How to publish a mod to Steam Workshop

If you are uploading a mod that you wrote before the Steam Workshop, please make sure you read our IMPORTANT migration info.

If the Steam client is running and you are logged into Steam, you will see the following screen when you click on Mods in the main game menu.

The mods overview has been completely reviewed and supports thumbnail images now, as well as a special workshop symbol to indicate that a module has been installed through Steam Workshop.

Clicking on the button Steam Workshop will open up the Steam Overlay and a browser window directly into GDT’s workshop page, so that you can subscribe and/or (if you’re an author) further manage your contents.

If you want to publish a mod to Steam Workshop, you must first agree to Steam’s legal agreement (here and here), if you haven’t already done so.

Once agreed, you will be able to submit your contents to the Steam Workshop. For this, click on Publish Mod. The following screen will be displayed:

To properly publish a GDT mod to the Steam Workshop, you need to enter the title of your mod (e.g. MyAwesomeMod) and specify the folder (Mod Source Folder) where the mod that needs to be published is located (e.g. c:\ModDev\MyAwesomeMod).

Description and Image Preview are optional fields, but we recommend you use them, too.

Specifying a preview image will upload the image to Steam and automatically create a preview (thumbnail) image that is used in the mods selection panel.

The information gathered from title, description and image preview will be automatically put into the package.json of your mod.

When you’re satisfied with the information entered, click Publish to upload and publish the mod to Steam Workshop.

It’s also a good idea to go to the Workshop website and add more details and screenshots to your mod

Updating your mod

If you want to update one of your existing and published mods, you can use the Update Mod feature of GDT’s mod panel:

Your published mods are displayed in the left hand list (the list is manually updated by clicking the Update Mod button again).


Weird, I can’t click the links, they’re broken to me.

I think you have to be logged in to Steam to see these pages.

Good work GHG!
You avoided my feelings of headache when uploading something! (I upload Gmod mods)


You’ve probably changed this already, but

shouldn’t “Image Preview” and “Choose Image” be turned around?

@Pastract Thanks its already fixed now.

Hi @PatrickKlug @DanielKlug @alphabit ,

Here’s my feedback:

-When clicking on ‘steam workshop’ nothing happens.
-When I try to publish my mod. The status keeps saying ‘Publishing…’ When I close the mods panel I get this error:

Also I noticed when I select my folder, the status will stay ‘Reading package.json’

Extra info: I have accepted the workshop agreement.

Nice job on the update though!

Kind Regards,

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@PatrickKlug @DanielKlug @alphabit

I currently have the same problem as @kristof1104 that my status keeps saying “Readin package.json…” or “Publishing”

However, when I click on Steam Workshop the steam page pops up (like it’s supposed to do as I assume), so @kristof1104, maybe this has something to do with your steam settings?

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Thx @DzjengisKhan I reinstalled Steam and now the Steam Workshop button works.

Still can’t publish my mod though… :frowning:

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@kristof1104 awesome that it works now :smile:

However, I still can’t publish my mod as well :frowning:

But the weird things is, is when I select a mod folder from a mod I already installed using the workshop, all the information automatically gets filled in the fields and when I compare package.json files, nothing (but the image) is different, so I have no clue why it doesn’t work :sob:

Do you have access? Do you too @DzjengisKhan

Of course we have access, how else could we access the new mod page? :stuck_out_tongue:

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XD. Alright. Give it some time, maybe they’re fixing something.

@alphabit should be online in a bit and be able to track this down. If you want to help the process, you could PM him the files you are trying to publish or provide some more debug info here.


I can’t update too, but I already had published my mod. You see, it says that it’s uploaded, but it’s not updated, it has the old version.

Hi all :slight_smile:

Thanks to @kristof1104 valuable help, time and assistance, I managed to find out where the problem(s) reside(s) when it comes to publishing and/or updating a mod.

Starting to provide relief to the mentioned problems. Stay tuned… a new update is coming very soon :slight_smile:

Amazing! Can’t believe we’re getting a new update on an early access update about a workshop update. Updateception.


We love x-ceptioning, so we do with our updates :wink:

Hoping for an update to the api though.

Do you mean something like this?

  • Changed: Added new events for modders: GDT.eventKeys.gameplay.staffApplicantsGenerated, GDT.eventKeys.gameplay.staffHired, GDT.eventKeys.gameplay.staffFired, GDT.eventKeys.mod.allLoaded, GDT.saves.loaded, GDT.saves.newGame
  • Changed: Refactored the way researchable topics are calculated to make it more accessible to modders.
  • Changed: Exposing more internal review methods to modders.
  • Changed: Exposed more internal methods for managing staff.
  • Changed: moved grid sale calculation to Sales.applyGridSales to allow easier modding.