I´m currently starting to build a self expanding factory with the Space Age DLC and I´m wondering if it´s possible to create new space platforms via logic and then paste a ship blueprint on that platform automatically while also being able to paste down blueprints to a planets surface. It would be awesome if it would be possible to fully complete Space Age just with the smallest blueprint at the beginning so I´d love to try.

Sorry for posting in a threat, first time creating a new threat on the MP

I’ve already been asked about this.
The API allows you to build a blueprint on another surface (a ship or a planet). But unfortunately, I still haven’t figured out how to use signals to determine the target surface (or, more precisely, the format of such signals).

I’ve already been asked about this.
The API allows you to build a blueprint on another surface (a ship or a planet). But unfortunately, I still haven’t figured out how to use signals to determine the target surface (or, more precisely, the format of such signals).

Would I be correct in saying the problem isn't the other planets, but the ships/space platforms, because there's no user-facing identity for those surfaces that the user would have to set to define which surface to build on?

Yes.
I can interpret the signals as a <surface number> + <absolute coordinates X and Y> (this will work not only for the deployer but also for the scanner).
But I haven’t yet figured out how to make a convenient way to link surfaces with numbers. Surfaces are dynamically created and deleted (I haven’t checked how this looks from the mod’s perspective).