How to install addons on your Garry's Mod server

There are two ways to add content to a Garry's Mod server. A workshop collection is the tidy option, because players download the same content automatically. Uploading addons by hand still works for anything not on the workshop.

1. Build a workshop collection

1. On the Steam Workshop for Garry's Mod, create a collection and add the addons you want.
2. Set the collection to public.
3. The number at the end of the collection address is its ID.

2. Point the server at it

1. Stop the server in the Game Panel.
2. Open the Startup page for your server. It is not linked in the sidebar, so add /startup to the end of your server's panel address.
3. Set the workshop collection ID field to your collection.
4. A Steam Web API key is also needed for the server to download the collection. Create one on your own Steam account and set it in the matching field.
5. Start the server and watch the Console as it downloads each item. The first start after a large collection takes a long time.

3. Upload an addon by hand

1. Stop the server.
2. In the Files tab, upload the addon folder into garrysmod/addons.
3. The folder must contain the addon's own lua, models or materials folders directly. A wrapper folder is the usual reason an addon does nothing.
4. Start the server and check the console.

4. Getting content to your players

• Workshop collection items are downloaded by the client on join.
• Hand uploaded content needs a fast download setup or players will see missing textures and errors.
• Ask your players to subscribe to the collection in advance if the first join is slow.

5. When an addon breaks the server

• Add addons a few at a time and restart in between.
• Lua errors in the console name the addon and the file.
• Remove the last thing you added and restart to confirm which one is at fault.
• Take a backup before adding a gamemode or anything that writes to a database.

Open a ticket from Support in the Client Area with the console output if an addon will not load.