CATIA V5 MCP Server

Connect AI agents to Dassault Systemes CATIA V5 via the Model Context Protocol (MCP) — works with Claude, Cursor, Windsurf, Cline, VS Code, Codex and any MCP-compatible client.

The first open-source MCP server for CATIA V5. Drive parametric CAD modeling, measurement, drawing export and COM automation in natural language, from any AI agent that speaks MCP.

What it does

This MCP server exposes 98 tools that let an AI agent:

• Create and manage documents — new Part, Product (assembly), open, save, close

• 2D Sketching — lines, rectangles, circles, arcs, splines, points, constraints

• Part Design — Pad, Pocket, Shaft, Groove, Fillet, Chamfer, Hole, Shell, Draft, Thickness, Patterns (rectangular/circular/user), Mirror

• Generative Shape Design (GSD) — 3D wireframe (points, lines, planes, splines, circles), Multi-sections Surface (loft), Sweep, Extrude, Revolve, Fill, Blend, Offset, Join, Split, Trim, Symmetry, ThickSurface/CloseSurface to solids

• Assembly — add components, Fix/Coincidence/Offset/Angle constraints, move/rotate

• Measurement — distance, inertia, bounding box, parameters

• Knowledgeware — user parameters, formulas, design tables, relations

• Export — STEP, IGES, STL, 3DXML, VRML, screenshots

• View control — set standard views, fit all, capture screenshots

• Drafting — Drawing documents, generative views (axis- or face-driven), projection/section/detail views, 3D-driven dimensions, text and tables (experimental, field-contributed)

• Diagnostics — report the CATIA release and probe which automation APIs the installation exposes

Related MCP server: solidworks-mcp

Requirements

• Windows (COM automation is Windows-only)

• CATIA V5 installed and licensed (R2016+)

• Python 3.10+

• Any MCP client: Claude Desktop, Claude Code, Cursor, Windsurf, Cline, VS Code (Copilot/MCP), Codex CLI, ChatGPT via an HTTP bridge, and others

Compatibility notes (field reports)

• V5R20 (2010): core workflow confirmed working end to end (document management, sketcher, Part Design pad creation, GSD geometrical sets, views, screenshots). An initial report of ShapeFactory.AddNewPad being missing turned out to be a stale pywin32 gen_py cache, not the release: clearing the cache restored the methods (see Troubleshooting). Measurement notes for R20: volume, area and parameters work directly; array-returning measures go through the SystemService.Evaluate detour (proven there for GetPlane; GetCOG and GetPoint use the same route and the same mm coordinate convention). The inertia matrix (Inertia object) and the vertex-sweep bounding box await live confirmation.

• V5-6 2020: full tool surface in active use by contributors.

• Working alongside the agent: a contributor reports dimensioning and testing by hand in the same CATIA session while an agent runs tools in the background, for a whole night, without conflicts. The automation layer is nearly invisible to the interactive user. The one thing to avoid is switching the active document while a tool call is in flight, since most tools resolve "the active document" at call time.

catia_measure_distance accepts tree names (Pad.1, Sketch.2) and indexed topology (Face.N / Edge.N from catia_list_faces / catia_list_edges). The topology path follows a V5R20 field diagnosis (selection Reference property instead of CreateReferenceFromObject, which rejects HSO topology) and awaits live confirmation on real CATIA; reports welcome.

Reports from other releases are welcome, open an issue with your CATIA version and the tool results (the catia_diagnose tool output is the ideal payload).

Quick Install (Recommended)

git clone https://github.com/daiemon12/catia-v5-mcp-server.git
cd catia-v5-mcp-server
bash setup.sh

The script handles everything: dependencies, Claude Desktop configuration, and verification. Using another MCP client? See the per-client setup below.

Manual Installation

1. Clone the repository

git clone https://github.com/daiemon12/catia-v5-mcp-server.git
cd catia-v5-mcp-server

2. Install dependencies

pip install -e .

