Connect your AI to Arcwright.

Three steps

1. 1

   Download Arcwright and open a project

   Free on Mac, Windows and Linux. Start a new project, or open a small sample with Help › Welcome / Samples…. Arcwright has to be open while your AI works.

2. 2

   Copy your line from the Agent panel

   Open the Agent panel at the bottom of the editor. It shows the exact line for your AI app, with your own pairing token built in, and a Copy button. The connection only works on your own computer.

3. 3

   Paste it into your AI app, then ask

   Each app takes it in a slightly different place (below). Then ask for something and watch it happen in the editor. Every change is live and can be undone.

Where to paste it

Claude Code Recommended

Open the Agent panel in Arcwright and press Copy next to the Claude Code line. Paste it into Terminal once and press Return. Then start Claude Code in any folder and ask it to build something in Arcwright.

It stays connected for every project: run the line once, not every time.

Codex

Codex connects the same way, through MCP. Add Arcwright as an MCP server in Codex with the address and the authorization line the Agent panel shows, then ask Codex to build in Arcwright.

Cursor

In Cursor, add a new MCP server, choose the HTTP type, and paste the address from the Agent panel. If the panel shows an authorization line, add it as a header on that server. Then ask Cursor's agent to work in Arcwright.

Claude Desktop

In Arcwright, open Build it with AI, choose Claude Desktop and press Copy. In Claude Desktop open Settings, then Developer, then Edit Config, paste it into the config file and restart Claude Desktop. Then ask Claude to build a game in Arcwright.

Any MCP app

Arcwright speaks MCP over HTTP on your own computer. Any app that can add an HTTP MCP server can connect: use the address and the authorization line from the Agent panel.

Good first things to ask

• “Look at the scene I have open and tell me what's in it.”
• “Make it golden hour, add light rain and wind in the trees.”
• “Add a ball the player can kick, a goal, and a score on screen. Win after 3 goals. Then play it and check it works.”
• “Build a small haunted shed with a door that opens when I walk up to it.”

Your AI can press Play and control the player itself, so ask it to play the game and check its own work.

If something goes wrong

• “Pairing required” or a 401 error: The connection is missing your pairing line. Copy the line from the Agent panel again (it includes your own pairing token) and replace the old one. The token is made on your computer the first time you open Arcwright and only works there.
• The AI says it can't reach Arcwright: Arcwright has to be open while the AI works, because the AI builds inside the editor you have open. Open a project, then ask again. If you just added the server, restart the AI app.
• The player stands in a T-pose in a new game: A known issue we're still fixing: new projects can start without the default character animations. Ask your AI to use a character from one of our sample games (open Hollowreach first).
• Too many tools: Arcwright gives your AI 450+ tools. That's a lot to read, so it comes with find_tools: your AI can ask it for the right tool for a job instead of reading them all.

Still stuck? Tell us on the feedback page and say which AI app you use.

No AI app?

On the Mac, sign in and use Arcwright's built-in Claude Opus 5.5 with Sparks, or paste your own Anthropic API key. You can also build everything by hand. How the AI works inside the editor: Building with AI.