nxopen-mcp

MCP (Model Context Protocol) server that exposes the Siemens NX / NXOpen .NET API database to AI coding tools such as Claude Code, Cursor, and Copilot.

Requirements

• Node.js ≥ 18
• A running cad-backend instance with an NXOpen SQLite index loaded

Usage

With Claude Code

# Set the backend URL (default: http://127.0.0.1:9222)
set NXOPEN_BACKEND_URL=http://your-server:9222

claude mcp add --transport stdio --scope local nxopen -- npx nxopen-mcp
# or with explicit backend
claude mcp add --transport stdio --scope local nxopen -- npx nxopen-mcp --backend http://your-server:9222

Version auto-detection

The server detects the NX version in this order:

1. NXOpen.dll ProductVersion found in the project tree
2. .nx-version file in the project root (written automatically after first use)
3. Backend has exactly one version loaded → auto-selected
4. Prompts the user — Claude will ask which version to use, then call nx_set_version

Once set, the version is saved to .nx-version and reused in future sessions.

Tools

| Tool | Description | |---|---| | nx_set_version | Set the NX version for this project (persisted to .nx-version) | | nx_index_status | Status of loaded NXOpen SQLite indexes | | nx_get_project_context | Detect NXOpen C# project context | | nx_refresh_project_context | Re-scan project and verify index | | nx_list_nx_projects | List C# projects with NXOpen references | | nx_hybrid_search_api | Natural-language API search | | nx_get_type | Look up a type by full name | | nx_get_members | List members of a type | | nx_get_method_signature | Get method overload signatures | | nx_validate_symbols | Validate NXOpen symbols in C# code |

Backend

See cad-backend on PyPI for setup instructions.

License

MIT