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s&box modding tools

s&box modding tools is a fork of the S&box game engine to add modding tools for users such as mod management, patching core functionality through MonoMod.RuntimeDetour and more.

Planned features:

• Loading WASM (with Wasmtime) allowing mods to be written in (almost) any language along side normal .NET assemblies
• Hot reloading through the built in editor API (and custom functionality for Web Assembly).
• Custom asset loading
• Custom mod-managed mouting points for assets from other games to be used. (I.E. other source engine games)

Note that any of these features may be dropped due to viability and/or difficulty for my skillset. Feel free to contribute your own changes, additions, and enhancements!

s&box

s&box is a modern game engine, built on Valve's Source 2 and the latest .NET technology, it provides a modern intuitive editor for creating games.

If your goal is to create games using s&box, please start with the getting started guide. This repository is for building the engine from source for those who want to contribute to the development of the engine.

Getting the Engine

Steam

You can download and install the s&box editor directly from Steam.

Compiling from Source

If you want to build from source, this repository includes all the necessary files to compile the engine yourself.

Prerequisites

• Git
• Visual Studio 2026
• .NET 10 SDK

Building

# Clone the repo
git clone https://github.com/Facepunch/sbox-public.git

Once you've cloned the repo simply run Bootstrap.bat which will download dependencies and build the engine.

The game and editor can be run from the binaries in the game folder.

Contributing

If you would like to contribute to the engine, please see the contributing guide.

If you want to report bugs or request new features, see sbox-issues.

Documentation

Full documentation, tutorials, and API references are available at sbox.game/dev/.

License

The s&box engine source code is licensed under the MIT License.

Certain native binaries in game/bin are not covered by the MIT license. These binaries are distributed under the s&box EULA. You must agree to the terms of the EULA to use them.

This project includes third-party components that are separately licensed. Those components are not covered by the MIT license above and remain subject to their original licenses as indicated in game/thirdpartylegalnotices.