DWG MCP Server — Claude Code MCP server: features and setup
Connects DWG and DXF CAD files to LLMs without local CAD suites. Lets agents inspect layers, search entities, and render layout views.
claude mcp add --env DWG_MCP_ALLOWED_ROOTS=<DWG_MCP_ALLOWED_ROOTS> --transport stdio dwg-mcp-server -- npx -y @dmytro-prototypes/dwg-mcp-serverWhat DWG MCP Server does
The server exposes DWG and DXF drawings to MCP clients using LibreDWG under the hood. Opening a file spawns a dedicated Rust worker process. The worker indexes layers, entities, and blocks directly in memory. This one-time indexing step avoids rescanning the drawing for subsequent queries.
Source drawing files stay untouched on disk. Any property edits apply solely to the memory state and disappear when the session terminates. Models can filter elements by handle, inspect geometry, and export model views or paper layouts to SVG or PNG.
Client access requires explicit directory permissions. When an AI client fails to supply MCP root paths, drawings remain inaccessible until declared in DWG_MCP_ALLOWED_ROOTS.
What it helps with
- inspect layer hierarchies and block structures in DWG files
- export drawing views or paper layouts into SVG and PNG formats
- query specific CAD entities using handles and property filters
- review drawing geometry without launching heavy CAD software
Example prompts for the agent
- Open
building_plan.dwgand list all entity types present in the file - Render the primary paper-space layout from
elevation.dxfas an SVG - Find all block references located on the
DOORSlayer
How to install DWG MCP Server
Platform CLI
claude mcp add --env DWG_MCP_ALLOWED_ROOTS=<DWG_MCP_ALLOWED_ROOTS> --transport stdio dwg-mcp-server -- npx -y @dmytro-prototypes/dwg-mcp-serverReplace <…> with your own values
Platform CLI
codex mcp add dwg-mcp-server --env DWG_MCP_ALLOWED_ROOTS=<DWG_MCP_ALLOWED_ROOTS> -- npx -y @dmytro-prototypes/dwg-mcp-serverReplace <…> with your own values
Config file
{
"mcpServers": {
"dwg-mcp-server": {
"command": "npx",
"args": [
"-y",
"@dmytro-prototypes/dwg-mcp-server"
],
"env": {
"DWG_MCP_ALLOWED_ROOTS": "<DWG_MCP_ALLOWED_ROOTS>"
}
}
}
}Replace <…> with your own values
Config file
{
"servers": {
"dwg-mcp-server": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@dmytro-prototypes/dwg-mcp-server"
],
"env": {
"DWG_MCP_ALLOWED_ROOTS": "<DWG_MCP_ALLOWED_ROOTS>"
}
}
}
}Replace <…> with your own values
Platform CLI
gemini mcp add -e DWG_MCP_ALLOWED_ROOTS=<DWG_MCP_ALLOWED_ROOTS> dwg-mcp-server npx -y @dmytro-prototypes/dwg-mcp-serverReplace <…> with your own values
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about DWG MCP Server
How to install DWG MCP Server in Claude Code?
Run claude mcp add dwg-mcp-server -- npx -y @dmytro-prototypes/dwg-mcp-server. If your environment requires manual folder paths, pass the environment variable: claude mcp add --env DWG_MCP_ALLOWED_ROOTS=<DWG_MCP_ALLOWED_ROOTS> --transport stdio dwg-mcp-server -- npx -y @dmytro-prototypes/dwg-mcp-server.
Does the server overwrite or modify local DWG files?
No. Source files remain strictly read-only on your storage drive. Property edits stay in system memory and vanish as soon as the session closes.
Why configure the DWG_MCP_ALLOWED_ROOTS variable?
Certain MCP tools, such as Codex, do not provide folder roots over stdio. Setting DWG_MCP_ALLOWED_ROOTS tells the server which drawing folders it can safely access.
