Bc Webclient MCP Server

Overview

Install

VSCode

Click the badge. VSCode opens, prompts to add the server, and writes to your user mcp.json.

You will still need to set BC_BASE_URL, BC_USERNAME, and BC_PASSWORD in the entry's env block. VSCode opens the file for you to edit.

Workspace: create .vscode/mcp.json:

{
  "servers": {
    "business-central": {
      "command": "npx",
      "args": ["-y", "business-central-mcp"],
      "env": {
        "BC_BASE_URL": "http://your-bc-server/BC",
        "BC_USERNAME": "your-user",
        "BC_PASSWORD": "your-password"
      }
    }
  }
}

Claude Code

claude mcp add business-central \
  -e BC_BASE_URL=http://your-bc-server/BC \
  -e BC_USERNAME=you \
  -e BC_PASSWORD=secret \
  -- npx -y business-central-mcp

Scope it to the current project with --scope project. See claude mcp --help for scoping options.

Claude Desktop

1. Download the latest .dxt from Releases.
2. Double-click. Claude Desktop opens Settings → Extensions and prompts for BC URL, username, and password.
3. Restart Claude Desktop.

Edit claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "business-central": {
      "command": "npx",
      "args": ["-y", "business-central-mcp"],
      "env": {
        "BC_BASE_URL": "http://your-bc-server/BC",
        "BC_USERNAME": "your-user",
        "BC_PASSWORD": "your-password"
      }
    }
  }
}

Restart Claude Desktop.

Configuration

What can it do?

How it works

This server speaks BC's internal WebSocket protocol directly -- the same protocol the browser-based web client uses. It was reverse-engineered from decompiled BC server assemblies. No OData endpoints, no SOAP services, no Selenium.

One WebSocket connection per session. All operations serialized through a promise queue. BC27 and BC28 are wire-compatible.

LLM (Claude / Copilot / etc.)
   |
   v   MCP (stdio or HTTP)
business-central-mcp
   |
   v   WebSocket + JSON-RPC
BC Web Service Tier (BC27 / BC28)
   |
   v   internal calls
BC Server

bc_open_page returns the page as a flat list of sections:

{
  "pageContextId": "session:page:21:abc",
  "pageType": "Card",
  "caption": "Customer Card",
  "isModal": false,
  "sections": [
    { "sectionId": "header",                       "kind": "header",  "fields": [...], "actions": [...] },
    { "sectionId": "factbox:Customer Statistics",  "kind": "factbox", "fields": [...] }
  ]
}

Each section carries its own content shape:

• Card-style (header on Card pages, factbox, requestPage): fields[] and (for header) actions[]
• List-style (lines on Documents, header on List pages, repeater subpages): rows[] and totalRowCount
• Cue tiles (Role Center hosted CardParts): cues[] with each tile's name, value, groupCaption, synopsis, hasAction. Drill down with bc_execute_action { section, cue }.

bc_read_data returns a single Section for the requested sectionId (defaults to "header"). The section ID for a FactBox or subpage comes from the bc_open_page response.

• Automatic reconnect with exponential backoff after session death
• Handles BC's ~15s NTLM auth slot hold after crashes
• Auto-dismisses license popups on fresh databases
• Invoke timeout kills hung sessions and triggers recovery
• Auto-recovery from LogicalModalityViolationException mid-session: reconciles the modal stack and retries transparently; falls back to session reset when BC keeps a confirm dialog sticky

Key files

Development

git clone https://github.com/SShadowS/business-central-mcp
cd business-central-mcp
npm install
npm run start:stdio-direct   # Run from source
npm test                     # 284 unit + protocol tests
npm run test:integration     # 111 integration tests against real BC (requires running BC server)

Roadmap

OAuth, Cursor support, an interactive init wizard, and a few protocol gaps. See ROADMAP.md for the full list and priorities.

Author: Torben Leth (sshadows@sshadows.dk) License: MIT (see LICENSE)