TrueCalc

Where things stand

What is real, and what is not.

Every other page on this site describes software you can install right now. This page is where everything that is not yet built lives, so the rest of the site never has to hedge.

Shipped

MIT licensed. Installable today.

  • The engine, in Rust, with exact Google Sheets semantics
  • JavaScript and TypeScript via WebAssembly, on npm and JSR
  • A workbook layer with a dependency graph and recalculation
  • Canonical JSON workbooks that round-trip across every surface
  • The MCP server, with twelve tools and stateful workbooks
  • The browser playground at try.truecalc.app
  • A Google Sheets conformance corpus, published and auditable

Not yet

No dates. Nothing here is available to buy or sign up for.

Python bindings

The bindings build from source in the repository today. What is missing is a published package — until that exists, there is no install command worth printing.

A hosted API

For teams who want server-side evaluation without embedding WebAssembly or running Rust. Not built. There is nothing to sign up for.

Hosted MCP with persistent workbooks

Today the MCP server holds workbooks in memory for the life of the process. Surviving across sessions means somewhere to keep them, which means accounts — none of which exist yet.

Explainability and evidence

Showing how a number was derived, and being able to recompute it years later and prove it identical. The engine already exposes the hook this needs. The layer above it is unreleased.

Excel semantics

The Excel flavour parses and validates but does not evaluate — it returns #UNSUPPORTED!. Sheets is the engine that works today, and the site says so everywhere.

What would you build on?

The order these get built in is not fixed. If one of them is the thing standing between you and shipping, that is genuinely useful to know.