Public API

Workbook

import ExcelJS from './src/vendor/exceljs/exceljs.nodejs.js';

const workbook: ExcelJS.Workbook = new ExcelJS.Workbook();

The central object for all spreadsheet operations. Use it to create, load, and save XLSX files. All worksheets, styles, images, and defined names live on a Workbook instance.

stream.xlsx.WorkbookWriter

import ExcelJS from './src/vendor/exceljs/exceljs.nodejs.js';

const writer = new ExcelJS.stream.xlsx.WorkbookWriter({ filename: 'out.xlsx' });

Streaming XLSX writer that flushes rows to disk/stream as they are written, keeping memory usage flat for large datasets. Use this instead of Workbook when generating files with tens of thousands of rows.

stream.xlsx.WorkbookReader

import ExcelJS from './src/vendor/exceljs/exceljs.nodejs.js';

const reader = new ExcelJS.stream.xlsx.WorkbookReader('./input.xlsx');

Streaming XLSX reader that emits worksheet and row events as the file is parsed. Use when consuming very large XLSX files without buffering the whole document in memory.

ModelContainer

import ExcelJS from './src/vendor/exceljs/exceljs.nodejs.js';

const container = new ExcelJS.ModelContainer();

Wraps a workbook model for serialisation and transport. Used internally when converting between JSON model representation and the full Workbook object.

Working examples

Scenario - Create and write an XLSX file

Build a workbook with a single worksheet, populate rows, and write to disk.

const ExcelJS = require('./src/vendor/exceljs/exceljs.nodejs.js');

async function createSpreadsheet() {
  const workbook = new ExcelJS.Workbook();
  workbook.creator = 'My App';
  workbook.created = new Date();

  const sheet = workbook.addWorksheet('Sales');

  sheet.columns = [
    { header: 'Product', key: 'product', width: 20 },
    { header: 'Revenue', key: 'revenue', width: 15 },
    { header: 'Date',    key: 'date',    width: 15 },
  ];

  sheet.addRow({ product: 'Widget A', revenue: 1200.5, date: new Date('2024-01-15') });
  sheet.addRow({ product: 'Widget B', revenue: 850.0,  date: new Date('2024-01-16') });

  await workbook.xlsx.writeFile('output.xlsx');
  console.log('Written: output.xlsx');
}

createSpreadsheet();

Scenario - Read an existing XLSX file

Load an XLSX file and iterate over every row in the first worksheet.

const ExcelJS = require('./src/vendor/exceljs/exceljs.nodejs.js');

async function readSpreadsheet(filePath: string) {
  const workbook = new ExcelJS.Workbook();
  await workbook.xlsx.readFile(filePath);

  const sheet = workbook.getWorksheet(1);
  sheet.eachRow({ includeEmpty: false }, (row, rowNumber) => {
    console.log(`Row ${rowNumber}:`, row.values);
  });
}

readSpreadsheet('./input.xlsx');

Scenario - Streaming write for large datasets

Use WorkbookWriter to stream tens of thousands of rows without buffering the entire workbook in memory.

const ExcelJS = require('./src/vendor/exceljs/exceljs.nodejs.js');

async function streamWrite() {
  const writer = new ExcelJS.stream.xlsx.WorkbookWriter({
    filename: 'large-output.xlsx',
    useStyles: true,
  });

  const sheet = writer.addWorksheet('Data');
  sheet.columns = [
    { header: 'ID',    key: 'id',    width: 10 },
    { header: 'Value', key: 'value', width: 20 },
  ];

  for (let i = 0; i < 100000; i++) {
    await sheet.addRow({ id: i, value: `item-${i}` }).commit();
  }

  await sheet.commit();
  await writer.commit();
  console.log('Streaming write complete.');
}

streamWrite();

Scenario - Streaming read with event-based row processing

Process a large XLSX file row by row using WorkbookReader without loading the whole file.

const ExcelJS = require('./src/vendor/exceljs/exceljs.nodejs.js');

async function streamRead(filePath: string) {
  const reader = new ExcelJS.stream.xlsx.WorkbookReader(filePath);

  for await (const worksheet of reader) {
    console.log('Worksheet:', worksheet.name);
    for await (const row of worksheet) {
      console.log('Row:', row.values);
    }
  }
}

streamRead('./large-input.xlsx');

