Semantic Kernel WorkPaper MCP Plugin

Microsoft Semantic Kernel can import tools from MCP servers. That makes it a good host for Bilig when a Python agent needs formula-backed spreadsheet logic but should not drive Excel, LibreOffice, Google Sheets, or a browser grid.

Semantic Kernel owns the MCP plugin host. Bilig owns the WorkPaper file, formula recalculation, JSON persistence, and read-after-write proof.

Official Semantic Kernel references:

• https://learn.microsoft.com/en-us/semantic-kernel/concepts/plugins/adding-mcp-plugins
• https://devblogs.microsoft.com/agent-framework/semantic-kernel-adds-model-context-protocol-mcp-support-for-python/

Run The No-Key Smoke

git clone https://github.com/proompteng/bilig.git
cd bilig
uv run --python 3.12 --with 'semantic-kernel[mcp]' \
  python examples/semantic-kernel-workpaper-mcp/semantic_kernel_workpaper_mcp.py \
  --workpaper .tmp/pricing.workpaper.json \
  --output .tmp/semantic-kernel-workpaper-proof.json

The command starts the published @bilig/workpaper@latest MCP server. It does not require an OpenAI, Microsoft, Excel, LibreOffice, or Google Sheets key.

Expected top-level output:

{
  "framework": "semantic-kernel-mcp",
  "pluginName": "BiligWorkPaper",
  "packageSpec": "@bilig/workpaper@latest",
  "dependentCell": "Summary!B3",
  "beforeExpectedArr": 60000,
  "afterExpectedArr": 96000,
  "afterRestartExpectedArr": 96000,
  "verified": true
}

The full proof includes the imported tool names, edited cell, before/after input content, dependent formula readback, persisted WorkPaper path, and a restart readback from the same JSON file.

Use --local-source only when you are changing the local TypeScript MCP server and need to verify unreleased behavior from the repository checkout.

Plugin Shape

from semantic_kernel import Kernel
from semantic_kernel.connectors.mcp import MCPStdioPlugin

async with MCPStdioPlugin(
    name="BiligWorkPaper",
    description="Bilig WorkPaper spreadsheet formula tools",
    command="npm",
    args=[
        "exec",
        "--yes",
        "--package",
        "@bilig/workpaper@latest",
        "--",
        "bilig-workpaper-mcp",
        "--workpaper",
        "./pricing.workpaper.json",
        "--init-demo-workpaper",
        "--writable",
    ],
    load_prompts=False,
    request_timeout=30,
) as plugin:
    kernel = Kernel()
    kernel.add_plugin(plugin)

    proof = await plugin.call_tool(
        "set_cell_contents",
        sheetName="Inputs",
        address="B3",
        value="=0.4",
    )

Use formula strings such as =0.4 when the target MCP host requires each parameter schema to have a single primitive type. Bilig still accepts JSON number, boolean, and null arguments from MCP clients that support union-typed tool parameters. After writing, read the dependent formula cell such as Summary!B3 and reopen the same WorkPaper JSON file before reporting success.

Why This Fits Semantic Kernel

Semantic Kernel agents already treat tools as plugin functions. A WorkPaper MCP server is the right boundary when formula work must be deterministic:

• exact sheet and cell addresses;
• one cell edit per tool call;
• recalculation before returning;
• persisted WorkPaper JSON;
• dependent formula readback before trusting the result;
• restart readback from the persisted WorkPaper JSON;
• no spreadsheet screenshots or cached XLSX formula values.

Use this for quote approval, payout rules, budget gates, import validation, forecast checks, and any agent workflow where spreadsheet formulas are the reviewable business logic.

Boundary

This proves Semantic Kernel can import and call Bilig’s MCP tools. It does not claim full desktop Excel compatibility, Office macro execution, external link refresh, or mutation of arbitrary private spreadsheets without your own WorkPaper JSON file.

Runnable source: examples/semantic-kernel-workpaper-mcp.