The Complete Production SOP: How to Deploy and Run SheetJS In-Browser Spreadsheet Engine in Autonomous AI Agents

---
name: "sheetjs-client-excel-processor"
description: "Parse, manipulate, and export Excel and CSV spreadsheets client-side with SheetJS."
metadata:
  author: "SheetJS"
  version: "1.0.0"
  runtime_compatibility:
    - "codex"
    - "claude-code"
    - "cursor"
    - "windsurf"
triggers:
  - "parse excel file in browser"
  - "export json to excel sheetjs"
  - "convert csv to xlsx javascript"
permissions:
  fs_read: true
  fs_write: "workspace"
  shell_exec: false
  net_access: false
---

{
  "compilerOptions": {
    "target": "ES2022",
    "module": "ESNext",
    "moduleResolution": "Bundler",
    "lib": ["DOM", "DOM.Iterable", "ESNext"],
    "strict": true,
    "skipLibCheck": true
  }
}

import * as XLSX from 'xlsx';

export async function parseExcelFile<T = Record<string, unknown>>(file: File): Promise<T[]> {
  const buffer = await file.arrayBuffer();
  const workbook = XLSX.read(buffer, { type: 'array' });
  const firstSheetName = workbook.SheetNames[0];
  if (!firstSheetName) throw new Error('Uploaded workbook contains no visible sheets.');
  const worksheet = workbook.Sheets[firstSheetName];
  return XLSX.utils.sheet_to_json<T>(worksheet, { defval: null });
}

export function exportJsonToExcel(data: Record<string, unknown>[], filename: string = 'export.xlsx'): void {
  const worksheet = XLSX.utils.json_to_sheet(data);
  const workbook = XLSX.utils.book_new();
  XLSX.utils.book_append_sheet(workbook, worksheet, 'Data');
  XLSX.writeFile(workbook, filename.endsWith('.xlsx') ? filename : `${filename}.xlsx`);
}

import { describe, it, expect } from 'vitest';
import * as XLSX from 'xlsx';
import { parseExcelFile, exportJsonToExcel } from './excelProcessor';

describe('excelProcessor', () => {
  it('correctly converts sheet data to json objects', async () => {
    const sampleData = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }];
    const ws = XLSX.utils.json_to_sheet(sampleData);
    const wb = XLSX.utils.book_new();
    XLSX.utils.book_append_sheet(wb, ws, 'Sheet1');
    const rawArray = XLSX.write(wb, { type: 'array', bookType: 'xlsx' });
    const file = new File([rawArray], 'test.xlsx', { type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' });

    const parsed = await parseExcelFile(file);
    expect(parsed).toEqual(sampleData);
  });
});