zenve3d-mcp

Model parametric CAD parts for Zenve 3D from Claude, or from any other MCP client.

Ask for a box and you get a project — a sketch, its dimensions, an extrude, a timeline you can go back and edit — not a mesh someone has to live with.

Install

// Claude Desktop ▸ Settings ▸ Developer ▸ Edit Config
{
  "mcpServers": {
    "zenve3d": { "command": "uvx", "args": ["zenve3d-mcp"] }
  }
}

macOS on Apple silicon, and nothing else installed: the wheel carries the engine. Zenve 3D itself is a separate install from the App Store — you need it to open what the agent builds, but not to build it.

The four tools

run is the loop, and the loop is the point. A script cannot predict the enumerations a kernel produces — a plate with a hole is two regions — so the agent writes a few lines, runs them, reads back what exists, and writes the next few against the truth instead of a guess. A refusal names its line and still prints everything before it, which is usually what says what the right answer was.

Each call gets a fresh engine and nothing is remembered between them. The script is the state: to change a part, the agent sends it again with the change in it.

Getting the part into the app

The finished script is already on disk: run saves it as ~/Downloads/Zenve/<name>.zcmd and names the path in what it reports back. One file per part, rewritten on every run, so what is in the folder at the end is the finished thing rather than a dozen numbered attempts. Open it with File ▸ New from Script… in Zenve 3D. On iPad, send the file over AirDrop or through Files and import it there.

Ask for an STL alongside it once the part is right, and it lands beside the script ready to slice.

Set ZENVE_OUTPUT_DIR to put those files somewhere else.

Working on the project you have open

Turn on AI mode — the lock beside the panel buttons — and the agent can read your open project with describe and edit it with apply. The edit appears in the viewport straight away and ⌘Z takes the whole thing back, however many commands were in it.

The lock is the whole contract. It stops the app's own editing while an agent is working, which is what keeps the part it is picking faces and edges off from moving underneath it, and it is what puts the app's pointer to the open project where this server can find it. Turn it off and both tools say so instead of guessing.

Nothing lands silently. apply refuses if the lock is off or if the document has moved since the agent last read it, and if the app does not take the edit within ten seconds it withdraws it and says which of the three likely reasons to check.

The projects folder is ~/zenve3d by default — the one the app asks you to pick on first launch. If you picked somewhere else, set ZENVE_SESSION_DIR to it.

Building from a checkout

./scripts/build-zenve3d.sh     # stages the binary and the guide
cd clients/mcp && uv build --wheel

The binary is built against the static OCCT slice in prebuilt/occt/, so it depends on nothing but macOS — checked by the build script rather than assumed.