Steam Workshop Collections are used to add addons/mods to your server running a Source game such as Team Fortress 2, Garry's Mod, CS:GO, etc.
To add a collection to your server, you must have the workshop collection ID. You can either create your own collection or use an existing one containing addons you'd like to use. If you'd like to create your own collection, please see this article. If you already have a desired collection you are ready to proceed to step 1.
You may browse workshop collections for your desired game from your Steam client or Steam's website. This guide will use the Steam client.
Select Community then Workshop to enter the workshop area.
In the search bar, enter the name of the game that you'll be creating a collection for. Garry's Mod is the most commonly modified source game, so we will use it for this example.
Once you have selected your desired game, choose Browse, and then Collections. You may then browse for a collection you'd like to use.
Here is an example of a workshop collection's URL (this link is purely an example and does not navigate anywhere):
Your workshop collection ID is the value for ID. In this case, the collection ID is 123456789.
1. After you have located your collection ID, on the control panel click FTP File Access and then edit the server.properties file.
2. Paste your workshop collection ID after the setting host_workshop_collection=.
3. Afterward, click Save Changes and restart your server. Your workshop collection will automatically be applied on restart.
If you experience any issues adding a workshop collection, contact our support team for help!