How do I connect Claude Code, Codex or Cursor to Roblox Studio?
The steps below are the ones on Roblox's Creator Hub page Connect to the Roblox Studio MCP server, which was last updated 3 November 2026, and on the README of Roblox/roblox-studio-agent-plugin. Paths and toggles that those pages do not publish are not filled in here.
Studio's MCP 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 clients can read and modify that place, so only connect a client you trust. The web apps at claude.ai and ChatGPT cannot attach, because the server is local. The plugin README says that limit in those words.
Turn the server on
- Install the latest Roblox Studio and the client you want to use.
- Open Assistant.
- Click …, then Manage MCP Servers.
- Turn on Enable Studio as MCP server.
When a client connects, the same panel shows a green indicator and a count of connected clients. The plugin README's manual path uses the same switch, worded as …, then Settings, then MCP Servers, with Manage MCP Servers noted as the older label.
Quick connect for Claude Code, Codex and Cursor
Roblox's quick connect list is Antigravity, Codex CLI, Claude Code, Claude Desktop, Cursor, Gemini CLI and Visual Studio Code.
- Go to Assistant Settings, then MCP Servers.
- Open the Quick connect dropdown. It lists supported clients installed on that computer.
- Turn on Claude Code, Codex CLI or Cursor.
- If the client is missing from the list, install it and restart Studio.
For ChatGPT and Codex, the plugin README adds one more switch: in that same pane, under Quick Connect, turn on ChatGPT (codex), then restart ChatGPT or open a new Codex thread.
JSON configuration
If quick connect does not list your client, Roblox publishes this stdio configuration. Add Roblox_Studio to the mcpServers object you already have. A missing comma between entries makes the file invalid.
Windows, from the Creator Hub
{
"mcpServers": {
"Roblox_Studio": {
"command": "cmd.exe",
"args": [
"/c",
"%LOCALAPPDATA%\\Roblox\\mcp.bat"
]
}
}
}macOS, from the Creator Hub
{
"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 3 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.
Windows
cmd.exe /c %LOCALAPPDATA%\Roblox\mcp.batmacOS
/Applications/RobloxStudio.app/Contents/MacOS/StudioMCPOfficial agent plugin, October 2026
The official plugin is Roblox's own package for Claude (Claude Code and Cowork) and ChatGPT (the desktop app and Codex). The repo's October 2026 history includes plugin v0.2.1 on 7 October and a Windows sandbox note on 15 October. The README says the plugin contains no code of its own, only configuration and skill instructions, and that it starts Studio's MCP server rather than a third-party binary.
- Claude Code: run /plugin, search for Roblox Studio, and install it.
- Claude desktop (Cowork): Customize, then Plugins, then Roblox Studio.
- ChatGPT desktop: Plugins, then Roblox Studio, then start a new chat.
- Codex CLI: add the marketplace, open /plugins, install Roblox Studio, and start a thread with /new.
Codex CLI
codex plugin marketplace add Roblox/roblox-studio-agent-pluginThe README's next step is to ask the assistant, "Get me set up with Roblox Studio." It can download the Studio installer from setup.rbxcdn.com after you approve, and it says it checks Roblox's signature before running that installer. You still turn the MCP switch on yourself. It says it does not read your password. Check the connection by asking it to list your open Studio windows. In Claude Code, /mcp shows both a macOS and a Windows plugin entry, and the one for the other operating system failing is expected. In Codex, `codex mcp list` should show Roblox_Studio.
More than one Studio window
The Creator Hub page says every tool call takes a studio_id. Call list_roblox_studios to see each open place's name, instance id and place id, then pass that id on later calls. Roblox announced this routing on the Developer Forum on 19 August 2026 and said to restart the AI client once after Studio updates so the client picks up the new tools. Assistant Settings shows which AI clients are connected.
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. This page does not use that download.
Roblox Studio MCP not working?
Roblox's own troubleshooting list, on the same Creator Hub page, is short. If the server does not show up or the tools are missing: restart Studio and the MCP client, check that the command or binary path exists, and check the JSON for a missing comma or bracket.
401 Unauthorized from StudioMCP
A Developer Forum bug report opened on 27 October 2026 describes a different failure. Studio logged `[DFLog::WebSocketTraceError]` against `http://localhost:13469/studio` with `401 Unauthorized`, and a dialog 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 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`.
The fix that kept the token check on, confirmed in that thread on 1 November 2026, was to copy auth.token from Claude's private folder into the real `%LOCALAPPDATA%\Roblox\StudioMCP` folder and restart. 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 workaround, a ClientAppSettings.json flag that sets token enforcement off, is described by the reporter as turning the check off for any local program. The reporter removed that override once the token was in the folder Studio actually reads. This page does not repeat the flag.
Codex or ChatGPT not detected
On 10 September 2026 a Developer Forum 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 Codex quick-connect 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. A separate reply, from someone whose Codex thread assumed the server was down, said a prompt that tells the model to inspect its MCP tool list and call a read-only Studio tool reconnected it. The plugin README's matching step is still: turn on ChatGPT (codex) under Quick Connect, then start a new thread.
Claude Code versions 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.
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.
Should I download a Roblox MCP tool from a GitHub search?
On 3 November 2026 a GitHub repository search for roblox mcp returned 277 repositories. Filtering that search to repositories created on 22 September 2026 returned 19. Seventeen of those 19 had zero forks. The highest star counts that day sat in a tight band, 68 to 76. The eight most-starred were opened file by file: each held a README, an index.html, two SVG images and a workflow file, and no application source. Eighteen of the nineteen READMEs led with a Download badge pointing at a GitHub Pages site.
Those pages were not run. Several were obfuscated HTML with a hidden payload and a script that decodes it, titled My Page, rather than a project document. If a search result's pitch is a Download badge, close it. Do not run a Windows .exe offered as an AI tool for Roblox Studio. Studio's current server is already installed with Studio: mcp.bat on Windows and StudioMCP inside Roblox Studio on macOS. Roblox's official plugin README says the plugin contains no code of its own.
The exception worth knowing about is Roblox's own retired server. Its README still links rbx-studio-mcp.exe and, in the same file, says that project is no longer actively developed. Prefer the built-in server. The Windows exe named in the RbxSync README further down is that project's own release binary, on that repository's GitHub releases, and the license there is proprietary. It is not one of the 22 September lookalikes.
