Kepler is a tool to generate ePub eBooks from Safari Books Online.

1. git clone https://github.com/Sneezry/Kepler.git
2. Open chrome://extensions/ in Chrome
3. Enable developer mode
4. Load unpackaged extension
5. Select Kepler folder

1. Open Safari Books Online and login your account
2. Open the book you want to convert (such as https://www.safaribooksonline.com/library/view/learning-typescript/9781783985548/)
3. Click Kepler icon on top right corner in your browser
4. Wait and save ePub eBook

1. Download and install Kindle Previewer
2. Open the generated ePub file in Kindle Previewer
3. Export mobi or azk file
4. Import the file into Kindle

1. Download KindleGen
2. ./kindlegen <epub-file-name>

I haven't tested these projects, but just show them here in just case you may need them if this project cannot help you.

1. https://github.com/lorenzodifuccia/safaribooks