s&box

Built on Valve's Source 2 and the latest .NET technology, s&box is a game engine with a modern editor for creating games. This repository carries the engine source itself, meant for people who want to contribute to its development rather than simply build games on top of it.

Two routes lead to a working install. The editor can be downloaded and installed directly from Steam, or the engine can be compiled locally, since the repository includes every file the build needs.

Compiling from source has a short list of prerequisites and one entry point.

• Git: clones the repository and keeps a local copy current with upstream work.
• Visual Studio 2026: supplies the toolchain the engine builds against.
• .NET 10 SDK: provides the compiler and runtime the managed side of the engine targets.
• Bootstrap.bat: downloads dependencies and builds the engine in one step, leaving the game and editor runnable from the game folder.
• Documentation: full tutorials and API references are published on the project site for both routes.

The engine source is licensed under MIT, though certain native binaries in the game binaries folder are covered by the s&box EULA instead, and bundled third party components keep their original licenses. Anyone whose goal is making games rather than working on the engine is pointed at the getting started guide first, with bugs and feature requests handled through the issue tracker.