Create Low-Cost MVPs | Prompt Consulting

The biggest mistake early-stage founders make is building before they validate. Months of development, thousands of dollars, and enormous emotional investment go into a product — only to discover that the core assumption was wrong. An MVP is not a small version of the full product. It is the fastest, cheapest test of the one belief your entire business depends on. This prompt helps you design that test correctly: identify the critical assumption, choose the right MVP format, and build the minimum possible version that will give you a real answer.

What It Does

Identifies the single most critical assumption your business depends on and designs an MVP specifically built to test that assumption — not the whole product.
Recommends the lowest-cost, fastest MVP format for your specific business model, whether that is a landing page, concierge MVP, wizard-of-oz test, prototype, or pre-sale campaign.
Produces a launch checklist with success criteria so you know in advance what a passing result looks like and what a failing result means.

The Prompt

#CONTEXT:
I am building a new product or business and I want to validate my core idea before investing significant time or money in development. I need help designing a low-cost, fast MVP that tests whether my primary assumption is true. The MVP should tell me whether real people have the problem I think they have, whether they want the solution I am planning, and whether they will pay for it — without requiring me to build the full product first.

#ROLE:
You are a lean startup advisor who has guided over 100 early-stage founders through idea validation. You understand that most startup failures come from building before validating, and you are skilled at cutting through feature lists to find the single critical assumption that determines whether a business works. You know every low-cost MVP format and when to use each one based on the business model, target audience, and the specific assumption being tested.

#RESPONSE GUIDELINES:
1. Identify my single most critical assumption — the one belief, if false, that would make the entire business unviable.
2. Recommend the best MVP format for my situation and explain why that format tests the critical assumption better than the alternatives.
3. Provide a step-by-step build plan for the MVP with a realistic timeline and cost estimate.
4. Define clear success and failure criteria so I know exactly what result would validate or invalidate my assumption.
5. List the top 3 risks of my current approach and how to mitigate each one.

#MVP DESIGN CRITERIA:
1. The MVP must test the critical assumption directly — not a proxy or a nice-to-have feature.
2. Time to first learning must be under 4 weeks for a digital product, under 8 weeks for a physical product.
3. Total cost must be achievable with under $500 for digital MVPs unless there is a compelling reason otherwise.
4. The MVP must involve real customers taking a real action — not just saying they would use the product.
5. Define a minimum number of positive signals (sign-ups, payments, interviews with confirmed pain) required to proceed to the next stage.

#INFORMATION ABOUT ME:
- My business idea: [IDEA — describe the product/service and the problem it solves]
- My target customer: [CUSTOMER — be specific: who they are, what they do, what they currently do instead of using my product]
- My primary revenue model: [REVENUE — e.g., subscription, one-time purchase, marketplace commission]
- My resources: [RESOURCES — time per week, available budget, technical skills]
- What I have already validated (if anything): [EXISTING VALIDATION — e.g., "10 interviews", "a waitlist of 50", "nothing yet"]

#RESPONSE FORMAT:
Critical Assumption:
[One sentence stating the assumption to be tested]

Recommended MVP Format:
[Format name and why it fits this situation]

Build Plan:
Week 1: [Activity]
Week 2: [Activity]
Week 3: [Activity]
Week 4: [Activity]

Estimated Cost Breakdown:
- [Item]: $[amount]
- Total: $[total]

Success Criteria (proceed to build):
- [Criterion 1]
- [Criterion 2]

Failure Criteria (pivot or kill):
- [Criterion 1]

Top 3 Risks and Mitigations:
1. [Risk]: [Mitigation]
2. [Risk]: [Mitigation]
3. [Risk]: [Mitigation]

How to Use

Describe your business idea in plain language — what it does and the specific problem it solves for a specific type of person. Vague descriptions produce generic MVP advice.
Be honest about your resources. A "build in a weekend" MVP is very different from a "4-week part-time" MVP. The prompt calibrates the plan to what you can actually execute.
After getting your MVP plan, run a secondary prompt asking the AI to roleplay as a skeptical early customer and poke holes in your critical assumption before you build anything.
Set your success criteria before you run the MVP — not after. Post-hoc success criteria are how founders talk themselves into continuing with failed experiments.

Example Input

## Information about me

- My business idea: A subscription service that delivers pre-portioned, dietitian-curated meal prep kits specifically designed for people managing type 2 diabetes — not just low-carb, but medically calibrated macros with glycemic impact ratings on every ingredient
- My target customer: Adults aged 40–65 with type 2 diabetes who cook at home, are frustrated by generic meal prep services that do not account for blood sugar management, and currently spend hours researching and adjusting recipes themselves
- My primary revenue model: Monthly subscription, $89/month for 4 meals per week
- My resources: 10 hours/week, $300 budget, no technical background but comfortable with no-code tools
- What I have already validated: I have had 5 conversations with people in a diabetes support Facebook group who expressed frustration with existing meal kit services

Tips

The concierge MVP is underrated. Instead of building a product, manually deliver the service for your first 10 customers. You will learn more in two weeks of doing it by hand than in two months of building automation for it.
A landing page with a paid sign-up is more valuable than 1,000 email opt-ins. Anyone can say they are interested. Payment is the only signal that eliminates social desirability bias.
Interview before you build anything. Even 5 in-depth conversations with your target customer will change your MVP design significantly. Do these before you spend any money.
Treat the MVP as a science experiment. Define your hypothesis, your test, and your measurement method before you run it — the same discipline that makes scientific experiments valid makes MVP tests valid.
The goal is to be wrong as fast as possible. Finding out your assumption is wrong with a $300 MVP is not a failure. It is a $300 education that saves you from a $50,000 mistake.