Setting up a Workshop collection on a server simplifies the management (install & update) of addons, items, and other additionals contents to your Garry's Mod server. 

To add these files to the Fast Download to allow your players to retrieve them during the connection on your GMod server, you must add a configuration file to explicitly tell to the server to send these files to the clients when they connect.

File creation

Use FTP access from your server to create an Lua file in the srcrds/garrysmod/lua/autorun/server folder.

This file can have any name, for practical reasons, name it for example download.lua.

Edit download.lua

This file must contain one line per Workshop item that you add to the quick download.

Example:

resource.AddWorkshop( "X" )
resource.AddWorkshop( "Y" )
resource.AddWorkshop( "Z" )
  • X = Workshop ID of the 1st Item of your collection
  • Y = Workshop ID of the 2nd Item of your collection
  • Z = Workshop ID of the 3rd item of your collection

Warning: do not put a collection ID at this level, you must put one of the items in the collection, without exception.

Restart GMod Server

Once the configuration is done, do not forget to restart the server to apply the configuration!