This is a small python app with optional webUI. It is intended to be run locally. It can be run with Docker (cookie autodetection will not work).

It allows you to download a single substack, either entirely or partially, and saves the output to an epub file, which can be easily transferred to Kindle or other reading devices.

This is admittedly a "vibe coded" app made with Claude Code and a few hours of iterating, but I've already found it very useful for myself.

It supports both free and paywalled posts (if you are a paid subscriber to that creator).

You can order the entries in the epub by popularity, newest first, or oldest first, and also limit to a specific number of entries, if you don't want all of them.

You can either provide your substack.sid cookie manually, or you can have it be autodetected from most browsers/operating systems.