How to connect Claude Code, Codex and Cursor to Roblox Studio

How do I turn on Roblox Studio's MCP server?

These steps are the ones on Roblox's Creator Hub page Connect to the Roblox Studio MCP server, last updated 3 November 2026, and on the README of Roblox/roblox-studio-agent-plugin. A toggle or file path those pages do not publish is not added here.

The server is built into Roblox Studio. It speaks MCP over stdio on your computer. A connected client can read the open place, edit scripts, run Luau and drive play mode. Roblox's docs say the client can read and modify that place, so only connect a client you trust.

Turn the server on

1. Install the latest Roblox Studio and the client you want to use.
2. Open Assistant.
3. Click …, then Manage MCP Servers.
4. Turn on Enable Studio as MCP server.

When a client connects, that panel shows a green indicator and a count of connected clients. The plugin README words the same switch as …, then Settings, then MCP Servers, and notes Manage MCP Servers as the older label.

Quick connect

Roblox's quick connect list is Antigravity, Codex CLI, Claude Code, Claude Desktop, Cursor, Gemini CLI and Visual Studio Code. The steps are the same for each name on that list.

1. Go to Assistant Settings, then MCP Servers.
2. Expand the Quick connect dropdown. It lists supported clients that are installed on that computer.
3. Turn on the client you want.
4. If the client is not in the list, install it and restart Roblox Studio.

JSON configuration

If quick connect does not cover the client, Roblox publishes this stdio configuration for clients that use an mcp.json file. Add the Roblox_Studio entry to the mcpServers object you already have. A missing comma between entries makes the file invalid. The Creator Hub page does not name Cursor's or Claude Desktop's config-file path, so this guide does not invent one.

{
  "mcpServers": {
    "Roblox_Studio": {
      "command": "cmd.exe",
      "args": [
        "/c",
        "%LOCALAPPDATA%\\Roblox\\mcp.bat"
      ]
    }
  }
}

{
  "mcpServers": {
    "Roblox_Studio": {
      "command": "/Applications/RobloxStudio.app/Contents/MacOS/StudioMCP"
    }
  }
}

The plugin README also says StudioMCP can live in ~/Applications/RobloxStudio.app, and that Claude starts the server through /bin/sh or cmd.exe. The Creator Hub page checked on 4 November 2026 does not publish a Linux command.

CLI command

Some clients want a command instead of a JSON file. Roblox's page gives these two.

cmd.exe /c %LOCALAPPDATA%\Roblox\mcp.bat

/Applications/RobloxStudio.app/Contents/MacOS/StudioMCP

Check that it connected

1. Open Assistant.
2. Click …, then Manage MCP Servers.
3. Under Enable Studio as MCP server, look for the green indicator.

How do I connect Claude Code to Roblox Studio?

Claude Code is on the Creator Hub quick connect list, and it is also an install target in the October 2026 plugin README. Use either path. Both end at the same Studio server.

Quick connect

1. Turn on Enable Studio as MCP server, using the steps above.
2. Open Assistant Settings, then MCP Servers, then Quick connect.
3. Turn on Claude Code.
4. If Claude Code is not listed, install it and restart Studio.
5. Confirm the green indicator.

Official plugin

The plugin README says to run /plugin in Claude Code, search for Roblox Studio, and install it. Then ask the assistant, "Get me set up with Roblox Studio." You still turn the MCP switch on yourself. The README says the plugin does not read your password.

Check it by asking the assistant to list your open Studio windows. In Claude Code, /mcp shows plugin:roblox-studio:macos and plugin:roblox-studio:windows. The README says only the entry for your operating system connects, so the other one showing as failed is expected.

If you are not using quick connect or the plugin, add the JSON configuration above. On Windows the command is cmd.exe and mcp.bat. On macOS it is StudioMCP inside Roblox Studio.app.

How do I connect Codex to Roblox Studio?

The Creator Hub quick connect list names Codex CLI. The plugin README covers Codex CLI and the ChatGPT desktop app, and it adds one switch that quick connect's general list does not spell out.

