pyeonclient 0.2.0

Nanobind bindings to the eOn C++ client (Matter, Parameters, Potential, Jobs)

Install

pip install pyeonclient
pip install 'pyeonclient[ase]'  # optional

pyeonclient

Nanobind-only bindings for the eOn C++ client library (libeonclib).

No pybind11. This module supersedes the old unused with_pybind11 option.

ABI policy

Interpreter	Extension build
CPython ≥ 3.12 (GIL)	Stable ABI (abi3) — Py_LIMITED_API=0x030C0000
CPython ≥ 3.13 free-threaded (Py_GIL_DISABLED)	Free-threaded (NB_FREE_THREADED); stable ABI not available yet

Meson detects free-threaded vs GIL builds from sysconfig.Py_GIL_DISABLED and sets exactly one of the two modes (same rule as nanobind’s CMake STABLE_ABI + FREE_THREADED pair).

Package layout

client/python/
  meson.build              # -Dwith_pyeonclient=true
  pyeonclient/
    __init__.py            # re-exports
    bridge.py              # Structure <-> Matter (server)
  bind/
    module.cpp             # NB_MODULE(_core, ...)
    bind_*.cpp
    eigen_numpy.hpp

Artifact: pyeonclient/_core*.so (or _core*.abi3.so).

Build

# needs nanobind>=2.2 on the build Python
meson setup build -Dwith_pyeonclient=true
meson compile -C build
pytest tests/test_pyeonclient_matter.py -v

Design

Bottom-up surface: Matter, Parameters, Potential, enums/I/O — not a thin job wrapper. Jobs and communicators layer on Matter later. .con I/O uses ConFileIO / readcon-core (same path as eonclient).