Can asset bundles contain scripts?

My first approach was to build a .dll and use reflection to reach the functions. The problem I've run into is that I want the .dll to communicate back and forth w/ the containing page via js. For js to send a message, though, it needs to reference the game object to which the script is attached. Nothing in the .dll can be a game object, however, b/c when you use reflection to create an instance of a class in your .dll, it calls new() and game objects cannot be created using new().

What if you have scene graph 'place holder' objects that are in the application and the code you want to exec is in dll objects defined by an interface. Then the (non MonoBehaviour) implentations get somehow registered with the statically placed scene graph objects that are MonoBehaviours. The the static scene graph object would delegate the incoming call to the interface implementation (dll object) that is registered with it. You can create objects (with new, no reflection needed) from the dll. Would that work?

That's basically the approach I believe I'll have to use. From a design standpoint, though, I feel it's less than optimal b/c whenever the dll needs information from the page, via js, it has to call out to the MonoBehaviour wrapper which makes the js call, then returns the results to the dll which does some processing and then sends the results back to the wrapper which forwards it along to the game. So, there is some bouncing back and forth between the dll and the wrapper when ideally the dll should just communicate directly w/ the page.

Maybe I've got the wrong end of the stick here but I really don't understand this answer. In my project I have lots of asset bundles with scripts attached which download & run perfectly well. I can also access their script vars no problem. To do this I am just saving my asset bundles online (or locally) and downloading them from there. Simple.

@grimmy, put simply (and from what I understand), all scripts are compiled into one file that is saved with the executable distribution.

The question asks if brand new scripts can be compiled and saved with AssetBundles, to which the answer is no (with the exception of using reflection which is complicated).

When you attach scripts to game objects that are packaged in AssetBundles (the game objects in bundles, not scripts), only a reference to the script is saved in the AssetBundles, not the scripts themselves.