The structure of addon for Steam Workshop is the same as the classic addon system of Garry's Mod 12, except for those differences: Don't upload addons you didn't make, even fixed versions, without the author's consent. If you're going to make your addon public, please make sure it's unique and will add something new to Garry's Mod. To upload an addon to workshop you will need the following things:
Garry's Mod Publishing Utility - Java based GUI wrapper.gmpublisher (GUI for Windows, macOS and Linux).Links to such known tools: (feel free to expand) You can use alternative tools such as GUIs (graphical user interfaces) made by community members to create, extract and upload addons to Steam Workshop. Please see this page for complete set of rules:
There are a few rules before you start uploading addons. This article will teach you how to prepare and upload an addon to the Steam Workshop.
