Finance · Do this yourself

Turn your AI agent into a bookkeeper for a small business.

✅ Released open source.

No X data

Based on kvisner on Hacker News (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. Export the data you have (bank CSV, invoices, sales report) without account numbers.
  2. Open ChatGPT, Claude or Grok, upload or paste it, and paste the prompt below.
  3. Ask for categories, totals and a short summary of anything unusual.
  4. Spot-check 5 lines by hand; correct the AI where it is wrong.
  5. Ask for a Google Sheets template with formulas so you can repeat it monthly.
  6. Have an accountant check anything that affects taxes.

Ready-to-copy prompt

Import this month’s bank CSV, categorize each transaction, flag anything unusual, and produce a profit and loss summary.

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
$0–20/month (free tiers or one AI plan)Our estimate
Time
1–2 weekendsOur 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

kvisner owns a small tech business with 10-30 transactions a month and built Magpie, a CLI that turns an agent into a bookkeeper.

How it went

Released open source.

Worth knowing

Have an accountant review year-end figures.

Difficulty
IntermediateOur rating
Time to build
Not reportedOur estimate
Monthly cost
Not reported
Revenue
Not reportedWe only show revenue the source states
Engagement
8 HN points0 comments · fetched Oct 15, 2026
X buzz
No X data

Posted · Added Oct 16, 2026

Original builder recipe

  • Magpie CLI
  • Any coding agent
  • Bank CSV exports
  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.

Open the repo ↗ (opens in new tab)

Tags

Tool CLI
Industry Finance

Read the original

More ideas like this

The Daily 5.

Five real AI agent use cases each morning, each with a recipe and a source. Plus a Sunday roundup. Free.