FreeCAD MCP connects Claude Desktop to FreeCAD, the open-source parametric CAD application. The neka-nat/freecad-mcp repository can create documents, create and edit objects, delete objects, execute Python code in FreeCAD, insert parts from the FreeCAD library, retrieve views, list objects, and run FEM analysis through CalculiX. It is one of the more adopted CAD connectors in this selection, with 1902 stars and 256 forks at the GitHub check on August 26, 2026.
For an architecture firm, FreeCAD MCP does not play the same role as Revit MCP or Archicad MCP. FreeCAD is not the primary BIM tool for most French firms, but it can be useful for prototyping a part, explaining parametric modeling, generating simple geometry, or testing open-source automation without a commercial license. The connector is therefore most interesting as an AI-controlled CAD laboratory.
Contents
- What FreeCAD MCP does
- Installation and architecture
- Useful capabilities
- Comparison with BIM and CAD MCPs
- Security, remote access, and limits
- Educasium's position
- Sources and next reading
What FreeCAD MCP does
Key point: FreeCAD MCP gives Claude an action interface for FreeCAD, with object creation, editing, view capture, parts library access, and Python execution. Its strength is open-source flexibility; its limit is the technical level required.
Exposed tools
The README lists create_document, create_object, edit_object, delete_object, execute_code, insert_part_from_library, get_view, get_objects, get_object, get_parts_list, get_rpc_status, and run_fem_analysis. Tools that return screenshots accept include_screenshot and view_name to suppress or orient the image. The only_text_feedback mode can globally disable screenshots to save tokens.
This surface is broader than a simple shape generator. The assistant can inspect the document, modify an existing object, insert a part from the official FreeCAD-library, or run FEM analysis on an existing FemAnalysis. For training, this is a useful way to show the difference between a parametric object, a view capture, and a Python script.
Python inside FreeCAD
execute_code is the most powerful tool. It runs Python inside FreeCAD, which opens almost the entire FreeCAD API surface. This is exactly what makes the connector useful for advanced workflows, but also what requires testing discipline.
A poorly scoped instruction can create broken objects, block the GUI thread, or modify a document in a way that is hard to review. The README warns that after an execute_code exception on a FreeCAD development build, new FeaturePython objects should be inspected before being mutated or deleted, because an object missing its required Proxy can wedge FreeCAD's GUI thread.
Installation and architecture
Key point: FreeCAD MCP combines a local FreeCAD add-on and an MCP server launched with uvx or uv. Adding one line to Claude Desktop is not enough.
FreeCAD add-on
The README gives add-on folders for Windows, macOS, and several Linux distributions. Installation means copying addon/FreeCADMCP into FreeCAD's Mod folder, then restarting FreeCAD. The user then selects the MCP Addon workbench and starts the RPC server from the FreeCAD MCP toolbar.
The RPC server can also start automatically if Auto-Start Server is enabled in the FreeCAD MCP menu. The setting is saved to freecad_mcp_settings.json and persists across sessions. That is useful for a recurring workstation, but during a pilot manual startup is preferable so users know when the tool is active.
MCP server and Python requirements
Claude Desktop configuration uses uvx with the freecad-mcp argument. The verified pyproject shows a freecad-mcp package at version 0.1.22, MIT license, Python 3.12 or newer, and mcp plus validators dependencies. For developers, the README also proposes running through uv from a local clone.
This is simpler than connectors requiring Visual Studio or Civil 3D DLLs, but it remains technical. The add-on must be installed in the right place, the FreeCAD-side RPC server must be started or auto-started, and the Claude-side MCP client must be configured. An error at any of those three levels breaks the connection.
Useful capabilities
Key point: FreeCAD MCP is relevant for prototyping, teaching, and automating simple parametric objects. It does not replace a firm's BIM workflow.
Modeling and parts library
create_object, edit_object, and delete_object cover direct manipulation of FreeCAD objects. insert_part_from_library and get_parts_list add a link to FreeCAD-library, allowing existing parts to be inserted instead of rebuilding everything. For a teaching workshop, this makes demonstrations easier: create a document, add a volume, change its parameters, insert a part, then capture the view.
In a firm, this scope can help explore details, objects, simple assemblies, or geometry variants. It is not designed as a substitute for a full Revit, Archicad, or Rhino model. Its value mainly comes from openness: FreeCAD and Python make it easier to understand what automation is actually doing.
FEM and CalculiX
run_fem_analysis launches the CalculiX solver on an existing FemAnalysis and returns summary results: maximum von Mises stress, maximum displacement, node count, and working directory. The README says it auto-creates a SolverCcxTools if the analysis has none, and points to a cantilever_fem.py example.
