[saagarjha]

> both Marta API and a plugin need to be built with the same version of Swift

As far as I’m aware, this isn’t a problem, since your communicating between the two using the Objective-C runtime, which is resilient to the underlying ABI because it essentially overlays its own. The issue arises when you have two plugins with incompatible versions of Swift: in this case, each will load its own standard library, which will lead to conflicts since for any given function in the shared library one of the implementations has to “win out”. This will cause at least one of the plugins to be unable to interface with the standard library correctly.