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Need ability to replace Improbable Launcher with our own custom C# launcher



Our existing custom C# launcher for our UE4 game performs a number of functions that we would like to retain.

What provision will be made to permit connection from a custom launcher?

SpatialOS Requests

We’ve never seen this kind of use case, but conceptually we’re not opposed to it! Does your launcher update your game from a CDN? If so, it could be rigged up to access our Asset Database in a similar fashion (although we’ve never had anybody do this before, it is theoretically possible).

It’s worth noting, with our users that distribute through Steam, the Improbable Launcher doesn’t feature at all in the flow. Steam directly starts the game engine binary.


Our launcher is still very much a work in progress and is designed to launch an Unreal client that connects to an Unreal dedicated server.

The launcher does not, however, interact with the Unreal Dedicated server at all. The client is set up to connect to the server.

While we may distribute through Steam, we will also be marketing the game independent of Steam.

At this point, I’m not really sure what functions the Improbable launcher performs.

Currently, our launcher,

1 Has custom graphics, including the stub of a news feed.
2. Registers/Logins the player
3. If new registration, creates new character and generates basic character stats on our database server (funtions planned to be moved to a separate socket server to insulate db server)
4…Updates the client
5… Retrieves PlayerID
6. .Launches the client while passing PlayId and other command line parameters

If the Improbable launcher can perform some semblance of these functions (including the custom graphics) or be adapted to these needs, we’d be happy to get started on that.

Might there be a possibility of a step by step tutorial or guide for adapting the launcher?


The current roadmap for our launcher is really around it as a very lightweight downloader for prototyping & playtesting deployments quickly through the browser rather than as a modular, extensible launcher intended for production released games like it seems you’d need. I think we could eventually get there but for now I’d suggest you’ll likely be more successful rolling something specifically for your game!

The launcher does a similar dance around passing in a token that authenticates your play session. For rolling a custom launcher, the important thing for us is how it exchanges session token for your player (steam / playfab / etc) for a SpatialOS worker connection token - we currently have a REST API that does this for our own launcher & steam integrations, but we have yet to make it fully public.

Right now it supports steam session exchange, but not anything else - would you have any interest in another session provider being used?


If I understand this correctly, currently the only way to play a game with an Improbable back end is through Steam? This is extremely limiting.

Edit to ADD: Have since had section 2.3 of the Improbable EULA brought to my attention. “Unless otherwise agreed between the parties in writing,” We would like to investigate this possibility.

We don’t particularly want to be confined to any session provider and would in fact prefer the ability to create our own authentication server.

If that is not feasible at this time, we will begin the process of integrating the Steam API into our launcher. At some point, of course, we will need further information from Improbable on this issue.
“Modular, extensible launcher intended for production released games” is exactly what we are aiming for. Our game is a commercial endeavor by our small company and will be in time a published, commercial game targeted at a niche market.

While we understand that, given that its first and (still, apparently) main focus is Unity, SpatialOS has been directed toward the legions of casual developers that exist, its potential to easily enable small population, truly indie MMORPGs is what has attracted us to it.

We only learned of Spatial after CoE’s announcement and it seemed tailor made for our needs. We had, perhaps unwisely, taken it for granted that Spatial would be suitable for commercial projects of the sort that we are working on.