Or manually:

pip install mcp pywin32

3. Connect your MCP client

The server speaks standard MCP over stdio, so it works with every MCP-compatible client. The command is always the same: python -m catia_mcp (or an absolute path to catia_mcp/server.py).

Edit the config file:

• Windows: %APPDATA%\Claude\claude_desktop_config.json

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "catia-v5": {
      "command": "python",
      "args": ["-m", "catia_mcp"]
    }
  }
}

claude mcp add catia-v5 python -- -m catia_mcp

Add to ~/.cursor/mcp.json (or .cursor/mcp.json in your project):

{
  "mcpServers": {
    "catia-v5": {
      "command": "python",
      "args": ["-m", "catia_mcp"]
    }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "catia-v5": {
      "command": "python",
      "args": ["-m", "catia_mcp"]
    }
  }
}

In VS Code: Cline icon > MCP Servers > Configure, then add:

{
  "mcpServers": {
    "catia-v5": {
      "command": "python",
      "args": ["-m", "catia_mcp"]
    }
  }
}

Add to .vscode/mcp.json:

{
  "servers": {
    "catia-v5": {
      "type": "stdio",
      "command": "python",
      "args": ["-m", "catia_mcp"]
    }
  }
}

Add to ~/.codex/config.toml:

[mcp_servers.catia-v5]
command = "python"
args = ["-m", "catia_mcp"]

ChatGPT only connects to remote MCP servers over HTTP, not to local stdio processes. Expose this server through a stdio-to-HTTP bridge such as mcp-proxy or supergateway on the CATIA machine, then add the resulting URL as a connector in ChatGPT's developer mode. A native HTTP transport is on the roadmap.

Any client that launches stdio MCP servers works: configure a server named catia-v5 with command python and args ["-m", "catia_mcp"], run from a machine where CATIA V5 is installed.

4. Start CATIA V5

Make sure CATIA V5 is running before asking your agent to interact with it. The server will automatically connect to the running instance.

If CATIA V5 is not running, the server will attempt to launch it (requires CATIA to be registered as COM server: cnext.exe /regserver).

Usage Examples

Once configured, just talk to your AI agent:

Create a simple part

"Create a new CATIA part. Draw a 100x60mm rectangle centered at the origin on the XY plane, then extrude it 40mm."

Design a bracket

"Design a mounting bracket: start with a 120x80mm base plate, 5mm thick. Add 4 M6 mounting holes at the corners with 10mm edge distance. Then add two vertical ribs 30mm tall."

Parametric modification

"Show me all parameters of the active part. Then change the pad height to 60mm."

Export for manufacturing

"Export the current part to STEP format at C:/export/bracket.stp and take a screenshot of the isometric view."

Assembly

"Create a new assembly. Add the bracket from C:/parts/bracket.CATPart and the base from C:/parts/base.CATPart. Fix the base, then create a coincidence constraint between the two."

Architecture

catia-v5-mcp-server/
├── catia_mcp/
│   ├── __init__.py
│   ├── __main__.py          # python -m catia_mcp entry point
│   ├── server.py            # MCP Server — tool registration & routing
│   ├── connection.py        # COM connection manager (win32com)
│   └── tools/
│       ├── __init__.py
│       ├── document.py      # Document management (9 tools)
│       ├── sketcher.py      # 2D Sketch tools (11 tools)
│       ├── part_design.py   # 3D Part Design features (18 tools)
│       ├── gsd.py           # Generative Shape Design — wireframe & surfaces (24 tools)
│       ├── assembly.py      # Assembly/Product tools (9 tools)
│       ├── measurement.py   # Measurement & analysis (6 tools)
│       ├── drawing.py       # Drafting: drawings, views, dimensions, text & tables (11 tools)
│       ├── knowledge.py     # Knowledgeware: parameters, formulas, design tables (5 tools)
│       ├── diagnostics.py   # Installation diagnostics (1 tool)
│       └── export.py        # Export & view control (4 tools)
├── pyproject.toml
├── requirements.txt
└── README.md

