Bilig WorkPaper

Overview

Bilig WorkPaper gives agents a code-first workbook runtime for spreadsheet-style business logic. Use it when the task is easier to model as sheets and formulas, but the reliable path is to edit cells through an API, recalculate, read computed values back, and persist a JSON workbook document.

The main use case is replacing fragile spreadsheet UI automation with deterministic tool calls. It is useful for quote calculators, payout models, budget checks, import validation, and reduced XLSX formula bug reports.

When To Use This Skill

Use this skill when the user needs to:

• work with spreadsheet formulas from a Node.js service, route, test, or agent tool;
• write workbook inputs and verify calculated outputs with readback proof;
• persist a formula workbook as reviewable WorkPaper JSON;
• expose a file-backed workbook through MCP tools;
• investigate an XLSX formula recalculation issue without automating Excel, LibreOffice, or a browser grid.

Do not use it for manual spreadsheet editing, VBA/macros, pivots, charts, COM automation, or exact desktop Excel behavior unless the user explicitly asks to compare against Excel as an oracle.

Safer Command Pattern

Prefer argument arrays in MCP/client configuration. Do not shell-concatenate user-provided paths, sheet names, formulas, or cell addresses. Reject path or cell input containing newlines, backticks, $(, ;, &, |, <, or > before using it in a command.

The MCP examples execute the public @bilig/workpaper npm package. Treat that as third-party code execution: pin the package version you reviewed, run it only in a trusted project, and get explicit user approval before starting a writable MCP server.

Quick MCP Setup

First prove the package-owned challenge works:

{
  "command": "npm",
  "args": ["exec", "--package", "@bilig/workpaper@<reviewed-version>", "--", "bilig-mcp-challenge"]
}

Then run a writable file-backed MCP server:

{
  "command": "npm",
  "args": [
    "exec",
    "--package",
    "@bilig/workpaper@<reviewed-version>",
    "--",
    "bilig-workpaper-mcp",
    "--workpaper",
    "./pricing.workpaper.json",
    "--init-demo-workpaper",
    "--writable"
  ]
}