This capability is interesting but should not be oversold. It can help demonstrate a calculation chain or test a simple part, but it does not replace qualified structural analysis. Any FEM result should remain under the control of a competent engineer, especially if a design decision depends on it.
Comparison with BIM and CAD MCPs
Key point: FreeCAD MCP is the most open and experimental CAD connector in this series. It is less domain-specific than a Revit MCP, but more accessible for exploring programmable CAD.
| Option | Natural use | Main strength | Limit to watch |
|---|---|---|---|
| FreeCAD MCP | Prototyping and automating FreeCAD | Open source, Python, parametric objects, screenshots | execute_code and firm workflow maturity |
| Revit MCP | Acting on a building BIM model | Ready-to-use BIM tools | Revit dependency and write governance |
| AutoCAD MCP | Automating AutoCAD LT and DXF | AutoCAD and ezdxf backends | DWG/DXF-centered, less parametric |
FreeCAD MCP versus Revit and Archicad
The Revit MCP and Archicad MCP target BIM software used directly in firm production. FreeCAD MCP targets a more general open-source application. That makes it less immediately compatible with common firm deliverables, but more interesting for learning automation logic.
A Revit or Archicad firm should not migrate workflows because of FreeCAD MCP. It can, however, use it as a test environment to understand how an assistant creates, edits, and inspects CAD objects without exposing a client model.
FreeCAD MCP versus AutoCAD MCP
The AutoCAD MCP is more oriented toward drawing, layers, blocks, annotations, and DXF. FreeCAD MCP is more oriented toward parametric objects, Python scripts, screenshots, and simple simulation. They therefore do not serve the same use case.
If the goal is to produce or edit a DWG/DXF drawing, AutoCAD MCP is more natural. If the goal is to explore open-source parametric geometry or show how Python drives CAD, FreeCAD MCP is more pedagogical.
Security, remote access, and limits
Key point: FreeCAD MCP starts locally by default, but can accept network connections if the user enables them. That option must be treated carefully.
Local and remote connections
By default, the RPC server does not accept remote connections and listens on localhost. The README documents a Remote Connections option that binds the server to 0.0.0.0 on restart, with a list of allowed IP addresses or CIDR subnets. 127.0.0.1 remains the default and invalid entries are rejected.
For a firm, the rule should be simple: stay on localhost during tests. Remote connections should only be enabled when the need is clear, with a controlled network, limited allowlist, and IT validation. A server that can execute Python inside FreeCAD should not be broadly exposed.
GUI dispatch and broken objects
The README states that if a GUI-thread operation exceeds its timeout after it has started, the bridge returns GUI_DISPATCH_STUCK and rejects later GUI operations. get_rpc_status then identifies the operation still running. FreeCAD GUI work cannot be force-cancelled safely; if status does not return to healthy after the operation finishes, FreeCAD should be restarted.
This limit matters in production. It means a bad script is not always fixed by a simple retry. Save, test in a separate document, and avoid chaining heavy operations without intermediate checks.
Educasium's position
Key point: Educasium can use FreeCAD MCP as a learning environment, but should not present it as already validated in a client firm.
Available experience
Educasium has not yet deployed FreeCAD MCP in a client firm or measured verified time savings on a real CAD workflow. This page relies on the verified README, pyproject, examples, and GitHub metadata. It describes an open-source capability, not a case study.
Its teaching value is strong. FreeCAD MCP shows the relationship between prompt, parametric object, screenshot, Python code, and result. It is also suited to workshops where the goal is to avoid a proprietary license or confidential model.
Hypothetical implementation
Hypothetical implementation. For an Educasium pilot, the first step would be installing the FreeCADMCP add-on, starting RPC manually, and connecting Claude Desktop through uvx. First tests should stay with create_document, create_object, get_objects, get_view, and edit_object with include_screenshot enabled, so every step can be visually checked.
execute_code and run_fem_analysis would come later, on test documents and short scripts. Remote connections would remain disabled. The success criterion would be a reproducible sequence: create a simple object, edit a parameter, capture a view, then explain what the code did.
Sources and next reading
Key point: the information on this page comes from the GitHub repository and was verified on August 26, 2026. Versions, tools, screenshot parameters, remote connections, and Python requirements come from the README and pyproject.
What to read next
For building BIM workflows, compare FreeCAD MCP with the Revit MCP and Archicad MCP. For 2D CAD flows, also read AutoCAD MCP and CAD-MCP.
To build a broader adoption strategy, read the AI software comparison for architects and the Mastering AI in Architecture course.