STEPhen - STEP output job automation tool

Copyright (c) 2026 Antmicro

This is a simple command-line output job automation tool for STEP file assemblies based on cadquery library. It allows to decompose a single complex STEP file into sub-parts and generate a mechanical Bill of Materials (BOM) and position files. It also enables recreating complex STEP models from single parts.

Features

• generation of BoM files containing mechanical components of the assembly in CSV and HTML formats
• generation of position files containing coordinates and rotations of each mechanical components in 3D space
• exporting assembly components as separate STEP files
• generation of SVG previews of each assembly component
• exporting assembly back from component STEP files and its position file

Installation

While in reposistory, use pipx to install stephen:

pipx install .

Usage

To process an assembly using stephen, provide it with a path to a input file (assembly STEP or STEPhen-generated PnP CSV file) and specify output options:

stephen PATH/TO/INPUT --OPTIONS

Usable options:

--bom   -b    Export BOM in CSV format      
--html  -h    Export BOM in HTML format                               
--pos   -p    Export part positions in CSV format
--all   -a    Export entire assembly STEP
--step  -s    Export STEP files for assembly components
--svg   -S    Export SVG files for assembly components

You can test STEPhen using the model located in example/ directory:

stephen example/hen.step --step --svg --bom --html --pos

License

The stephen utility is licensed under the Apache-2.0 license.