Bilig Workpaper

Bilig WorkPaper Agent Skill

Use this skill when an agent needs spreadsheet-style formulas but the work should run through files, terminal commands, TypeScript, HTTP routes, or MCP tools instead of Excel UI automation.

When To Trigger

Trigger this skill for tasks involving:

• workbook-shaped business logic in Node.js services;
• formula readback after writing cells;
• quote, budget, payout, pricing, import-validation, or forecast models;
• agent spreadsheet tools that need deterministic cell addresses;
• MCP clients that can run a stdio server or call a Streamable HTTP endpoint;
• reduced formula/import bugs that need a local report.

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

Command Safety

Do not build shell commands by concatenating user text. Treat the commands below as literal templates, validate workbook paths before use, and reject values containing newlines, backticks, $(, ;, &, |, <, or >. Prefer MCP client command plus args arrays or direct TypeScript calls when inserting user-provided paths or cell references.

First Check: Agent Triage

Before wiring a client or opening a spreadsheet UI, print the compact decision card:

{
  "command": "npm",
  "args": ["exec", "--yes", "--package", "@bilig/workpaper@latest", "--", "bilig-agent-start", "--json"]
}

First Check: Agent Evaluator

Before wiring a client, prove the published agent door with the package-owned evaluator. It exercises MCP discovery, cell mutation, formula readback, JSON export, restart restore, and returns verified: true:

{
  "command": "npm",
  "args": ["exec", "--yes", "--package", "@bilig/workpaper@latest", "--", "bilig-evaluate", "--door", "agent-mcp", "--json"]
}

For service-owned WorkPaper logic without MCP, run bilig-evaluate --door workpaper-service --json. Use the lower-level challenge commands only when debugging the direct API loop or file-backed MCP JSON-RPC transcript:

[
  { "command": "npm", "args": ["exec", "--package", "@bilig/workpaper@latest", "--", "bilig-agent-challenge", "--json"] },
  { "command": "npm", "args": ["exec", "--package", "@bilig/workpaper@latest", "--", "bilig-mcp-challenge", "--json"] }
]

First Choice: MCP

Use MCP when the host can run a stdio server or call a Streamable HTTP server. Configure stdio as an argument array, not a shell-concatenated string:

If the host supports installable skills, first check that the public skill package is discoverable:

npx --yes skills@latest add https://bilig.proompteng.ai --list
npx --yes skills@latest add proompteng/bilig --skill bilig-workpaper --list

{
  "command": "npm",
  "args": [
    "exec",
    "--package",
    "@bilig/workpaper@latest",
    "--",
    "bilig-workpaper-mcp",
    "--workpaper",
    "__WORKPAPER_PATH__",
    "--init-demo-workpaper",
    "--writable"
  ]
}

Run bilig-evaluate --door agent-mcp --json first. If the workbook contains provider-backed formulas such as IMPORTRANGE, run bilig-evaluate --door agent-mcp --scenario provider-backed --json to confirm the adapter boundary. If the evaluator fails, run bilig-mcp-challenge and treat its returned tools array as the source of truth for the currently published package. The core file-backed tools are:

• list_sheets
• read_range
• read_cell
• set_cell_contents
• set_cell_contents_and_readback
• get_cell_display_value
• export_workpaper_document
• validate_formula

When the server is started through @bilig/workpaper@latest with --from-xlsx ./pricing.xlsx, tools/list also includes analyze_workbook_risk. That tool is fixed to the source XLSX passed at startup and reports workbook risk indicators before a workflow trusts the imported WorkPaper. Without --workpaper --writable, edits stay in memory; add a WorkPaper JSON path only when the task needs persisted file state. It does not certify Excel compatibility.

For a maintained XLSX preflight transcript, run pnpm --dir examples/headless-workpaper run agent:mcp-xlsx-risk-preflight. It requires analyze_workbook_risk, set_cell_contents_and_readback, export_workpaper_document, Inputs!B3, Summary!B3, 60000 -> 96000, and verified: true.

