How would you build this app?

Hello

I’m trying to figure out how to build an app exactly like this one https://create.thenightsky.com/en/design

Specifically the star map. I know they getting their star catalog from the European Space Agency’s Hipparcos as specified here
https://help.thenightsky.com/article/aum6l38cms-is-the-star-map-accurate

But how? I couldn’t find any API to query some sort of star chart based on dates.

Can you please help me find out how they do that?

Thanks

They probably created their own API using various data sources. You could search through (which I did not do) the 20+ source files in their code and look for calls to some kind of API, to validate this assumption.

You could try to contact them and ask if they use an API.