Finance · Do this yourself

Vibe code an invoicing SaaS for freelancers to 100 paying users.

💰 A Reddit user makes about $2k a month doing this. ~$2k MRR (self-reported)

No X data

Based on A Reddit user on Reddit (opens in new tab)

Who it’s for

Business owners, freelancers, bookkeepers and anyone tracking money.

Adapt it to your industry

  • Restaurant: weekly food-cost summary from invoices
  • Freelancer: sort expenses for tax time
  • Agency: monthly profit per client in one sheet

Step by step

  1. Write down one problem a specific group of people pays to solve (for example “gym owners losing members”).
  2. Open ChatGPT, Claude or Grok and paste the prompt below to sharpen the idea and list what the first version must do.
  3. Use ChatGPT, Claude or Grok plus Google Sheets or Excel to make the first version of the product for one type of customer.
  4. Create a Stripe account and a Payment Link so people can pay from day one.
  5. Make a one-page website that explains the problem, the fix and the price.
  6. Show it to 10 people from your target group and change what confuses them.
  7. Launch where those people already gather, then ask every new user for feedback.

Ready-to-copy prompt

Build a minimal invoicing app: create a client, generate a PDF invoice, email it, and send automatic reminders until it is marked paid.

Start with AI

Opens the AI with this guide and the prompt filled in.

Open in ChatGPT (opens in new tab)Open in Claude (opens in new tab)Open in Grok (opens in new tab)
Cost
$0–100/month to start (AI plan, builder, domain)Our estimate
Time
2–6 weeks for a first versionOur estimate

How to make money from it

Pricing idea: Offer monthly bookkeeping or reporting for a fixed fee per client.

Finding your first 10 customers

  • Do one month for free for a business you know.
  • Ask for a testimonial with the time saved.
  • Partner with an accountant who needs help with small clients.

Ideas, not promises. Results vary.

Details: source, numbers and tags

What they did

He used Cursor for the React frontend and Node backend and Claude for complex logic like PDFs and cron jobs, launched an ugly v1 on Product Hunt, and added features users asked for.

How it went

He reports 100 paying users and about $2k MRR; 20 signups in launch week, about half converted after a trial.

Worth knowing

His advice: do not let AI overcomplicate things; it is a tool, not a brain.

Difficulty
IntermediateOur rating
Time to build
Not reportedOur estimate
Monthly cost
Not reported
Revenue
~$2k MRR (self-reported)Self-reported: The founder’s own claim; not verified by us
Engagement
No public countThe source shows no number
X buzz
No X data

Posted · Added Oct 16, 2026

Original builder recipe

  • Cursor
  • Claude
  • React
  • Node/Express
  1. Connect or export your financial data.
  2. Have the agent categorize and summarize it.
  3. Check the numbers against your statements.
  4. Schedule recurring reports.

Tags

Industry Finance Software

Read the original

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