You're looking at StableBuild's Deleted PyPI mirror - where we index all deleted packages from the Python package registry.

opensim-py
0.0.0b0

This version was deleted from PyPI around 2025-07-03. Installing fails with:
$ pip3 install opensim-py==0.0.0b0 ERROR: Could not find a version that satisfies the requirement opensim-py==0.0.0b0
View other deleted versions of opensim-py

Install through StableBuild

You can install this package from StableBuild's PyPI snapshots from before the version was deleted:
pip3 install \ -i https://YOUR_API_KEY.pypimirror.stablebuild.com/2025-07-02/ \ opensim-py==0.0.0b0
Sign up for StableBuild to get an API key (it's free and takes <60 seconds!)

Or, download files manually

And install manually via pip:
opensim_py-0.0.0b0-py3-none-any.whl (712.1KB)
opensim_py-0.0.0b0.tar.gz (703.8KB)