File walkthrough

• exceljs.nodejs.js - Assembles the full Node.js API surface: Workbook, ModelContainer, stream.xlsx.WorkbookWriter, stream.xlsx.WorkbookReader, and Enums.
• exceljs.browser.js - Browser entry; loads core-js polyfills before requiring the same Workbook and Enums, omitting Node.js streaming classes.
• exceljs.bare.js - Polyfill-free variant for apps that already bundle their own; exposes only Workbook and Enums.
• csv/ - Contains csv.js (CSV read/write coordinator), line-buffer.js (line-by-line buffering), and stream-converter.js (stream adaptor for fast-csv).
• doc/ - Domain model layer. workbook.js is the Workbook class; worksheet.js, row.js, cell.js, column.js represent spreadsheet structure. enums.js exports alignment, border, and font constants. table.js, pivot-table.js, image.js, note.js handle rich features.
• stream/xlsx/ - Streaming counterparts: workbook-writer.js and workbook-reader.js for memory-efficient large file handling; worksheet-reader.js and worksheet-writer.js for per-sheet streaming; helper writers for comments and relationships.
• utils/ - Low-level helpers: col-cache.js (A1/RC conversion), shared-strings.js (string table), xml-stream.js (XML generation), zip-stream.js (ZIP assembly), encryptor.js (XLSX encryption), utils.js (general helpers), string-buf.js and stream-buf.js (buffering).
• xlsx/ - XLSX format engine. xlsx.js orchestrates read/write. xform/ contains transform objects for every XML part (sheet, style, drawing, table, pivot-table, strings). defaultnumformats.js maps built-in number format IDs.

Common pitfalls and fixes

• tmp module writes to system temp: On restricted environments (Docker scratch, read-only FS) streaming reads may fail; set TMPDIR to a writable path before starting the process.
• ESM/CJS interop: All source files use CommonJS require. If your project uses "type": "module" in package.json, import via createRequire or rename the entry to .cjs.
• Missing polyfills in browser builds: exceljs.browser.js requires core-js and regenerator-runtime; install them explicitly or switch to exceljs.bare.js and add your own polyfill pipeline.
• archiver vs jszip for write path: The non-streaming Workbook.xlsx.writeFile uses jszip; the streaming WorkbookWriter uses archiver. Both must be installed even if you only use one path.
• Large file memory use with Workbook: Loading a 50 MB XLSX with workbook.xlsx.readFile buffers the entire file. Switch to stream.xlsx.WorkbookReader for files above a few MB.
• Worksheet name restrictions: Names may not contain \ / ? * [ ] : and must be 31 characters or fewer; the library will throw at write time, not at addWorksheet time.

Vibe-coding prompt template

I have the ExcelJS 4.4.0 library source code in `source/` and its integration
guide in `USAGE.md`. The upstream package is `user@example.com`.

Please help me integrate this into my existing Node.js/TypeScript project:

1. Read `USAGE.md` fully before writing any code.
2. Copy `source/` to `src/vendor/exceljs/` and wire the path alias in
   `tsconfig.json` as shown in USAGE.md § Project setup.
3. Install all dependencies listed in USAGE.md § Required dependencies.
4. In my Express route `src/routes/export.ts`, add a POST handler that:
   - Accepts a JSON body `{ rows: Array<{ id: number; label: string }> }`
   - Uses `ExcelJS.Workbook` (from `exceljs.nodejs.js`) to build an XLSX
   - Streams the file back to the client with content-type
     `application/vnd.openxmlformats-officedocument.spreadsheetml.sheet`
5. Add a second route that uses `stream.xlsx.WorkbookWriter` for large exports.
6. Show only real imports from the file excerpts in USAGE.md; do not invent
   any API not shown there.
7. Walk me through each step before writing code, then produce the final files.

License and credit

ExcelJS is published under the MIT License. See source/LICENSE if present, or refer to the upstream repository. Upstream package: exceljs on npm / github.com/exceljs/exceljs.

This product’s unique contribution is clean room implementation of valuable code block into AVCP compatible standard.

The full install guide and integration prompts unlock after purchase.

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