Ask your spreadsheets. Get a workbook back. No number made up.

If you run a small business, you have probably tried asking an AI chatbot about your sales spreadsheet. It answers instantly, sounds sure of itself, and now and then gets a total wrong in a way you only notice when a customer does. Along the way, you uploaded your customer list to someone else's server.

Kowalski 2.1 is our answer to both problems. It is a free, open-source app that runs on your own Mac or Linux machine and hands everyday chores to a horde, a small team of AI agents that each do one job. Three hordes cover the chores we hear about most.

1. "Who were our best customers last quarter?"

You load your workbook into tableski, which turns every sheet into a table, open Kowalski, pick the Spreadsheet analyst and type your questions, one per line:

Who spent the most in total across the orders?

How many people are active?

How many people live in each city?

A few minutes later you have two files. report.xlsx has an index sheet and one sheet per question, with real numbers you can sort and chart. HANDOFF.md has the short answers:

Who spent the most? Ada spent the most, with a total of 150.5, followed by Linus with 99.99.

How many people are active? There are 2 active people.

People per city: not answerable from these tables. The data has no city column.

That last answer matters as much as the first two. The AI did not invent a city breakdown to be helpful. It said the data cannot answer the question, and why.

Why the numbers can be trusted

Six agents take part, and four of them use no AI at all. One reads your tables' columns and types, another runs the queries, another builds the workbook. The AI does two things: it turns each question into a SQL query, and afterwards it explains the results it is handed. It never adds up a column itself. Every figure in the workbook came out of a database engine, and the exact query behind each answer is saved next to it, in case your accountant asks.

2. A morning brief from the pages you already check

Most of us open the same five tabs every morning: a news site, a competitor's price list, a supplier's announcements, an industry newsletter. The Morning brief horde reads them for you and writes one page: a top pick, then the few items from each page that match what you told it you care about, each with its link.

It can run by itself at 7:00 on weekdays. That schedule ships switched off. Nothing runs, or costs anything, until you turn it on.

3. The paperwork in your inbox

Point the Folder watcher at an inbox folder and drop documents into it: invoices, order confirmations, a contract. For each one you get a short note. Here is the note for a supplier invoice from our testing:

Invoice from ACME Packaging Ltd, September 2026

Key facts: 2,000 boxes at €0.62; VAT €285.20; total due €1,525.20.

What to do: pay €1,525.20 by 17 October 2026.

Watch out: a 5% surcharge after 17 October, and the unit price rises to €0.71 on 1 November.

The price rise was one line at the bottom of the invoice. That is the line you would have missed.

Your machine, your files, your choice of AI

• It runs on your computer. Your spreadsheets and documents stay on your disk. Kowalski only talks to the AI model you choose and the pages you ask it to read.
• Free, or bring your own key. With Ollama the AI runs on your machine at no cost (a recent laptop is enough; a bigger one is faster). Or connect any OpenAI-compatible service with your own key and pay only for what you use.
• It asks before it acts. Any step that would run a command or change files stops and shows you what it is about to do. It continues only when you press Approve.
• You can read everything it does. Each horde is a folder of plain text files, and every run leaves its working files behind: the questions, the queries and the raw results.

Two lines to try it

On a Mac or Linux machine, open the Terminal and paste:

curl -fsSL https://raw.githubusercontent.com/yarenty/kowalski/main/install.sh | bash
kowalski

Your browser opens on a setup screen with three questions: which AI to use, which folder the agents may work in, and (optional) your tableski account. Then pick a horde and give it something to do.

Kowalski is open source under the MIT licence, at github.com/yarenty/kowalski. If a chore of yours would make a good fourth horde, tell us. That is how these three were chosen.