Build Roblox Games with Your Coding Agent

Before you start#

You need three things: a PromptBlox account, a coding agent and Node.js.

1. A PromptBlox account

Sign up or sign in at promptblox.ai. Use the same account when you approve the connection.

2. A coding agent

A coding agent is an AI assistant that can run commands on your computer. PromptBlox works with these:

• Claude Code
• Codex
• Cursor
• VS Code, with its built-in agent
• Windsurf
• Gemini CLI
• Claude Desktop
• Antigravity

If you don't have one yet, install one first and make sure you can chat with it.

3. Node.js 20.3 or newer

Node.js is free software that runs the PromptBlox installer. Check whether you already have it:

1. Open a terminal (see below), type node -v and press Enter.
2. If you see a version such as v24.22.1, or anything from v20.3 up, you're ready.
3. If you see "command not found" or an older version, download the LTS version from nodejs.org and run its installer with the default options.
4. Close and reopen your terminal, then type node -v again to check.

How to open a terminal

• Mac: press Command + Space, type Terminal and press Enter. See Apple's Terminal guide.
• Windows: press the Windows key, type PowerShell and press Enter. See Microsoft's Terminal guide.

Let your agent set it up#

The easiest way to connect: copy this message and paste it into your coding agent. It checks Node.js, runs the installer, shows you the code to approve and tells you when everything is ready.

Please connect PromptBlox to this computer so you can build Roblox games for me. Follow these steps exactly:

1. Run `node -v`. If Node.js is missing or older than v20.3, stop and tell me to install the LTS version from https://nodejs.org/en/download, then wait for me. Do not install it yourself without asking me first.

2. Run `npx -y promptblox-mcp`. It waits up to 10 minutes for me to approve the connection, so give the command a timeout of at least 11 minutes or run it in the background and keep reading its output. Do not stop it early.

3. When it prints an 8-character code (like ABCD-EFGH), show me the code and this link: https://promptblox.ai/connect. Tell me to sign in, type the code and press "Authorize agent". Do not open the page, type the code or approve it for me. Never ask for my password.

4. Wait until the installer prints "Connected". Then tell me which coding agents it set up.

5. If the code expires or something fails, explain the error in plain words and run `npx -y promptblox-mcp` again for a fresh code. On Windows, if PowerShell says running scripts is disabled, use `npx.cmd -y promptblox-mcp` instead.

6. When it's done, tell me to fully restart you so you can load the PromptBlox tools. After that, I'll ask you to list my PromptBlox projects to test it.

Prefer to do it yourself? Follow the next section instead.

Set it up yourself#

Step 1: Run the installer

In your terminal, run:

npx promptblox-mcp

If it asks Ok to proceed? (y), type y and press Enter.

Step 2: Approve the connection

The installer shows an 8-character code, like ABCD-EFGH, and opens the Connect page in your browser.

1. Sign in with the same account you use on PromptBlox.
2. Type the code from your terminal and press Continue.
3. Check that the request was made a moment ago, then press Authorize agent.

The code works for 10 minutes. Only approve a code from your own terminal. Never approve a code someone sends you.

Step 3: Wait for "Connected"

Back in your terminal, the installer adds PromptBlox to every coding agent it finds on your computer, then prints Connected.

Step 4: Restart your agent

Fully close your coding agent and open it again, so it loads PromptBlox.

Try it#

Ask your agent in your own words. For example:

• "List my PromptBlox projects."
• "Make me an obby on floating islands with three checkpoints in PromptBlox."
• "In my pizza game, make the oven bigger and add a tip jar."
• "Download my latest PromptBlox game so I can open it in Roblox Studio."

A downloaded game is a Roblox place file. Follow Install and open Roblox Studio to playtest it.

Good to know#

• Usage: your agent does the AI work with its own account. PromptBlox still uses some of your usage allowance for the parts it runs, such as the concept image for a new game.
• Cloud saves: new games your agent makes count toward your plan's cloud saves, the same as games you make on the site.
• More than one agent: one connection covers every coding agent on your computer. If you install another agent later, run npx promptblox-mcp again and it gets added without a new code.
• Connections last 90 days. Run npx promptblox-mcp again to reconnect.
• Safety: we email you whenever a coding agent is connected to your account.

Disconnect#

Go to the Connect page and press Revoke next to the connection. It stops working right away.

To also remove PromptBlox from your agents' settings, run:

npx promptblox-mcp remove

Troubleshooting#

• "command not found" for node or npx: install Node.js from nodejs.org, then close and reopen your terminal.
• Windows says running scripts is disabled: run npx.cmd promptblox-mcp instead.
• "Code expired or not found": run npx promptblox-mcp again to get a fresh code.
• Your agent doesn't see PromptBlox: fully quit and reopen the agent. Run npx promptblox-mcp status to check the connection.
• No browser on that computer: run npx promptblox-mcp --no-browser and open the link it prints on any device.

Official reference#

Advanced options and every installer command are in the promptblox-mcp reference on npm. Download Node.js from the official Node.js site. This walkthrough is written by PromptBlox.