Estella

A 2D and 3D game engine whose editor is an MCP server.
Your AI agent builds the game with the same 167 tools the editor's own UI uses — then ships it to the web, mini-game platforms, playable ads, desktop and native mobile.

Website  ·  Agent  ·  Getting Started  ·  Documentation  ·  QQ群 481923584

_{Every frame is one MCP tool call into the editor, captured as it happened — no mouse involved.}

Your agent drives the editor

The Estella editor speaks the Model Context Protocol. Connect Claude Code, Cursor, Codex or any MCP client, and the agent works inside the real editor rather than around it:

• It builds — creates projects, spawns entities from the editor's own Create catalog, writes component fields, makes prefabs, paints tilemaps, writes and type-checks scripts.
• It looks — takes screenshots of the viewport and the running game, replays a frame draw by draw, compares the game with reference images, and audits what a scene's look lacks.
• It plays — enters Play mode, steps time deterministically, sends input and clicks UI by name, runs scripted playtests, then reads the running world back.
• It makes assets — images, sound effects, music and 3D models, each answered with a picture of what it made.
• It ships — reads project health, exports the game, and drives a build running on a connected phone.

Every call goes through the editor's command surface: each one is one undo step, you watch it happen in the window, and you can take the mouse back at any time. The editor starts read-only; an agent edits only after you allow it in Window → Connect AI Tools…, which also writes the client's MCP config for you.

Group	What the agent gets
core	scene tree, entities, components, play / step / input, screenshots, logs, undo
assets · prefab · authoring	asset documents and import settings, tilemaps, prefabs and variants, physics bodies, UI events
look · render	reference images beside the game, light and field sweeps, frame capture and replay, shadows, LOD, bakes
code · project	scripts, symbol search, type-check, project settings, health, export
image · sound · modeling	draw sprites and textures, compose sound and music, build 3D models from steps
play · view · device	gamepads, time scale, scripted playtests, editor view, and a game running on a connected phone

→ Connecting an agent

Why Estella, when Unity and Unreal have MCP too?

An MCP server can be bolted onto any editor. What an agent can actually get done depends on what sits behind it.

• The protocol is the editor, not a plugin on it. The 167 tools call the pipelines the editor's own menus, inspector and toolbar run, so an agent's edit is the edit a person would have made, and undoes the same way. Calls are schema-checked and permission-gated by the editor itself.
• The agent can check its own work. It steps a paused game frame by frame, so "play three seconds, then look" is the same frame every run. It sees the game, not just the log: screenshots, a frame replayed draw call by draw call, the game set beside a reference image, scripted playtests that read the running world back.
• The agent can make what the game needs. Sprites, textures, sound effects, music and 3D models come from tools inside the editor, so a prototype does not stop at grey boxes while someone opens five other programs.
• Everything is text. Scenes, prefabs and materials are JSON; gameplay is TypeScript. An agent reads and writes the project directly, and every change is a reviewable diff.
• It ships where heavier engines struggle. A WebAssembly runtime that loads on a phone browser, seven Chinese mini-game platforms, single-file playable ads for the major ad networks, and native Android / iOS apps — from one project.
• It is open. The runtime, SDK, pipeline and CLI are Apache-2.0: no royalties, no seats, no runtime fees. The editor is a free download.

Rendered in real time

_{One day on the Amazon Lumberyard Bistro, recorded frame by frame from the running game: a sun that follows the clock, weather that turns from clear to mist, rain and snow, baked bounce light, reflections and volumetric haze. Scene © Amazon Lumberyard, CC BY 4.0, modified.}

What's inside

Estella is a C++ engine with a TypeScript SDK. The core runs as WebAssembly on the web and natively on desktop and mobile; game logic is written as ECS systems in TypeScript.

2D — sprites and sprite animation, tilemaps (with LDtk import), Spine 2.1 – 4.3 and DragonBones, 2D lights and shadows, UI with layout, rich and bitmap text, particles, Box2D physics, native 2D rigs.

3D — glTF / FBX import, PBR materials, directional / point / spot lights with shadows, sky atmosphere with time of day and weather, baked lightmaps, light and reflection probes, SSR, SSGI, height fog, terrain, water, foliage, skeletal animation with spring bones, navigation, Jolt or PhysX physics, streamed large worlds.

Everywhere — one renderer for 2D and 3D on WebGL 2 and WebGPU, and one project exports to:

Target	What you get
Web	a static, self-contained build
Mini-games	WeChat, Douyin, Kuaishou, Bilibili, Alipay, Huawei and quick games
Playable ads	one inlined index.html for Meta, Google, Unity, AppLovin, Mintegral, TikTok / Pangle and MRAID networks
Desktop	a native app on Windows, macOS and Linux — no Chromium
Android / iOS	a native arm64 app on Vulkan / Metal — not a WebView

Getting Started

Install. Download the editor for Windows or macOS from estellaengine.com — always the newest release. Every build is also on the releases page.

Create a project. Open the editor, click New Project, pick a template.

Write a system.

import {
    defineComponent, defineSystem, addSystem,
    Query, Mut, Res, Time, LocalTransform
} from 'esengine';

const Speed = defineComponent('Speed', { value: 200 });

addSystem(defineSystem(
    [Res(Time), Query(Mut(LocalTransform), Speed)],
    (time, query) => {
        for (const [entity, transform, speed] of query) {
            transform.position.x += speed.value * time.delta;
        }
    }
));

Press F5 to play — or connect your agent and ask it to do all three.

Documentation

Everything lives at estellaengine.com/docs.

	Start here	What it covers
	Quick Start	install the editor, make a project, press play
	ECS	components, systems and queries — how game logic is written
	AI Agents	connect Claude Code, Cursor or Codex to the editor
	Time of Day	a sun and sky that follow the clock
	Weather	mist, rain and snow
	Exporting	web, desktop, playable ads and the rest, from one project
	Mini-game platforms	WeChat, Douyin, Kuaishou, Bilibili, Alipay, Huawei
	Android & iOS	native arm64 apps

Feedback

Estella does not accept pull requests. Bug reports and feature requests are welcome as issues — see CONTRIBUTING.md for what to include, and for building the engine from source.

Maintainers: see the release procedure for candidate builds, acceptance evidence and publishing.

License

The engine runtime, SDK, asset pipeline, CLI, project templates and editor plugin API in this repository are licensed under the Apache License, Version 2.0 — free for any purpose, commercial use included. We follow Semantic Versioning and keep a CHANGELOG.

• The visual editor is a separate, free product built on this engine; its source is not public. Everything needed to build, run and ship a game is here — see BUSINESS_MODEL.md.
• Trademarks. The license covers the code, not the "Estella" / "ESEngine" names or logos: say your project uses Estella, but don't ship a fork under that name.
• Spine. The bundled Spine Runtimes are not open source; a game that uses Estella's Spine integration needs its own Spine license. See NOTICE.