How to share assets (Prefabs/Materials) across multiple projects?

We are looking for a way to share assets between multiple projects. We have multiple asset databases (consisting of prefabs and materials) which we are permanently working on. These asset databases are needed in several different unity projects.

Currently we share these databases via “.unitypackage”, but the big problem is that the assets are not up-to-date automatically. The process of updating all databases in the various projects is very time consuming and error prone.

We are looking for a solution to implement one or multiple of these asset databases with just 1 click and a way to keep the asset databases up-to-date easily in all projects. Preferably, the assets are “read only” and can only be edited in the main database project, so no one is overwriting/damaging the database assets accidently.

The most interesting thing we have found are “symbolic links”, they do quite what we want. Unfortunately the database gets corrupted, when more than 1 open project is referencing them, so we cannot use them.

We are experimenting with multiple git-repositories (one per database), but this workflow is hard to manage for people that are not experienced with git or vcs in general. Maybe collaborate has integrated such a solution by now?

The new package manager still seems to be an option, we did not have a deeper look yet.

Since there are many large teams out there, is there any “best practice” how this should be handled?