After a write, always read the dependent output cell and export the WorkPaper document. If the listed tool set includes set_cell_contents_and_readback, prefer it for stateless clients because the edit and dependent readback happen in one tool call. If it is absent, call set_cell_contents, then read_cell or read_range, then export_workpaper_document.

For remote MCP clients, use the stateless demo endpoint when the client supports Streamable HTTP:

https://bilig.proompteng.ai/mcp
https://bilig.proompteng.ai/mcp/workpaper

The remote endpoint is request-local and does not write user files. Use it for connector smoke tests, tool discovery, and agent onboarding; use the file-backed stdio command when the workflow must persist a project WorkPaper JSON file.

Second Choice: Direct TypeScript

Use @bilig/workpaper directly when workbook logic belongs in a service, queue worker, test, or route:

import { buildA1WorkPaper } from '@bilig/workpaper'

const book = buildA1WorkPaper({
  Inputs: [
    ['Metric', 'Value'],
    ['Customers', 20],
    ['Average revenue', 1200],
  ],
  Summary: [
    ['Metric', 'Value'],
    ['Revenue', '=Inputs!B2*Inputs!B3'],
  ],
})

const proof = book.editAndReadback('Inputs!B2', 32, {
  readbackRange: 'Summary!B2',
})

console.log({
  editedCell: proof.editedCell,
  after: proof.afterReadback.displayValues,
  afterRestore: proof.restoredReadback.displayValues,
  persistedDocumentBytes: proof.persistedDocumentBytes,
  verified: proof.verified,
})

book.dispose()

Formula Clinic

When the user has a reduced workbook formula/import bug, generate a local report through an argument array:

{
  "command": "npm",
  "args": [
    "exec",
    "--package",
    "@bilig/workpaper@latest",
    "--",
    "bilig-formula-clinic",
    "./reduced.xlsx",
    "--cells",
    "Summary!B7,Inputs!B2"
  ]
}

The report is local. It does not upload workbook contents. Ask for a reduced public fixture rather than private customer spreadsheets.

Required Verification

Return readback, not a write-only claim. A successful agent response should include:

• the exact edited sheet and A1 cell;
• before values for relevant inputs and dependent outputs;
• after values read from the recalculated workbook;
• persistence evidence from serialized or exported WorkPaper state;
• restore or reimport checks when file boundaries matter;
• limitations for unsupported formulas or Excel-only features.

If any readback step fails, report the blocker instead of claiming the workbook was updated.

Reference URLs

• Compact docs map: https://proompteng.github.io/bilig/llms.txt
• Full host context: https://proompteng.github.io/bilig/llms-full.txt
• Host handbook: https://proompteng.github.io/bilig/headless-workpaper-agent-handbook.html
• Agent workbook challenge: https://proompteng.github.io/bilig/agent-workbook-challenge.html
• MCP server guide: https://proompteng.github.io/bilig/mcp-workpaper-tool-server.html
• OpenHands MCP setup: https://proompteng.github.io/bilig/openhands-workpaper-mcp.html
• OpenCode MCP setup: https://proompteng.github.io/bilig/opencode-workpaper-mcp.html
• Open WebUI tool setup: https://proompteng.github.io/bilig/open-webui-workpaper-mcp.html
• LobeHub MCP setup: https://proompteng.github.io/bilig/lobehub-workpaper-mcp.html
• AnythingLLM MCP setup: https://proompteng.github.io/bilig/anythingllm-workpaper-mcp.html
• Sim MCP setup: https://proompteng.github.io/bilig/sim-workpaper-mcp.html
• Formula clinic: https://proompteng.github.io/bilig/formula-bug-clinic.html
• Compatibility limits: https://proompteng.github.io/bilig/where-bilig-is-not-excel-compatible-yet.html
• Repository: https://github.com/proompteng/bilig