Create a Mod (Source)/en
The Create a Mod wizard automates the process of creating a Source mod. It:
- Creates a new mod under
steamapps\SourceMods\ - Installs a copy of the source code, with associated Visual Studio Project File
- Creates a Game Configuration for your mod in the Source SDK
Note:You will need to restart Steam for a new mod to appear in your library.Engine branch
Before starting a mod you need to choose which version of Source you will use. Change the SDK's engine version to the one you want.
Source 2006- Outdated - Original
Half-Life 2: Episode One mod. Only included for backwards compatibility reasons. 
Source 2007- Outdated - Original
Orange Box branch mod. 
Source 2009- Outdated - Updated Orange Box mod. You cannot make a mod for Source 2009; you can make a content-only mod of a 2009 game by following Creating a Mod manually.
Alien Swarm (via Alien Swarm SDK)- The oddball of the bunch. Alien Swarm is totally free to play and its SDK includes source code, but it's source code is for a top-down shooter. It also lacks many of the HL2-compatible code's peripheral tools and cannot access HL2's content.
Source 2013- In 2013, Valve phased out the Source SDK with the release of SteamPipe. With this change, they updated the source code to the latest version of the Source-1-Engine for the HL2-based engine branch. This time around, the source code is not made available via an SDK launcher, but is instead hosted on Github. See Source SDK 2013 for more information.
Note:If you wish to compile on one of the engine branches, Source 2006 is Visual Studio 2005, Source 2007 is Visual Studio 2010, Alien Swarm engine branch is Visual Studio 2010 & Source 2013 is Visual Studio 2013.)Note:At this time, 
CS:GO is the only Valve-made Source Engine title with 64-bit support, and is only 64-bit on MacOS and Linux. (By extension, this means that only mods based on CS:GO will be able to work on macOS Catalina and later, as these lack 32-bit support.)
Warning:Your Engine Version in the Source SDK must match the Engine branch of your mod! Failing to do this will result in Source SDK tools being unable to load required resources.The SDK wizard
Project type
This section only applies to Half-Life 2 Mods!
When you start the wizard, you will have to choose which project to work with.
- Half-Life 2 Single Player
- Projects for or
. If you do not own / this option will be greyed out. - Half-Life 2 Multiplayer
- Projects for Half-Life 2: Deathmatch. This option is only available if you own Half-Life 2: Deathmatch; otherwise it will be greyed out.
- Multiplayer mod from template
- A specially-created SDK project that allows you to configure settings such as if your mod is team based, or if you have abilities such as sprinting and prone. This option does not require Half-Life 2: Deathmatch.
- Source code only
- Dumps the code without creating an actual mod. This option is handy if you are just creating a server plugin.
Whichever option you choose, you get the same actual source code files (even if you didn't own one or another game). You also get an "everything" solution which includes a collection of development tools.
Mod Information
The first option on this page is where you want the source code extracted to. The second is the name you want to use, which also defines the output folder for your compiled content (does not appear if you chose source code only).
Creating a mod manually
It's surprisingly simple:
- Create a folder under
steamapps\SourceMods\(A mod can actually reside anywhere, but placing it here allows Steam to detect and launch it.) - Create a gameinfo.txt in the folder. You now have a mod!
- Open the SDK launcher and switch to the relevant engine branch.
- Choose "Edit Game Configurations" and click "Add". Enter your mod's name and folder.
To get the source code (or indeed any other files of Valve's that you want to modify) you will need to use GCFScape and access depot_211_dir.vpk in the Steam\SteamApps\common\SourceSDK\vpks folder. Remember to change the custom build steps to point to your mod's folder.
Utilities
XBLAH's Modding Tool - Creating a mod- XBLAH's Modding Tool
- Creating a bare-bones
Source mod usually requires more than just creating a gameinfo.txt. Mods based on Source games can be created with the XBLAH's Modding Tool using an intuitive interface, that creates all the required files and directories. 
Mapbase mods are also supported. See more.
