NX MCP
NX MCP connects an agent to Siemens NX with 16 typed tools for parts, sketches, extrusions and STEP export.
- 173 ★ on the repository
- Last commit
- MIT
Extended access
Why this level
- The agent creates and changes parts in a local Siemens NX while a bridge executes NXOpen calls inside its process.
Install
- Works in
Manual install
git clone https://github.com/DreamEnding/NX_MCP.gitFirst installation command from the README, for PowerShell. Then a virtual environment and `pip install -e .`.
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- The agent creates and changes parts in a local Siemens NX while a bridge executes NXOpen calls inside its process.
This is third-party code. Review the repository files before installing.
What it does
NX MCP, a Python server, links an MCP client to a local Siemens NX. The agent creates, opens and saves parts, draws sketches with lines and rectangles, extrudes solids, lists sketches, bodies and features, undoes operations and fits the view. A finished model exports to STEP. There are 16 tools, and `nx_status` reports connection state. The server runs outside NX while a local bridge executes NXOpen calls inside the NX process. The bridge comes in two kinds: C# for an open NX2206 window and a batch Python one for NX2506. They talk over authenticated JSON-RPC on a loopback address.
Who it is for. Designers and CAD automators on Windows with Siemens NX installed who want an agent for routine part operations.
Good fit when
- A series of simple parts has to be made from a sketch and extruded from a table of sizes.
- An agent is asked to check which sketches and bodies exist in an open part.
- Models are exported to STEP for exchange with a subcontractor.
- An operation in the model has to be rolled back and the agent undoes it through `nx_undo`.
Not a fit when
- The system is not Windows or NX is not installed locally, and without a bridge the server draws nothing.
- Complex operations such as mates and measurements are needed, and the 16 tools do not cover them.
- A release-grade confirmed version is required, while the project is still in development.
Example request
Call `nx_status`, create a part, draw a 40 by 20 mm rectangle on a new sketch, extrude it 10 mm and export STEP.MCP
- Transport
- stdio
- Authentication
- not required
Environment variables
NX_MCP_WORKSPACErequired- Workspace folder with NX parts
NX_MCP_STATE_DIRrequired- State directory shared by server and bridge
Limitations
Version `0.2.0.dev0` is marked a preview: acceptance of one candidate on both NX2206 and NX2506 is not finished. Windows, a local Siemens NX, Python 3.10, PowerShell 7 and Git are required. The C# bridge must be built against your NX assemblies and needs an NX Open .NET author license for an unsigned DLL, otherwise the library is signed with `SignDotNet.exe`. Work in a test workspace. Run one bridge per state directory. The 34 legacy tools are hidden and unverified.
How to disable. Remove the `nx-mcp` block from the client configuration and stop the bridge: the C# bridge unloads by running it again in NX, and the batch one stops on a stop file. Delete the `~/.nx-mcp` state directory by hand.
FAQ
What does `nx_status` return when connected?
`connected: true`, the NX version and `bridge_implementation` (`python_batch` or `csharp_gui`). With no work part, `active_part` and `units` are `null`.
What does the NX_BRIDGE_UNAVAILABLE error mean?
The bridge is not running or the client and bridge use different state directories. Check that `NX_MCP_STATE_DIR` is identical and an absolute path.
Which units does geometry use?
The work part's native units. `nx_status.units` returns `mm` or `inch`; if it is `null`, confirm units before modeling.
Which bridge should I choose?
The C# GUI bridge runs in an open NX2206 window and keeps the interface available. The batch Python bridge starts through `run_journal.exe`, blocks the session and was checked on NX2506.
Does macOS work?
No. The README requires Windows and a local Siemens NX.
Discussion
No questions or reviews yet.
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Comparison with similar tools
Cards that share the main search query, and how they differ.
| Tool | Official | Authentication | Repository stars | Main difference |
|---|---|---|---|---|
| NX MCP (this card) | no | not required | 173 | |
| Nx MCP | yes | not required | 1,415 | belongs to the Nx build system for JavaScript monorepos; NX MCP drives the Siemens NX CAD system |
| FreeCAD MCP | no | not required | 3,310 | drives open-source FreeCAD; NX MCP works with commercial Siemens NX through an NXOpen bridge |
README in short
The server installs from a clone into a virtual environment, then one of two bridges starts in NX and the client connects through an `mcpServers` block with the absolute Python path. Tools have typed inputs and structured results.