xlsx-formula-recalc - SKILL.md Agent Skill

name: xlsx-formula-recalc version: 0.1.0 description: Recalculate XLSX formula outputs in Node.js after cell edits without opening Excel, LibreOffice, or browser automation. tags: - xlsx - excel - formula-recalculation - node - spreadsheet-automation - typescript

XLSX Formula Recalculation

Use @bilig/xlsx-formula-recalc when an agent or Node.js service has changed XLSX inputs and must read recalculated formula outputs without opening Excel, LibreOffice, or a browser. The unscoped xlsx-formula-recalc package remains a compatibility/search alias; new agent instructions should use the scoped package first.

First Check

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- bilig-evaluate --door workbook-compatibility --json
npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- bilig-evaluate --door xlsx-cache --json

Use workbook-compatibility when you need a local preflight report for a real workbook before a Node service or agent trusts it. The report lists unsupported functions, external links, macro payloads, pivots, volatile functions, stale caches, and concrete risk reasons. It does not certify Excel compatibility and must not grow a compatibility score.

The cache evaluator should print schemaVersion: "bilig-evaluator.v1", door: "xlsx-cache", verified: true, and evidence for a stale cached formula corrected to a Summary!B2 value of 72000.

For SheetJS / xlsx stale-formula issues, use the SheetJS-named binary from the same package:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- sheetjs-recalc --demo --json

If you have a real workbook but do not yet know which formula cells to verify, inspect it without writing an output file:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- xlsx-recalc workbook.xlsx --inspect --json

For CI or issue triage, use the cache-diagnosis alias:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- xlsx-cache-doctor workbook.xlsx --json

For workbook risk review, use the compatibility report:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- workbook-compatibility-report workbook.xlsx --json

The inspection output includes formulaCellCount, staleCachedFormulaCount, suggestedReads, and a nextStep.command for the recalculation proof. Default inspection checks every formula. If a workflow sets --inspect-limit, require uninspectedFormulaCellCount: 0 before treating the report as complete coverage.

Real Workbook

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- xlsx-recalc workbook.xlsx \
  --set Inputs!B2=48 \
  --read Summary!B7 \
  --out workbook.recalculated.xlsx \
  --json

For linked workbooks, pass companion files:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- xlsx-recalc workbook.xlsx \
  --external-workbook rates.xlsx \
  --read Summary!B7 \
  --json

Use an exact target binding when the workbook link target differs from the local filename:

npm exec --yes --package @bilig/xlsx-formula-recalc@latest -- xlsx-recalc workbook.xlsx \
  --external-workbook-target ./fixtures/rates-current.xlsx file:///tmp/rates.xlsx \
  --read Summary!B7 \
  --json

TypeScript

import { recalculateXlsxFileToFile } from '@bilig/xlsx-formula-recalc'

const result = await recalculateXlsxFileToFile('workbook.xlsx', {
  outputPath: 'workbook.recalculated.xlsx',
  edits: [{ target: 'Inputs!B2', value: 48 }],
  reads: ['Summary!B7'],
  engine: 'streaming-native',
})

For the older bytes-in/bytes-out WorkPaper path, import from @bilig/workpaper/xlsx and install @bilig/workpaper explicitly.

Prefer exceljs-formula-recalc when the caller already owns an ExcelJS Workbook object and wants read results patched back into that object.