Valve Source SDK
Open-source game development SDK for creating mods and games using Valve's Source 1 engine.
What is Valve Source SDK?
Source SDK 2013 is the official development kit for Valve's Source 1 game engine, providing the complete source code for Half-Life 2, Half-Life 2: Deathmatch, and Team Fortress 2. It enables developers to create custom game modifications (mods) and standalone projects by building upon these established game foundations. The SDK integrates with the Steam platform for both development and distribution of mods.
Game developers and modders who want to create custom modifications for Source 1 engine games or develop new games using Valve's established engine technology. This is particularly valuable for those targeting the Steam platform for distribution.
Provides direct access to Valve's professional game engine source code, offering a robust foundation for mod development that maintains full compatibility with the Steam ecosystem. Unlike generic game engines, it comes with complete implementations of popular Valve titles ready for modification.
Overview
The 2013 edition of the Source SDK
Use Cases
Best For
- Creating custom game modifications for Half-Life 2 or Team Fortress 2
- Developing standalone games using the Source 1 engine technology
- Learning game engine architecture through professional-grade source code
- Building multiplayer mods that integrate with Steam's networking infrastructure
- Porting existing Source engine mods to the 2013 SDK version
- Creating game content for distribution on the Steam platform
Not Ideal For
- Commercial game development requiring proprietary licensing and revenue generation
- Projects targeting modern graphics features or platforms beyond Windows and Linux
- Teams needing extensive official support, tutorials, or a large active community for troubleshooting
- Developers seeking a fully open-source engine with permissive licensing for any use case
Pros & Cons
Pros
Includes full source code for Half-Life 2, HL2: Deathmatch, and Team Fortress 2, providing a professional-grade foundation for mods without starting from scratch.
Automatically builds against Steam Runtime for Linux, ensuring seamless compatibility with Steam's ecosystem for both development and distribution.
Offers build scripts for Windows (Visual Studio) and Linux (Podman), supporting development on multiple operating systems with clear instructions.
Provides direct links to Valve's partner documentation for distributing mods on and off Steam, streamlining the publication process.
Cons
The SDK is licensed only for non-commercial use under the SOURCE 1 SDK LICENSE, severely limiting its utility for commercial game projects.
Based on the Source 1 engine, which lacks modern features compared to newer engines like Source 2 or Unreal Engine, and may have compatibility issues with contemporary hardware.
Requires specific tool versions (e.g., Visual Studio 2022, Python 3.13) and a Steam installation, creating a steep initial setup barrier for newcomers.
Frequently Asked Questions
Related Projects
imguiDear ImGui: Bloat-free Graphical User interface for C++ with minimal dependencies
C/C++A curated list of awesome C++ (or C) frameworks, libraries, resources, and shiny things. Inspired by awesome-... stuff.
ProtoBufProtocol Buffers - Google's data interchange format
JSON for Modern C++JSON for Modern C++
Found a gem we're missing?
Open-Awesome is built by the community, for the community. Submit a project, suggest an awesome list, or help improve the catalog on GitHub.