Quick connect for Codex CLI

1. Turn on Enable Studio as MCP server.
2. Open Assistant Settings, then MCP Servers, then Quick connect.
3. Turn on Codex CLI.
4. If it is not listed, install Codex CLI and restart Studio.

Official plugin

codex plugin marketplace add Roblox/roblox-studio-agent-plugin

1. Run the marketplace command above.
2. Open /plugins, install Roblox Studio, and start a new thread with /new.
3. In Studio, under Quick Connect, turn on ChatGPT (codex).
4. Restart ChatGPT or open a new Codex thread.

The plugin README's check is `codex mcp list`, which should show Roblox_Studio. For the ChatGPT desktop app, the same README says to open Plugins, find Roblox Studio, install it, and start a new chat, then turn on ChatGPT (codex) under Quick Connect.

A Developer Forum reply on 18 September 2026 noted that OpenAI had renamed the desktop app to ChatGPT, which is why "Codex" and "ChatGPT" show up as two names for related clients. The manual JSON above is what Urukeli pointed people at while that detection bug was open. See the troubleshooting section.

How do I connect Cursor to Roblox Studio?

Cursor is on the Creator Hub quick connect list. The October 2026 plugin README does not list a Cursor install. This section stays with what the Creator Hub page actually says.

1. Install the latest Roblox Studio and Cursor.
2. Turn on Enable Studio as MCP server.
3. Open Assistant Settings, then MCP Servers, then Quick connect.
4. Turn on Cursor.
5. If Cursor is not in the list, install it and restart Studio.
6. Confirm the green indicator under Enable Studio as MCP server.

If you attach Cursor by a config file instead of quick connect, use the Windows or macOS JSON block in the first section. Roblox says to add Roblox_Studio to the mcpServers object. The Creator Hub page checked on 4 November 2026 does not name the path of Cursor's config file.

How do I connect Claude Desktop to Roblox Studio?

Claude Desktop is its own name on the Creator Hub quick connect list, separate from Claude Code. The plugin README also has a Cowork install for the Claude desktop app. They are two documented doors onto the same server.

Quick connect

1. Turn on Enable Studio as MCP server.
2. Open Assistant Settings, then MCP Servers, then Quick connect.
3. Turn on Claude Desktop.
4. If Claude Desktop is not listed, install it and restart Studio.
5. Confirm the green indicator.

Cowork plugin

The plugin README says: in the Claude desktop app, go to Customize, then Plugins, find Roblox Studio, and install it. Then ask, "Get me set up with Roblox Studio." You turn the MCP switch on yourself. The README says the plugin contains no code of its own.

claude.ai in the browser cannot connect. The plugin README says the server runs on your computer, so the web app can help you plan and write Luau but cannot attach to Studio. On Windows, Claude Desktop installed as a packaged app is also the client in the 401 report below, because StudioMCP then runs inside that app's private folder.

What is Roblox's October 2026 agent plugin?

The official plugin is Roblox's package for Claude (Claude Code and Cowork) and ChatGPT (the desktop app and Codex). The repo history shows plugin v0.2.1 on 7 October 2026 and a Windows sandbox note on 15 October 2026. It is not a separate MCP server.

• The README says the plugin contains no code of its own, only configuration and skill instructions.
• It starts Studio's server: StudioMCP in RobloxStudio.app on macOS, in /Applications or ~/Applications, or %LOCALAPPDATA%\Roblox\mcp.bat on Windows.
• After you approve once, it may download the Studio installer from setup.rbxcdn.com, check Roblox's signature, and run it. It may also open Studio and, for ChatGPT and Codex, register the Roblox_Studio server.
• It asks whether you are signed in rather than checking, and the README says it never handles your password.
• It sends tool results your assistant reads, such as scripts and console output, to your AI provider as part of the conversation. It says it collects nothing itself.

