Bilig WorkPaper

Overview

Bilig WorkPaper gives agents a reviewable spreadsheet model without requiring browser or Excel UI automation. Use it to edit cells through an API, recalculate formulas, verify display-value readback, and persist WorkPaper JSON for audit or restore flows.

When to Use This Skill

• Use when an agent needs spreadsheet-style formulas in a backend service or local workflow.
• Use when the task involves editing input cells, recalculating formulas, and proving the output with readback.
• Use when Excel, Google Sheets, or screenshot-driven spreadsheet automation would be too brittle.
• Use when a workflow needs file-backed WorkPaper JSON that can be reviewed, restored, or versioned.

Step-by-Step Guide

1. Install or run the package

Use the package directly with npm exec when you only need the MCP server:

npm exec --package @bilig/headless -- bilig-workpaper-mcp --workpaper ./pricing.workpaper.json --init-demo-workpaper --writable

For TypeScript code, install the package in the project:

npm install @bilig/headless

2. Prefer WorkPaper state over UI automation

Keep workbook state in a WorkPaper JSON document. Write inputs through the WorkPaper API or MCP tools, recalculate, then read the computed display value back from the model.

3. Use the MCP tools for agent workflows

A file-backed MCP session should expose tools for listing sheets, reading cells or ranges, setting cell contents, validating formulas, exporting the document, and reading display values after recalculation.

4. Verify after every mutation

After each write, read the changed input cell and the dependent output cell. Keep the exported WorkPaper JSON when the task needs proof, rollback, or a reproducible bug report.

Examples

Example 1: File-backed MCP server

npm exec --package @bilig/headless -- bilig-workpaper-mcp --workpaper ./pricing.workpaper.json --init-demo-workpaper --writable

An agent can then update Inputs!B3, read Summary!B3, and export the updated WorkPaper JSON.

Example 2: TypeScript service workflow

import { WorkPaper } from "@bilig/headless";

const paper = new WorkPaper();
paper.setCellContents("Inputs", "B2", 1200);
paper.setCellContents("Inputs", "B3", "=B2*1.2");
paper.recalculate();

const result = paper.getCellDisplayValue("Inputs", "B3");
console.log(result);

Best Practices

• Do use Bilig for formulas, readback, and persisted spreadsheet state when the workflow can live outside Excel UI.
• Do keep formula inputs, computed outputs, and exported WorkPaper JSON together when reporting bugs or validating agent changes.
• Do validate formulas before writing them into cells when the agent is generating formulas.
• Don't use screenshot or browser automation for spreadsheet logic if a WorkPaper API call can express the same operation directly.
• Don't treat a write as complete until a readback proves the computed output changed as expected.

Troubleshooting

Problem: The agent wrote a formula but the output did not change. Solution: Recalculate the WorkPaper, then read both the input cell and the dependent display-value cell.

Problem: The workflow needs to preserve state across agent turns. Solution: Run the MCP server with --workpaper ./file.workpaper.json --writable and export the document after important changes.