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★ From napkin to build plan

Idea → MVP Spec Generator

Describe your idea in a paragraph. Get user stories, a must / should / won't feature board, a data model sketch, risks to test and a 6-week build plan.

  • AI-powered, nothing stored
  • No signup
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Takes 10–30 seconds. Nothing is stored.

01

What a good MVP spec contains

A spec is a list of decisions, not a wish list. The useful ones answer five questions before anyone writes code: who exactly is the first user, which problem hurts enough to pay for, what is the smallest product that solves it, what data it needs, and what you must learn in the first weeks.

Parts of an MVP spec
PartThe question it answers
Target userWho will use this in week one, specifically enough to find ten of them
Feature boardWhat ships now, what's next, and what you are deliberately saying no to
User flowsThe few paths that must work end to end
Data modelThe nouns of the product and how they relate
RisksWhat could make this fail, and the cheapest way to find out early
PlanA week-by-week order of work that ends with real users
02

The MoSCoW method

MoSCoW sorts features into Must, Should, Could and Won't. This tool folds “could” into “won't (yet)” on purpose: in a six-week MVP, maybe means no.

A feature is a must only if the product is pointless without it. It's a should if users would notice and complain, but could still get value. Everything else waits, and writing it down stops it creeping back into the sprint.

03

An example spec

Here's the format, written by hand for this idea: “Freelance designers lose hours chasing invoices. A simple tool that turns a finished project into an invoice, sends polite automatic reminders and shows who owes what.”

Example

Invoicing and polite payment reminders for freelance designers.

For
Solo freelance designers billing 3 to 15 clients a month, currently invoicing from a doc or spreadsheet.
Problem
Getting paid takes longer than doing the work. Designers forget to follow up, or feel awkward doing it, so invoices sit unpaid for weeks.
Success looks like
10 designers send at least 3 invoices each and get 70% of them paid by the due date + 10 days, within 6 weeks of launch.

Feature board

Must have

5

  • Create an invoice in under a minute

    The core job. Line items, tax, due date, a branded PDF.

  • Automatic reminders

    The reason to switch: friendly emails at due date, +3 and +10 days.

  • Card and UPI payment link

    Paying in one click removes the last excuse to delay.

  • Who-owes-what dashboard

    One screen answering 'how much am I waiting on?'.

  • Email sign-up and login

    Needed to keep clients and invoices private.

Should have

3

  • Client list

    Reuse details instead of retyping them every time.

  • Recurring invoices for retainers

    Common for designers on monthly retainers, but not needed day one.

  • Simple landing page

    Somewhere to send the first users and collect a waitlist.

Won't have (yet)

3

  • Accounting integrations

    Users will ask for them; manual CSV export covers v1.

  • Teams and agencies

    Different buyer with different needs. Win solo freelancers first.

  • Mobile app

    A responsive web app is enough for a task done at a desk.

Core user flows

First invoice

  1. 1Sign up with email
  2. 2Add a client
  3. 3Add line items and due date
  4. 4Preview and send

Getting paid

  1. 1Client opens the email
  2. 2Clicks the payment link
  3. 3Pays by card or UPI
  4. 4Invoice marked paid

Chasing a late payment

  1. 1Due date passes
  2. 2Reminder sends automatically
  3. 3Designer sees status on dashboard

Data model sketch

User

  • · email: string
  • · businessName: string
  • · currency: string
  • · logoUrl: string

has many Clients · has many Invoices

Client

  • · name: string
  • · email: string
  • · company: string?

has many Invoices

Invoice

  • · number: string
  • · status: draft|sent|paid|overdue
  • · dueDate: date
  • · total: decimal

has many LineItems · has many Reminders

LineItem

  • · description: string
  • · quantity: number
  • · unitPrice: decimal

Reminder

  • · sendAt: datetime
  • · sentAt: datetime?
  • · kind: due|followup

Risks to test first

Designers may not trust a tool to email their clients for them.

Test it: Show every reminder before it goes out for the first two weeks; measure how many get edited.

Payment fees may feel too high for small invoices.

Test it: Interview 10 designers about fees before choosing a provider; offer bank transfer details as a free option.

Reminder emails land in spam.

Test it: Send from a verified domain with proper SPF/DKIM from day one; track open rates.

6-week build plan

  1. Week 1

    Foundations and sign-up

    • – Repo, CI and hosting
    • – Email auth
    • – Database schema
  2. Week 2

    Create and send invoices

    • – Invoice editor
    • – PDF generation
    • – Send by email
  3. Week 3

    Get paid online

    • – Payment links
    • – Webhook marks invoice paid
  4. Week 4

    Automatic reminders

    • – Reminder scheduler
    • – Editable templates
    • – Preview before send
  5. Week 5

    Dashboard and polish

    • – Who-owes-what view
    • – Client list
    • – Empty states
  6. Week 6

    Launch to first users

    • – Landing page
    • – Onboard 10 designers
    • – Feedback calls
04

How this tool works

Your idea goes to an open model running on Groq, with Google Gemini as a fallback, under strict instructions: be specific to this idea, cut hard, never invent market numbers, and plan for one or two engineers. The answer must match a fixed structure; if it doesn't, the tool asks once more before giving up.

Each feature is also mapped to a building block from the MVP Cost Estimator, so you can price the spec in one click. To keep the free tier free, it's limited to five specs per person per day. Nothing you type is stored on this site.

05

Questions founders actually ask

Is the spec good enough to hand to a developer?
It's a strong first draft: scope, flows, a data model and a plan a developer can react to. Spend 30 minutes editing it with someone who knows your users before treating it as the brief.
Which AI model writes the spec?
Open models through Groq, with Google Gemini as a fallback if Groq is busy. Your idea is sent to the model to generate the spec and isn't stored by this site.
Why is my favourite feature in 'won't have'?
Because an MVP is about learning fast, not about completeness. 'Won't have' means 'not in the first six weeks', usually because a manual workaround exists. Move it if it's truly core to your value.
How do I get a cost for this spec?
Click 'Estimate the cost' after generating. It opens the MVP Cost Estimator with the must and should features already selected.
Is there a usage limit?
Five specs per person per day, plus a daily limit for the whole site, because the AI runs on free tiers. If you hit it, book a call and we'll scope it together.
Should I share a confidential idea here?
Describe what the product does and who it's for; you don't need secret details to get a useful spec. Nothing is stored here, but the text does go to the AI provider to generate the result.
06

More from the workbench

01 · Plan & scopeMVP Cost EstimatorPick features and who builds it. Get an hour-by-hour estimate, not an agency teaser.11 · Plan & scopeTech Stack PickerSix questions about your team and product. One opinionated stack, with the reasoning.06 · Launch & growthAI Landing Page RoastPaste your URL. Get roasted on headline, CTA, proof and clarity, then get the rewrites.

Fine print

Tools: on the house.
Engineer: by the hour.

The plan was free. Shipping it is my day job.

I'm Himanshu, an AI and full-stack engineer. I build MVPs, AI agents and the growth plumbing around them for early-stage startups.

Hire me →My projects