Build with Claude or ChatGPT
Connect an AI assistant to REM Nebula and build together. Describe the world you want - "a misty forest with a hidden temple and three coins to find" - and watch it appear in the game. Your assistant can look at what it built, fix it, play-test it and make brand-new objects with AI.
What your assistant can do
Build worlds
Open or start 3D, 2.5D and 2D worlds; place, move, resize and remove objects and building blocks; set the sky, lighting, music, terrain and game rules; undo and redo; save.
See the game
Take screenshots - from the player's view, from above, or from any camera position - so it can check its work and show you.
Make AI objects
Describe an object and it's made with REM Nebula's AI creation - first a picture, then a 3D model it can place. It uses your free daily allowance first; REM Nebula asks you in the game before any credits are spent.
Play-test
Start your world as a game, walk, jump and run to places, and report what happened - coins collected, hazards hit, whether the finish line can be reached.
While an assistant is working, REM Nebula shows a banner saying what it's doing, with a Stop AI button. You can keep using the game, and switch AI control off at any time.
First, in REM Nebula
Open Settings
Click Settings on the home screen, or press F10 anywhere in the game.
Switch AI on
Under AI assistants, turn on Let Claude, ChatGPT and other AI assistants build in REM Nebula.
Online? One more
For Claude on the web or ChatGPT, also sign in with Google in REM Nebula and turn on Also online. Claude Desktop doesn't need this.
REM Nebula has to be open on your PC while your assistant works - it's the game itself that does the building. You need the latest test build from the download page.
Claude Desktop (Windows)
REM Nebula for Claude Desktop
A Claude Desktop extension that lets Claude build in REM Nebula on your PC. Free.
- Version: 1.0.0 (2026-10-03)
- File: REMNebula-Claude.mcpb, 244 KB
- Needs: Windows, Claude Desktop, and REM Nebula open with AI assistants switched on
Install it
- Install Claude Desktop if you don't have it.
- Double-click the downloaded .mcpb file and click Install. (Or in Claude Desktop: Settings → Extensions → Advanced settings → Install Extension… and choose the file.)
- Open REM Nebula with AI assistants switched on, then ask Claude: "Build me a small island with a lighthouse in REM Nebula."
This works on your own PC: Claude Desktop talks to REM Nebula directly, with no sign-in and nothing sent to our servers.
Claude on the web, phone or desktop (connector)
Add REM Nebula as a custom connector in Claude. Available on Claude's Free, Pro, Max, Team and Enterprise plans (Free plans can have one custom connector; on Team and Enterprise an owner adds it first).
- In REM Nebula: sign in with Google and turn on Settings → AI assistants → Also online.
- In Claude: go to Customize → Connectors, click + Add → Add custom connector.
- Name: REM Nebula. Server URL:
https://api.remnebula.com/mcp→ Continue, and keep the settings Claude detects. - Sign in with the same Google account you use in REM Nebula, then click Allow.
- In a chat, turn on REM Nebula under + → Connectors and start building.
ChatGPT
ChatGPT connects through developer mode on chatgpt.com. Which plans get it - and whether ChatGPT may use tools that change things - is up to OpenAI and changes over time; at the moment full access is for ChatGPT Business, Enterprise and Edu, and on other plans ChatGPT may only be able to look (status and screenshots), not build. See OpenAI's guide.
- In REM Nebula: sign in with Google and turn on Settings → AI assistants → Also online.
- In ChatGPT: Settings → Security and login → turn on Developer mode (on Business/Enterprise, your workspace admin may need to allow it).
- Create a new app (in Plugins or Apps, depending on your ChatGPT): name REM Nebula, MCP server URL
https://api.remnebula.com/mcp, authentication OAuth. - Sign in with the same Google account you use in REM Nebula, then click Allow.
- In a chat, choose REM Nebula from the tools menu and start building.
Safety and privacy
You stay in control
AI control is off until you switch it on, and online control needs its own switch. You see everything the assistant does, can press Stop AI at any time, and REM Nebula asks you before an AI object costs credits. Disconnect any time by switching it off in Settings or removing the connector in Claude or ChatGPT.
Locked to you
On your PC, REM Nebula only accepts connections from programs on the same computer that hold a secret key it creates. Online, an AI app can only reach your game after you sign in with Google and approve it, and only while your game is open with Also online on.
What goes through our server
Only when you use online control: the assistant's requests to your game and the game's answers (including screenshots) pass through https://remnebula.com's server and are deleted as soon as they're delivered (within an hour at most). We keep which AI app you approved, so it stays connected. See the Privacy Policy.
Your chats
Your conversations with Claude or ChatGPT - including screenshots the assistant takes - are handled by Anthropic or OpenAI under their own terms and privacy policies, not ours.
Questions
The assistant says "REM Nebula isn't running" or "isn't connected"
Open REM Nebula, check that Settings → AI assistants is switched on (and, for Claude on the web or ChatGPT, that you're signed in with Google and Also online is on). The Settings window shows whether it's connected. Then ask the assistant to try again.
Does it cost anything?
Connecting and building are free. Making AI objects uses your free daily allowance (10 pictures and 2 3D models a day), and after that credits - but REM Nebula always asks you first. Your Claude or ChatGPT plan is separate.
Can I use it with other AI apps?
REM Nebula speaks the open Model Context Protocol (MCP), so other AI apps that support MCP servers over HTTPS with OAuth sign-in can connect to https://api.remnebula.com/mcp the same way.
Something went wrong
Email support@remnebula.com with what you asked the assistant and what happened. This is a test build, so feedback really helps.