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Introducing GDKs and the Open Ecosystem



Hello SpatialOS community,

Today we are making a significant announcement that will be of interest to all of you. We are responding to your continued feedback about the issues that you have encountered in your SpatialOS projects with our upcoming Game Development Kits for both Unity and Unreal. At the same time we are also publishing the source of our current game engine integrations (SDKs). This is a prelude to open development on GitHub of the new GDKs starting this summer.

Read all the details in our blog post and share your thoughts and ideas below or on the community Discord.

Best regards,

Enabling user-created tools, workflows, and services through our API-first approach
Unreal GDK hits pre-alpha


The article above mentions “feature modules”. I envision those to being akin to plugins, or even assets as seen in the Unity asset store. How are these feature modules going to be distributed?

Is that similar to the SDKs that each will have their own repo? And how are these going to be documented.

If my above assumptions are correct it would be awesome to have video tutorials covering the usage of each individual feature module. I have always liked the way Unity does video tutorials on their website.


Hi @draconigra!

We are still researching the best way to distribute Feature Modules. Initially, for Unity at least, it’s likely that the Feature Modules will be C# assemblies in the main GDK github repo, which will also contain their documentation. In the longer run we may wish to split them out into separate repos and will certainly explore the Unity Asset Store or the Package Manager as distribution channels.

Would be interested to hear your thoughts!


Hey Callum,

For ease of installation it may be interesting at first to package a .unitypackage with the assets that need to be installed and add that to a release in Github. This should work as long as the only changes are in the Asset folder (as is the case for the Unity SDK currently).

I am currently not sure what an extra assembly would add, but the the scope of the GDKs can be anywhere from simple assets to more complicated features that I do not know about.

Just to be clear, I am not proposing to add the exported .unitypackage files onto the Asset Store. Just having them available from the github repository (or linked from the website) would help with the installation and update process.


What game development kits for Unreal can we expect first?


We have just released a follow-up post that dives deeper into the technical aspects behind the upcoming Unreal GDK. You can read it here.


Wonderful news! I’m looking forward to the release of GDK! In the forthcoming version 4.20 Unreal Engine, developers have implemented a layer for the user implementation of replication, perhaps this will speed up the integration process of SpatialOS.
Networking Updates:
Replication Driver / Replication Graph (Experimental)

  • UReplicationDriver is a base class that can be used for implementing custom server replication logic.
  • UReplicationGraph is an implementation of the UReplicationDriver that provides a replication system of optimized for games with large actor and player counts.


Another follow-up with now the first deep-dive into the Unity GDK available as well!

Additionally we have moved our development of this GDK into public territory on GitHub so you can all follow the project as the code evolves, give feedback and for the courageous soul experiment with it early on!


Glad to hear you share our excitement about the GDK!

The 4.20 changes are indeed promising and would have made our integration easier in some ways. However, GDK development started before the 4.20 preview was available. So our implementation does not use the replication driver.

We will soon evaluate how the 4.20 changes fit in with the GDK going forward. It is unlikely that our initial release will support 4.20 though.


Hello there dev-folks,

We now also have some great news for the Unreal developers amongst you. The long-expected and awaited Unreal GDK is now also available in pre-alpha on GitHub with its accompanying technical deep-dive (the second one actually for the Unreal GDK :smile: ). Do check it out and follow that repository to keep yourself up-to-date with the day-to-day developments.

More follow-up deep-dives are coming in a few weeks as well! Until then keep the feedback coming below and on Discord in the #unreal channel!