formulon-mcp
A local stdio MCP server for Formulon. Agents can inspect and edit Excel workbooks, recalculate formulas, author printable documents, preview ranges, audit copied formulas, and create native Tables and PivotTables.
Full documentation lives on the Formulon website. It covers tool inputs, responses, limits, and end-to-end examples.
Quick start
Requires Node.js 22 or newer; see engines. Register the server with the bundled interactive installer:
npx -y @libraz/formulon-mcp init
Choose Claude Code, Codex CLI, or Claude Desktop, then the Excel locale and host (Windows or Mac) that new sessions evaluate with. The locale sets number and date text, TEXT formats, text comparison, and double-byte text functions; it defaults to the system locale. Review the configuration changes and restart the client. Ask the agent to evaluate =SUM(10,20,30) using Formulon; the result is 60.
For scripted setup, pass the profile directly, for example init --profile win-365-ja_JP. A single session can still pick another profile when it is opened.
See installation for manual client configuration, local checkouts, and troubleshooting. Remove registration with npx -y @libraz/formulon-mcp uninstall.
Guides
| Task | Documentation |
|---|---|
| Edit a workbook template and save a copy | Workbook workflow |
| Create an invoice with formulas and print settings | Document authoring |
| Reproduce a form and inspect its appearance | Layout and previews |
| Find overwritten or missing formulas | Formula audit |
| Summarize sales data | Tables and pivots |
| Inspect tool inputs or discover a low-level method | Tools · Advanced API |
Sessions live in memory and disappear when the server stops. Use explicit output paths and review load/save diagnostics. Preview rendering is approximate; formula audits report review candidates. See the security model.
Development
yarn install
yarn run check
yarn test
Tests build and exercise dist/. The calculation engine is maintained in the separate Formulon repository.
License
Apache-2.0. See LICENSE.