TrueCalc
← Finance & audit

Review a change to a model the way you review code

A workbook serialises to RFC 8785 canonical JSON. Two people who build the same model get byte-identical files, so a diff shows what actually changed instead of what the spreadsheet happened to reorder.

workbook.truecalc.appOpen in full
Q4 ARR
2,037,254

B10

Growth over the year
69.8

B13

Verified at build timeThese figures are produced by running the grid above through the engine during the build. If the engine ever disagrees with them, this page does not ship.

Change net retention from 1.08 to 1.12 and the diff is one line — the assumption — plus the cells that actually moved. That is a review a person can do.

The same thing, in code

Nothing here is playground-only.

The grid above and the snippet below run the same engine. Whatever you can do in the sheet, you can do from your own program.

// Change one assumption; commit the result.
wb.set('Model', 'B3', '1.12');
wb.recalc(JSON.stringify({ timestamp_ms: 0, timezone: 'UTC', rng_seed: 0 }));

// Canonical JSON: same model, same bytes, on any machine.
const snapshot = wb.toJSON();

Take it further

Shipped for the engine and the workbook format. The explainability layer above it — showing how a number was derived — is not released.

Also in finance & audit