Project Structure

A ChimeraX bundle project generated by echi init has the following structure:

my-tool/
├── pyproject.toml      # Bundle metadata and build config
├── src/
│   ├── __init__.py     # Bundle initialization
│   └── cmd.py          # Command implementation (varies by bundle type)
├── tests/              # Test files (for echi test)
│   └── test_*.py       # pytest test modules
├── scripts/
│   └── smoke.cxc       # Smoke test script
└── README.md

Key Files

pyproject.toml

The central configuration file for your bundle. Contains:

• Bundle metadata (name, version, description)
• ChimeraX-specific configuration (commands, tools, etc.)
• Build system configuration

src/

Source code for your bundle. The layout depends on the bundle type:

Bundle Type	Main Source File
command	src/cmd.py
tool, tool-html	src/tool.py
format	src/open.py
fetch	src/fetch.py
selector	src/selector.py
preset	src/preset.py
cpp	src/chimerax/<package>/cmd.py + _extension.cpp

scripts/smoke.cxc

A ChimeraX command script for quick smoke testing. Run with:

echi test --smoke

tests/

Directory for pytest test files. Run with:

echi test