# smlibpy

> smlibpy is a Python library for 3D CAD modeling on SMLib, the open-source NURBS kernel. It comes with an MCP server: agents write Python with smlibpy, the server runs it, shows the model in a live viewer on 127.0.0.1, renders pictures and saves STEP, STL and glTF files. It needs no account and runs on the user's machine.

## Install the MCP server

The server is started with uv (https://docs.astral.sh/uv/). If `uvx` is missing, install uv first.

Claude Code, with the plugin (the server and a skill):

    claude plugin marketplace add awv-informatik/smlibpy
    claude plugin install smlibpy@smlibpy

Claude Code, the server only:

    claude mcp add smlibpy --scope user -- uvx --from "smlibpy[mcp]" smlibpy-mcp

Other hosts (Claude Desktop, Cursor, VS Code, Codex, OpenCode) take the same command. As JSON:

    { "mcpServers": { "smlibpy": { "command": "uvx", "args": ["--from", "smlibpy[mcp]", "smlibpy-mcp"] } } }

After installing, tell the user to start a new session and ask for a part.

## Use

- Read the guides first: docs(["SKILL", "recipes/modeling", "recipes/verification"]).
- Build with run_script in steps; check volume, bounding box and is_valid() after each; look with snapshot(view="sheet").
- Deliver with save(format="step", path=...).

## Docs

- Documentation: https://smlibpy.classcad.ch/docs/
- Agents (MCP): https://smlibpy.classcad.ch/docs/mcp
- Source: https://github.com/awv-informatik/smlibpy