Roblox MCP Servers
How to make a Roblox game with Codex
Connect Codex to PromptBlox, ask for a game, then test it in Roblox Studio.
Yes, Codex can make a Roblox game, once it is connected through an MCP server. On its own it can write Luau scripts as files, but a Roblox game lives in a place file that it cannot see or build. Connected to PromptBlox, it gets a whole game built, checked and saved from your description. Connected to Roblox Studio, it can test that game in play mode.
Codex is a coding agent that runs in your terminal. MCP stands for Model Context Protocol, an open standard for connecting AI tools to other apps. The steps on this page were checked on November 11, 2026.
What you need
- Codex, installed and working. Follow its install page and make sure you can chat with it first.
- A PromptBlox account. You can connect a coding agent on any plan.
- Node.js 20.3 or newer, which runs the installer.
- Roblox Studio on a Windows or Mac computer, for testing. See how to install it.
Connect Codex to PromptBlox
Run the installer
In a terminal, run npx -y promptblox-mcp --agent codex. That connects only Codex. Leave off --agent codex to connect every coding agent the installer finds on your computer.
Approve the code
The installer shows an 8-character code and opens the PromptBlox Connect page. Sign in, type the code and authorize it. The code works for 10 minutes. Only approve a code from your own terminal, never one somebody sends you.
Wait for Connected
The installer adds PromptBlox to ~/.codex/config.toml and prints Connected. If that file already exists, it saves a backup copy before changing it. Codex asks before it runs a tool, and a build calls a few PromptBlox tools many times to submit work and check progress. The installer never changes your approval settings. The promptblox-mcp reference on npm shows how to approve those tools ahead of time. If your settings file uses multi-line text values, the installer leaves it alone and prints the lines to add by hand.
Restart and check
Fully close Codex and open it again. To confirm the connection, run codex mcp list in a terminal, or type /mcp inside Codex. PromptBlox should be in the list.
A connection lasts 90 days, and PromptBlox emails you whenever a coding agent is connected to your account. The full setup guide covers Windows, computers without a browser and common errors.
Ask Codex for a game
Ask in your own words. For example:
- “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.”
- “List my PromptBlox projects.”
Codex writes the plan for the world and the gameplay, then the scripts. PromptBlox turns the plan into Roblox parts, checks that every scripted object is connected to a real script, saves the game to your library and sends back pictures of the result. Codex can look at those and ask for fixes before it tells you the game is ready.
Codex 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, and new games count toward your plan’s saved games.
Test the game in Roblox Studio
- Ask Codex to download the game. You get a Roblox place file.
- Open the file in Roblox Studio.
- In Studio, open Assistant, choose Manage MCP Servers and turn on Enable Studio as MCP server. As of November 2026 the quick connect list in that panel includes Codex CLI. Roblox’s Studio MCP server guide has the details.
- Restart Codex, then ask it to playtest the game. PromptBlox gives it a playtest plan, it runs the plan with Studio’s own tools and reports what passed.
- Ask for fixes as changes to the PromptBlox project, so they are saved as a new version.
Roblox says connected tools can read and modify content in your open places, so save before large changes. Our page on Roblox MCP servers compares the two connections side by side.
Why not use Codex on its own?
The AI is the same either way. What changes is the system around it. Working alone, Codex writes scripts and has to place the world part by part. Through PromptBlox, a compiler builds the world from its plan, checks run before a build can finish, and every version is saved to a project you can also open on the website. Our comparison of AI Roblox game makers explains why that matters more as a game gets bigger.
Disconnect
Run npx promptblox-mcp remove --agent codex to take PromptBlox out of Codex’s settings. To end the connection itself, revoke it on the PromptBlox Connect page. The setup guide shows where.
Using a different coding agent?
Questions about Codex and Roblox
Can Codex make a Roblox game?
Yes, once it is connected through an MCP server. On its own, Codex can write Luau scripts as files, but it cannot see or build a Roblox place. Connected to PromptBlox, it gets a whole game built, checked and saved from your description. Connected to Roblox Studio, it can work in your open place and test in play mode.
How old do I have to be to use Codex?
Codex’s terms require users to be 13 or older, with a parent’s or guardian’s permission under 18. PromptBlox is for creators 13 and older. If you are under 18, read the terms with a parent or guardian before you sign up.
Do I pay for both Codex and PromptBlox?
Codex has its own plans, set by its maker, and it does the AI work with its own account. PromptBlox uses some of your weekly usage allowance for the parts it runs, such as the concept image for a new game. You can connect a coding agent on any PromptBlox plan.
Does Codex work with Roblox Studio directly?
Yes. Roblox Studio has a built-in MCP server, and as of November 2026 its quick connect list includes Codex CLI. That connection works on the place you have open. PromptBlox is the part that builds a new game and saves it as a project.
How do I check that PromptBlox is connected?
Fully close Codex and open it again, then run codex mcp list in a terminal, or type /mcp inside Codex. PromptBlox should be in the list. You can also run npx promptblox-mcp status in a terminal.
No coding agent? Describe your game on the website instead.
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