone https://github.com/Ciunkos/skills ~/ciunkos-skills
mkdir -p ~/.agents/skills
ln -s ~/ciunkos-skills/skills/business-idea-validator ~/.agents/skills/business-idea-validator

Browse the code · Releases and changes · Update

Done for you

The verdict says Build?

Then the next step is a first version that can take money. I build MVPs with AI agents and turn them into products people pay for, for a fee or as a business partner.

Get the next skill by email

One short email when a new skill ships or one changes a lot. No newsletter, no sales sequence.

Done. You are on the list. Every email has a one-click unsubscribe.

I keep your address until you unsubscribe, use it only for these emails and share it with no one. It is stored on Cloudflare. Every email has a one-click unsubscribe. Questions or removal: ciunkos@gmail.com. Controller: Przemysław Zalewski, company details in the footer. Prefer GitHub? Watch, Custom, Releases

FAQ

Questions

Can I trust the verdict?
Treat it as a starting point. The rule is fixed and every score has a quote, so you can see exactly why it said Pivot and argue with the evidence, not the mood.
Do I have to install it to try?
No. The online version runs the same rubrics in the browser.
Where does my idea go?
Into your own agent session. The skill makes no network calls; the report stays on your computer.
Does it work in Polish?
Yes. The report comes in English or Polish, and you can describe the idea in either.

Let’s find out in 30 minutes

A free 30-minute call. You bring the problem, I bring questions. Want a number first? The configurator shows hours, a price range and the start date.

If I am the wrong person I will say so on the call and point you to someone better.

Book a free 30-min call Email me instead

or write to ciunkos@gmail.com

After you book: a calendar invite, then the call, then the scope in writing within 24 hours. Nothing else to fill in.

My pledge

  • Reply within 24 hours. I reply within 24 hours on working days, personally, not a bot. Weekend messages: by Monday noon.
  • Late means free. If I am late, the first hour of work is free. You do not have to ask.
  • Scope in writing within 24 hours. A free 30-minute call with no company deck, then the scope and the price in writing within 24 hours. You decide.
  • The person who does the work. You talk to the person who does the work. No sales layer, no handoff.
  • Follow-up only with news. I follow up only when I have something new for you. Never a "did you see my offer".
  • Honest "not a fit". If I am not the right person, I say so on the call and point you to someone who is.

Calls this week · work starts 2 November 2026 · B2B contract or employment · Wrocław, Poland (CET), remote