Setting up a Steam Workshop collection for your GMod server

A Steam Workshop collection is the best way to manage addons for your Garry's Mod server. Players automatically download all required content when they connect, and you manage the entire list in one place. In this article you learn how to create a collection, link it to your server and optimize it for the best experience.

Why use a Workshop collection?

Without a collection, players have to manually download every addon, which leads to missing textures (the infamous pink-and-black pattern), missing models and console errors. With a collection everything is downloaded automatically upon connecting.

Advantages of a collection:

• Players automatically get all required content
• Updates are distributed automatically
• You manage everything from a single Steam overview
• Easy to add or remove addons

Creating a collection on Steam

1. Go to the Garry's Mod Workshop on Steam.
2. Click "Create Collection" in the top right corner.
3. Give the collection a name (for example the name of your server).
4. Add a description and set the visibility to "Public".
5. Search for the addons you want to use and add them one by one to the collection.
6. Publish the collection and note the collection ID (the number in the URL).

Linking the collection to your server

To link the collection you need a Steam Web API key:

1. Request an API key at steamcommunity.com/dev/apikey.
2. Add the following parameters to your server's startup command line:

-authkey "YOUR_API_KEY" +host_workshop_collection "COLLECTION_ID"

On startup the server downloads all addons from the collection. Players who connect then automatically download the same addons.

Adding addons to the collection

Want to add a new addon:

1. Find the addon in the Steam Workshop.
2. Open your collection and click "Add Items".
3. Search for the addon and add it.
4. Restart your server so the new addon is downloaded.

Players receive the new addon automatically on their next connection.

Commonly used addons per game mode

Performance optimization

Too many addons slow down your server and increase download times for new players. Keep these guidelines in mind:

• Total size: keep the total download size under 2 GB. Larger collections cause new players to wait for minutes.
• Number of addons: 30 to 50 addons is a healthy maximum for most servers. More than 100 addons can cause instability.
• Duplicate content: check whether multiple addons contain the same models or textures. Overlapping content wastes memory.
• Abandoned addons: remove addons that are no longer maintained by the author. Outdated addons can cause crashes after a GMod update.

Troubleshooting

Players see pink-and-black textures

This means an addon or the base game uses CSS (Counter-Strike: Source) textures that the player does not have. Add a CSS content pack addon to your collection, or instruct players to install CSS.

Addons do not load

Check the server console for error messages. Common causes:

• Incorrect API key: generate a new one on the Steam website.
• Collection set to private: change the visibility to public.
• Addon removed from the Workshop: replace it with an alternative.

Download time is too long for new players

Enable FastDL or a Workshop download server to increase speed. Additionally, remove large addons you are not actively using. Large map packs and HD texture packs are the most common culprits.

Do I also need to place addons manually on the server?

No, if you have correctly linked the Workshop collection, the server downloads all addons automatically on startup. You do not need to copy anything manually. If you still want to use manual addons (that are not on the Workshop), place them in the garrysmod/addons/ folder. Manual addons and Workshop addons work alongside each other.