KroysEngine

Your game

Build the game on this side.

A Vulkan engine with a focused editor, C# scripting and one codebase for single-player and dedicated servers.

Extend the editor

Your tools, written in C#

Add panels, commands, importers and asset types as small C# plugins. Save the file and the running editor rebuilds and reloads it in seconds.

panels and menusyes

undoable scene editsyes

crash isolationper plugin

native pluginsC and C++

Client

Predict on this side

Players move the moment they press a key. The client predicts its own movement and quietly reconciles with what the server decided.

predictionon

remote interpolationon

lag-compensated hitson

Authoring

Every tool is one window

Animator, VFX Studio and the UI editor share one layout: library on the left, canvas in the middle, inspector on the right, and the result running live inside the tool.

MCP

Work with your AI assistant

KroysEngine speaks the Model Context Protocol (MCP). Turn on the MCP plugin, connect an AI assistant to the running editor, and it looks through your scenes, adds and edits entities and materials, builds scripts and reads the errors. Connect over MCP

every changeone undo step

file writesyou confirm

connectionthis machine only

headless projectsstdio

Migrate

Bring your game over SOON

Import scenes, prefabs, materials and animations from an existing project. A conversion report lists what moved over exactly, what was approximated and what needs your attention.

Learn

Start on this side

Getting started FROM SOURCE Editor manual F1 IN THE EDITOR C# scripting reference API Plugin SDK C# · C++

Your tools

Rewrite the editor on the other.

Open the editor up and change it while it runs, then run the same engine on your server.

Read the docs

LevelTools.cs

public sealed class LevelTools : EditorPlugin
{
    public override void OnLoad() =>
        Host.AddPanel(new("Main", "Level Tools"), ui =>
        {
            if (ui.Button("Bake lighting"))
                Host.RunTask("Bake", BakeAll);
        });

    private static void BakeAll(TaskProgress progress) => progress.Report(1.0f, "Baked");
}

saved · rebuilt · reloaded in the running editor

Server

Decide on the other

The dedicated server runs the same physics, animation and navigation as the game, so both sides agree. Game modes and bots are C# on the server.

public sealed class Arena : GameMode
{
    protected override void OnPlayerJoined(Player player)
    {
        while (GameSession.PlayerCount < 4)
            GameSession.AddBot();   // bots walk the navmesh
    }
}

VFX Studio

VFX Studio · capture coming with the showcase scenes

Wire emitters and parameters in the graph and watch the effect burn in the same window.

Assistant · connected over MCP

Add a ring of eight torches around the campfire and make them flicker.

scene_search "Campfire" → 1 entity

prefab_instantiate Prefabs/Torch × 8, radius 4 m → 8 entities

component_add VfxEffectComponent × 8 → 8 components

Done. Eight torches stand in a ring around the campfire, each with the flicker effect. Every change is undoable in the editor.

Conversion report

Scenes and hierarchyexact

Meshes and texturesexact

Materialsapproximated

Animator state machinesapproximated

Gameplay scriptsport with AI help

An AI assistant connected to the editor will help port the code that cannot be converted automatically.

Source

Or jump to the other

One repository with the editor, the player, the dedicated server, C# scripting and the plugin SDK. Free under the MIT license.

Build from source What's new