s&box is a modern game engine that combines Valve’s Source 2 rendering pipeline with the latest .NET technology. It provides everything you need to build multiplayer games: a component-based scene system, real-time C# hot-reloading, integrated networking, a visual scripting editor, and a rich suite of built-in components — all accessible from a polished game editor.Documentation Index
Fetch the complete documentation index at: https://mintlify.com/facepunch/sbox-public/llms.txt
Use this file to discover all available pages before exploring further.
Installation
Get s&box via Steam or build the engine from source in minutes.
Your first project
Create a new project, add your first component, and run your game.
Scene & GameObjects
Understand the core building blocks of every s&box game.
Components
Learn how to write C# components that power your GameObjects.
Explore by topic
Scripting
Write C# components, use lifecycle callbacks, and work with the editor.
Networking
Build multiplayer games with synced properties and RPCs.
Physics & Gameplay
Rigid bodies, raycasting, character controllers, and more.
Rendering & UI
Graphics, shaders, post-processing, and the HTML/Razor UI system.
Action Graphs
Visual, no-code scripting built directly into the s&box editor.
API Reference
Full reference for GameObject, Component, Input, Networking, and more.
Get up and running
Install s&box
Download s&box from Steam or clone and build from source. See Installation.
Create a project
Open the s&box editor and create a new project. Follow the First Project guide to scaffold your game.
Write your first component
Add a C# script, extend
Component, and override OnUpdate(). Changes hot-reload instantly — no restart needed.Go multiplayer
Add
[Sync] to a property and call Rpc.Broadcast() on a method to synchronize state across clients. See the Networking guide.s&box games are written in C# and run on .NET 10. The editor is available on Windows via Steam. Building from source requires Visual Studio 2022+ and the .NET 10 SDK.