bilig

Sim WorkPaper MCP setup

Use this when a Sim workflow needs spreadsheet-shaped business logic, but the formula state should live behind explicit WorkPaper tools instead of Excel UI automation, browser grid clicks, or stale XLSX cached values.

Sim’s MCP tool setup adds external MCP servers from Settings -> MCP Tools. Sim documents Streamable HTTP server URLs, connection testing, Agent-block tool use, and a standalone MCP Tool block for deterministic calls.

Official Sim references:

Fastest smoke test: hosted Streamable HTTP

Use this when you only need to prove that Sim can discover and call the Bilig WorkPaper tools.

In Sim:

Open Settings -> MCP Tools.
Click Add.
Set Server Name to bilig-workpaper.
Set Server URL to https://bilig.proompteng.ai/mcp.
Leave headers empty.
Keep transport as Streamable HTTP.
Click Test Connection and confirm the WorkPaper tools are discovered.
Save the server.

The hosted endpoint is stateless and request-local. It proves tool discovery and formula readback, but it does not persist a private project file.

Agent block proof

Use this when the workflow should let the model choose the WorkPaper tool calls.

Open an Agent block.
Add tools from the bilig-workpaper MCP server.
Select the WorkPaper tools.
Use a prompt that requires readback and persistence proof:

Use the Bilig WorkPaper MCP tools. List the tools, read the sample sheets, set
Inputs!B3 to 0.4, read Summary!B3, export the WorkPaper document, and return
editedCell, before, after, afterRestore, persistedDocumentBytes, verified, and
limitations. Do not claim success from a write call alone.

The useful Bilig 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

Expected proof fields include:

{
  "editedCell": "Inputs!B3",
  "dependentCell": "Summary!B3",
  "before": 60000,
  "after": 96000,
  "verified": true
}

verified should only be true after the dependent formula output is read back.

Standalone MCP Tool block

Use Sim’s standalone MCP Tool block when the workflow step should be deterministic instead of model-selected.

One practical shape:

read_cell or read_range to capture the current input and dependent output.
set_cell_contents with Inputs!B3 = 0.4.
get_cell_display_value for Summary!B3.
export_workpaper_document so downstream blocks can store or inspect the WorkPaper proof object.

That keeps the calculation repeatable: Sim owns the workflow routing, and Bilig owns the formula workbook state and readback contract.

Private workbook state

The hosted endpoint is only a smoke test. For a private or writable project WorkPaper, expose your own Bilig WorkPaper MCP endpoint on a domain that your Sim workspace can reach, then add that URL in Settings -> MCP Tools.

For self-hosted Sim deployments with domain allowlisting, include the private Bilig MCP host in ALLOWED_MCP_DOMAINS.

Before putting a private endpoint behind Sim, prove the file-backed local MCP contract from a terminal:

npx -y --package @bilig/workpaper@latest bilig-mcp-challenge --json

Expected local proof:

{
  "transport": "stdio-json-rpc",
  "editedCell": "Inputs!B3",
  "dependentCell": "Summary!B3",
  "before": 60000,
  "after": 96000,
  "afterRestore": 96000,
  "afterRestart": 96000,
  "persistedDocumentBytes": 1162,
  "verified": true
}

Boundaries

Sim connects to MCP server URLs over Streamable HTTP. Do not paste a local stdio command into Sim’s Server URL field.
Hosted Streamable HTTP is stateless. Use a private reachable Bilig MCP endpoint when a workflow needs durable workbook state.
Agent blocks let the model choose tools. Use the standalone MCP Tool block for structured, repeatable workflow steps.
Keep Excel or another workbook oracle in the loop for macros, pivots, charts, external links, and layout fidelity.

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