helenkwok/openbim-mcp

Fragment MCP Server

A Model Context Protocol (MCP) server for working with Building Information Modeling (BIM) files. This server provides tools to convert IFC files to fragment format, load fragments, and query BIM data by category.

Features

• IFC to Fragment Conversion: Convert Industry Foundation Classes (IFC) files to the open and efficient fragment format
• Fragment Loading: Load and work with pre-converted fragment files
• Category-based Querying: Fetch BIM elements by category (e.g., walls, doors, windows) with configurable attributes and relations

Tools

convert-ifc-to-frag

Converts an IFC file to a .frag file format for efficient processing.

Parameters:

• inputPath (string): Full path of the IFC file to convert
• outputPath (string): Full path where the output .frags file will be saved

Example:

Input: /path/to/building.ifc
Output: /path/to/building.frag

load-frag

Loads a .frag file into memory for querying.

Parameters:

• filePath (string): Full path of the .frag file to load

fetch-elements-of-category

Fetches elements of a specified IFC category from loaded fragments.

Parameters:

• category (string): Category name (e.g., "IFCWALL", "IFCDOOR", "IFCWINDOW")
• config (object): Configuration for fetching elements with the following structure:
  • attributesDefault (boolean): Include default attributes
  • attributes (array): List of specific attributes to include
  • relations (object): Relation configuration
    • HasAssociations: Include association relations
    • IsDefinedBy: Include definition relations

Dependencies

• @modelcontextprotocol/sdk: MCP server framework
• @thatopen/fragments: Fragment processing library
• web-ifc: IFC file processing
• zod: Schema validation

Installation

1. Install dependencies:

pnpm install

1. Run the server:

node main.ts

Claude Desktop Integration

To use this MCP server with Claude Desktop, add the following configuration to your Claude Desktop settings file:

Configuration

1. Open Claude Desktop settings
2. Navigate to the MCP servers configuration
3. Add the following JSON configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "/path/to/your/models/directory"
      ]
    },
    "bim": {
      "command": "npx",
      "args": [
        "-y",
        "tsx",
        "/path/to/your/openbim-mcp/main.ts"
      ]
    }
  }
}

Prerequisites for Claude Desktop

• Node.js must be installed and accessible via npx
• The tsx package should be available (install globally with npm install -g tsx if needed)
• Both the filesystem and bim servers need to be configured for full functionality

Usage Workflow

1. Convert IFC to Fragment: Use convert-ifc-to-frag to convert your IFC file to the efficient fragment format
2. Load Fragments: Use load-frag to load the fragment file into memory
3. Query Elements: Use fetch-elements-of-category to retrieve specific building elements by their IFC category

Supported IFC Categories

Common categories you can query include:

• IFCWALL - Walls
• IFCDOOR - Doors
• IFCWINDOW - Windows
• IFCSLAB - Slabs/Floors
• IFCBEAM - Beams
• IFCCOLUMN - Columns
• IFCSPACE - Spaces/Rooms

Requirements

• Node.js
• File system access for reading IFC files and writing fragment files
• Compatible with Model Context Protocol clients

Author

Helen Kwok