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

adaptive-router-core
0.1.4

This version was deleted from PyPI around 2025-12-22. Installing fails with:
$ pip3 install adaptive-router-core==0.1.4 ERROR: Could not find a version that satisfies the requirement adaptive-router-core==0.1.4