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

fastseqio
0.0.1

This version was deleted from PyPI around 2025-09-12. Installing fails with:
$ pip3 install fastseqio==0.0.1 ERROR: Could not find a version that satisfies the requirement fastseqio==0.0.1
View other deleted versions of fastseqio

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/2025-09-11/ \ fastseqio==0.0.1
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Or, download files manually

And install manually via pip:
fastseqio-0.0.1-py3-none-any.whl (122.3KB)
fastseqio-0.0.1.tar.gz (121.2KB)