Made for Swiss self-employed & SMEs
In October 2026, the tool reviewers at SkipCI highlighted an open-source project called GridCraft: a complete spreadsheet program, rebuilt from scratch, that opens and saves the very same .xlsx workbooks Microsoft Excel does. There is no Excel code inside — and still your files just work. The part that matters for a small office goes one step further: every button in the program doubles as a command that an AI assistant can carry out. Here is what that means in practice — and where the honest limits sit.
What GridCraft is, in plain language
GridCraft is what engineers call a “clean-room rebuild”: a team studied how Excel files behave, then wrote brand-new software from zero, without touching a single line of Microsoft code. The result reads and writes real .xlsx files. Formulas, tables, pivot tables, charts and conditional formatting survive a save-and-reopen round trip, and CSV files open too.
The screen feels familiar: a ribbon at the top, a formula bar, the usual keyboard shortcuts, Paste Special. The project lists more than 500 worksheet functions, including modern ones like LET and LAMBDA. It is free, open source, runs on macOS, Windows and Linux — and it sends no telemetry: your numbers stay on your own computer.
A spreadsheet an AI can operate directly
The feature the reviewers flagged first is the “agent-native” design. Every ribbon button, menu entry and keystroke in GridCraft also exists as a command that an AI assistant can call — through a standard interface (an “MCP server”, the emerging plug that connects AI assistants to everyday programs) or through the command line.
In everyday terms: instead of an AI guessing what it sees on a screenshot, it gets real hands. You could ask it to “tidy the client column, build a pivot table per canton, and add a chart” — and the program performs those clicks itself. You keep the last word: nothing leaves the machine until you have checked the result and saved it.
One note on costs: the spreadsheet itself needs no API key and no subscription. Only when you connect your own AI assistant does that assistant’s usage cost money — the same as with any AI you already use.
The honest catches
- Ready-made installers are not published yet. Today the program is built from its source code with developer tools (Rust and cargo). That is fine if a tech-minded person sits within reach — everyone else should wait for a packaged version.
- Old .xls files (the Excel 97–2003 format) bring over their values, formulas and number formats, but not yet their layout or embedded objects. The newer .xlsx format is the native one; XLSB and ODS files arrive as plain values.
- The function count and the speed claims come from the project’s own documentation. No independent test has confirmed them yet.
- An assistant that can press every button can also press the wrong one. For VAT statements, salaries and invoices, the final check stays yours.
What a small office should take from it
For most Swiss self-employed people and small firms the sensible reading is: this is a direction, not a must-install. Two shifts are worth noticing. Office software is becoming local and private again — files that never leave your own machine sit comfortably with the revised Swiss data protection law. And programs are learning to be driven by AI directly, not only by mouse.
- If you can build it, or hire an hour of help: start with a copy of a workbook, never with the original.
- Open the copy in GridCraft, save it, reopen it in Excel — and compare formulas, formatting and charts.
- Give the assistant small, checkable jobs first: sort a column, clean duplicates, build a pivot table. Confirm every result.
- Keep Excel or your fiduciary software for everything that goes to the tax office.
Treat GridCraft as a preview of the next office normal: one program that speaks both human — a familiar ribbon — and machine, through a complete command set, on your own computer, for free. The tools your office runs on are learning to be operated. Make sure the operating instructions stay in your hands.
