XLSX Quickstart

This is the fastest path to first value with CmdCal XLSX:

install @paperjsx/json-to-xlsx
describe your workbook as structured JSON
render a real .xlsx
open it in Excel, Numbers, Sheets, or LibreOffice

Install

Terminal

pnpm add @paperjsx/json-to-xlsx

First Render

TYPESCRIPT

import fs from "node:fs/promises";
import { SpreadsheetEngine } from "@paperjsx/json-to-xlsx";

const workbook = {
  meta: {
    title: "Quarterly Revenue",
    creator: "CmdCal",
  },
  sheets: [
    {
      name: "Revenue",
      rows: [
        {
          cells: [
            { value: "Quarter" },
            { value: "Revenue" },
            { value: "Closed" },
            { value: "As Of" },
          ],
        },
        {
          cells: [
            { value: "Q1 2026" },
            { value: 420000 },
            { value: true },
            { value: new Date("2026-03-31T00:00:00.000Z") },
          ],
        },
        {
          cells: [
            { value: "Q2 2026" },
            { value: 510000 },
            { value: false },
            { value: new Date("2026-06-30T00:00:00.000Z") },
          ],
        },
      ],
    },
  ],
};

const buffer = await SpreadsheetEngine.render(workbook);
await fs.writeFile("revenue-report.xlsx", buffer);

That gives you:

a real OOXML workbook, not CSV-with-styles
native worksheet structure
typed values for strings, numbers, booleans, and dates
deterministic output by default

Download The Same Example

JSON workbook spec: quickstart-revenue.json
Rendered workbook: quickstart-revenue.xlsx

Validate Before Rendering

If you want schema validation before hitting the render path:

TYPESCRIPT

import { SpreadsheetEngine } from "@paperjsx/json-to-xlsx";

const validated = SpreadsheetEngine.validateDocument(workbook);
const buffer = await SpreadsheetEngine.renderValidated(validated);

Add Styles, Filters, and Tables

Once the first render works, the next common step is adding the features users expect from a real export.

TYPESCRIPT

const workbook = {
  sheets: [
    {
      name: "Revenue",
      autoFilter: true,
      rows: [
        {
          cells: [
            { value: "Quarter", style: { font: { bold: true } } },
            { value: "Revenue", style: { font: { bold: true } } },
            { value: "Margin", style: { font: { bold: true } } },
          ],
        },
        {
          cells: [
            { value: "Q1" },
            { value: 420000, style: { numberFormat: "$#,##0" } },
            { value: 0.24, style: "percentage" },
          ],
        },
      ],
      tables: [
        { name: "RevenueTable", ref: "A1:C2" },
      ],
    },
  ],
};

What To Learn Next

Need operational trust: see Validation & Repair
Working from customer templates: see Templates & Large Workbooks
Building agent workflows: see MCP & Agents
Want more runnable files: see Examples & Downloads

Good Fit

CmdCal XLSX is a strong fit when:

your export logic is currently brittle and imperative
you need formatting, tables, validations, templates, or print setup
you want agent-friendly structured JSON in and real Excel out
you need generation plus validation and repair, not just file creation

Current Limits

true streaming write is still an active roadmap item
cross-app desktop validation still depends on external target apps
some broader repair rules remain intentionally conservative

That is deliberate: the engine prefers explicit validation errors and conservative repair logs over silent mutation.