Frequently Asked Questions

Can everyone use it?

Flatlib is open-source software so everyone is free to install and use it. However, since it is a programming library, some people may not be particularly inclined to use it since it requires some learning.

So is it not a end-user tool?

Flatlib should really be seen as a traditional astrology software without a graphical user interface. Therefore, it is really powerful, since users can experiment without the “chains” of a graphical user interface.

How can I install it?

Documentation is still scarce, but I hope to improve it in the future. You should install the latest Python 3 (3.4) and grab the flatlib package with pip3 install flatlib. This will install flatlib and its dependencies.

Is there a project page?

You can check the code and simple documentation in the github page at

Are there any sample code?

There’s a “recipes” folder with some source code at You can start with “” which is at

Can I use it on my own work?

Absolutely yes, you are free to use it in your own projects. The flatlib source code is released under an MIT License, which allows it to be used also on commercial projects. There is a caveat though: flatlib uses the swiss ephemeris which is licensed GPL. Therefore, if you want to use flatlib in your commercial projects, you must adhere to the GPL license or buy a Swiss Ephemeris commercial license.

Why are you open-sourcing flatlib?

I really want to help push forward data-driven research in astrology. That is only possible with a strong community of researchers and good tools, so there was no point in keeping flatlib hidden on my hard disk. Flatlib is also a good tool for talking about astrology techniques. Someone can always point to the source code to explain how things can be done.

Can I contribute to the project?

I accept contributions such as code and documentation, although I suggest to wait a while since things are not stable yet. The best contribution for now is to spread the news about the existence of this project.