The game engine for Three.js.

Built on Three.js, on its modern path

Gessa uses Three.js's WebGPU renderer with WebGL2 fallback on compatible browsers. The editor connects that rendering foundation to game state, physics, visual scripting and multiplayer. Use glTF/GLB models in your asset workflow and keep shaping the game in the same browser platform.

From an idea to a shared game

Build your game's rules and world with AI. Generate models, textures, images and audio, work with friends through live co-editing, and test the experience with server-authoritative multiplayer. Cloud saves and versions keep the project connected as you develop it. Gessa's built-in AI is free.

For the agents making Three.js games right now

If your Claude Code or Codex session is mid-way through a raw Three.js game, Gessa still serves it: the engine exposes MCP tools for game authoring and assets, including the generation pipeline, so an agent can produce a game-ready .glb model, texture, or image file for its own project. The agent quickstart describes client connection options, and the asset library is browsable with a per-asset license on every item.

Explore the workflow

Start with the multiplayer guide to turn an idea into rules you can test with a friend. Explore the asset library for models and textures, or compare workflows with Rosebud and Seele. Gessa brings its engine, AI assets, collaboration and multiplayer together in your browser.

Questions

What is a Three.js game engine?

Three.js is a 3D rendering library. A game engine brings rendering together with systems such as game state, physics, input and multiplayer. Gessa combines these systems with a browser editor and built-in AI.

Is Gessa built on Three.js?

Yes. Gessa uses Three.js's WebGPU renderer, with WebGL2 fallback on compatible browsers. Its game creation workflow includes models, textures, audio, physics and multiplayer.

How can I use Gessa with an existing Three.js project?

Use Gessa's asset library and MCP tools to bring assets into your project. For game creation inside Gessa, its editor, visual scripting and AI operate on the engine's shared game representation. Importing a model and importing an entire JavaScript application are different workflows.

What does Gessa provide for making games with AI?

Gessa brings built-in AI, asset generation, game authoring, server-authoritative multiplayer and live co-editing into one browser platform. Describe an idea, shape the assets and rules, test the game, and publish it for people to play.