Roblox's older open-source server, Roblox/studio-rust-mcp-server, warns that it is no longer actively developed and points people at the built-in server. Its README still links a Windows executable for that old server. Use mcp.bat or StudioMCP from the Studio install instead.

How do I target more than one Studio window?

The Creator Hub page says every tool call takes a studio_id. Call list_roblox_studios for each open place's name, instance id and place id, then pass that id on later calls. Local places with no place id are listed by name only.

Roblox announced this on the Developer Forum on 19 August 2026. The post says to restart the AI client once after Studio updates so the client picks up the new tools, and that Assistant Settings shows which AI clients are connected.

Roblox Studio MCP not working?

Start with the three checks on the Creator Hub page. The cases under them are from Developer Forum threads, with the fix each thread actually settled on.

Roblox's own checklist

• Restart both Roblox Studio and the MCP client.
• Check that the command or binary path exists. On Windows that is %LOCALAPPDATA%\Roblox\mcp.bat. On macOS it is StudioMCP inside Roblox Studio.app.
• Check the JSON. A missing comma or bracket stops the file from loading.

401 Unauthorized from StudioMCP

A report opened on 27 October 2026 describes Studio logging `[DFLog::WebSocketTraceError]` against `http://localhost:13469/studio` with `401 Unauthorized`, and a dialog that said Studio could not authenticate with the MCP server. Restarting, signing out, and a new auth.token did not help. Verbose logs showed the helper rejecting the socket because Studio sent no Authorization header. The thread.

The reporter was launching the server from Claude Desktop, an MSIX app on Windows, so StudioMCP wrote its token inside Claude's private package folder. Studio, outside that sandbox, reads `%LOCALAPPDATA%\Roblox\StudioMCP\auth.token`. On 1 November 2026 the reporter confirmed the fix that kept the token check on:

1. Quit Claude Desktop, Claude Code and Codex, and stop every StudioMCP process.
2. Find the auth.token file Claude's packaged app wrote under its private folder.
3. Copy that file to %LOCALAPPDATA%\Roblox\StudioMCP\auth.token.
4. Remove any ClientAppSettings.json override that turns token enforcement off.
5. Start the AI client again, then Studio, and check the green indicator.

shibaxixi, replying for the team, said enforcement had been turned on around 27 October 2026 and that a product fix was still to come. The same thread's earlier flag, which turns the token check off, is described by the reporter as letting any local program connect. The reporter removed that override once the token was in the folder Studio reads. This guide does not repeat the flag.

Codex or the ChatGPT app is not detected

On 10 September 2026 a report said that after the Studio build published on 9 September 2026, the ChatGPT desktop app was not detected, while Claude Code was. Reinstalling Studio, clearing Assistant settings, and re-enabling the switch did not fix that report. Urukeli replied that the team was looking into it and pointed at the manual setup under the quick-connect panel. On 7 October 2026 the original reporter said the ChatGPT app connected on their Windows 11 PC. The thread.

A separate reply, from someone whose Codex thread assumed the server was down, said this prompt reconnected it: tell Codex to inspect its available MCP tools and call a read-only Roblox Studio tool, and not to assume the server is disconnected. The plugin README's matching step is still to turn on ChatGPT (codex) under Quick Connect and start a new thread.

Claude Code around 26 September 2026

A report on 26 September 2026 said Studio MCP worked on Claude Code 2.1.280 and failed on 2.1.281 and later. yipiokay replied that a Claude Code change around 25 September broke the connection, gave `MCP_PROTOCOL_NEGOTIATION=legacy claude` as a temporary workaround, and posted on 27 September that a Studio fix had shipped and to wait for Restart Studio. A follow-up that day said it worked again. That workaround was for the days before the fix. The thread.

Assistant says the user is not authenticated

A different 401, on apis.roblox.com for the Assistant conversation endpoint, showed the message "User is not authenticated." The person who opened that report later said logging out of Studio and back in fixed Assistant, and that the Claude path they had copied out of Studio was wrong. That is the Assistant account session, not the localhost MCP socket above. The thread.