How it works

AI agent (Claude, Cursor, Windsurf, Cline, ...)
    │
    │ stdio (MCP JSON-RPC)
    ▼
catia_mcp/server.py (MCP Server)
    │
    │ Tool routing
    ▼
catia_mcp/tools/*.py (Tool modules)
    │
    │ win32com.client (COM Automation)
    ▼
CATIA V5 Application

1. The MCP client sends tool calls over stdio

2. The server routes each call to the appropriate tool module

3. Each tool module uses win32com.client to drive CATIA V5 via COM

4. Results (JSON, text) are returned to the agent

Tool Reference

Document Tools (9)

Sketcher Tools (11)

Part Design Tools (18)

Generative Shape Design Tools (24)

Assembly Tools (9)

Measurement Tools (6)

Export Tools (4)

Drafting Tools (11) — experimental

Knowledgeware Tools (5)

Diagnostics (1)

Troubleshooting

Structured tool errors and cancellation

Errors returned by the server boundary for all 98 tools now set MCP isError=true and include structuredContent with ok=false, code, message, operation_id, tool, data, effects, diagnostics, warnings and recovery. The text content contains the same JSON. Clients should inspect isError and the error code rather than matching a plain-text error phrase. Successful text responses and input schemas remain unchanged.

An ordinary exception, including ValueError, does not block the next call. Cancelling a request does not cancel its COM operation: the STA worker finishes that operation before running queued calls. Cancellation does not prove rollback. A modal dialog can still block the worker; resolve it in CATIA before continuing. See runtime behavior and recovery.

"AttributeError" on methods that should exist (AddNewPad, etc.)

A stale pywin32 COM cache is the most common cause, confirmed in the field: methods that genuinely exist stop resolving. Delete the generated bindings cache and restart the server:

%LOCALAPPDATA%\Temp\gen_py\        (or %TEMP%\gen_py\)

Close CATIA and the MCP server first, delete the whole gen_py folder, then restart. Run catia_diagnose to verify which APIs resolve afterwards.

"pywin32 is not installed"

pip install pywin32

This server requires Windows. It will not work on macOS or Linux.

"Failed to connect to CATIA V5"

1. Make sure CATIA V5 is running

2. Register CATIA as COM server: navigate to C:\Program Files\Dassault Systemes\B<version>\<os>\code\bin\ and run cnext.exe /regserver

3. Check that no modal dialog is blocking CATIA

"No active document"

Create or open a document first using catia_new_part or catia_open_document.

COM ByRef array limitations

Some measurement methods may not work with late binding. If you encounter issues, try using pycatia as an alternative backend (contribution welcome).

Contributing

This project is open-source. See CONTRIBUTING.md for guidelines. Contributions welcome:

• Drafting extras: frames and title-block generators, BOM automation

• pycatia backend as alternative to raw win32com

• Tests with COM mocking

• 3DEXPERIENCE CATIA support

Services and support

The server is free and MIT licensed. If your company runs CATIA V5 and wants to go further, the maintainer is available for paid work:

• Custom tools: new MCP tools for your workflows (drawing frames and title blocks, BOM automation, Knowledgeware templates, batch exports).

• Macro modernization: turning legacy VBA/CATScript macros into agent-callable tools, or auditing them before migration.

• Pilot and training: a one-day workshop on agent-driven CATIA automation, followed by a pilot on one of your real parts.

• Priority support: a dedicated channel and response times for teams running the server in production.

Contact: open a discussion on GitHub, join the Discord, or reach the maintainer on LinkedIn. Sponsorship through GitHub Sponsors keeps the free version maintained.

License

MIT

Credits

Inspired by:

• SolidWorks-MCP

• freecad-mcp

• abaqus-mcp-server

• pycatia