PlayCanvas Editor MCP Server

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An MCP server for automating the PlayCanvas Editor with an LLM. The MCP client is built into the Editor — no browser extension needed. Install the server into your MCP client of choice (Claude Code, Codex, Claude Desktop, Cursor, …) and connect the Editor to it.

Installation

Requires Node.js 22.18+. The server is published to npm as `@playcanvas/editor-mcp-server` — a self-contained, zero-dependency bundle — so every client below runs it with `npx`. Nothing to clone or build.

Claude Code

claude mcp add playcanvas -- npx -y @playcanvas/editor-mcp-server

To share the server with everyone working on a repo, commit a `.mcp.json` to the project root instead:

{
  "mcpServers": {
    "playcanvas": {
      "command": "npx",
      "args": ["-y", "@playcanvas/editor-mcp-server"]
    }
  }
}

Codex

The Codex CLI and the Codex app share `~/.codex/config.toml`, so one command covers both:

codex mcp add playcanvas -- npx -y @playcanvas/editor-mcp-server

> [!NOTE]

> On Windows, use `codex mcp add playcanvas -- cmd /c npx -y @playcanvas/editor-mcp-server`. If the server times out on first run (while `npx` downloads the package), raise `startup_timeout_sec` under `[mcp_servers.playcanvas]` in `~/.codex/config.toml`. ChatGPT itself only supports remote MCP connectors, so Codex is the OpenAI surface to use.

Claude Desktop

Go to `Claude` > `Settings` > `Developer` > `Edit Config` and add to `claude_desktop_config.json`:

{
  "mcpServers": {
    "playcanvas": {
      "command": "npx",
      "args": ["-y", "@playcanvas/editor-mcp-server"]
    }
  }
}

> [!NOTE]

> On Windows, use `"command": "cmd"` and `"args": ["/c", "npx", "-y", "@playcanvas/editor-mcp-server"]`.

Cursor

Select `File` > `Preferences` > `Cursor Settings` > `MCP` > `Add new global MCP server` and add the same JSON as for Claude Desktop.

Custom Port

The server listens for the Editor on WebSocket port `52000` by default. To change it, append `--port ` to the `npx` args and set the same port in the Editor's MCP popover.

Connecting the Editor

1. Open your project in the PlayCanvas Editor.

2. Click the MCP button at the bottom of the toolbar (below the Publish button).

3. Check that the port matches your MCP config (default `52000`) and click `CONNECT`.

You can now issue commands from your MCP client.

> [!NOTE]

> Only one Editor instance can be connected to the MCP server at a time.

> [!IMPORTANT]

> Chromium gates a public page's connection to `127.0.0.1` behind a local access permission (Chrome 142+, extended to WebSockets in Chrome 147) granted per origin, so allow it when prompted. In Chrome's site settings it is `Apps on device` (loopback) — `Local network` covers LAN addresses and is not required. Only the Editor needs it: the launch page is bridged through the Editor rather than opening a socket of its own. If the Editor sits on `Connecting`, open its site settings and allow it — a blocked connection fails silently and looks exactly like a server that isn't running.

Editor Driver Coverage

All tools act on the project open in the connected Editor. The server does not discover, select, create, delete, transfer, or administer projects, and project IDs are not tool inputs.

Asset transfers over 20 MiB use 1 MiB chunks. The server reads and writes local files incrementally, while the Editor spools uploads to browser storage and consumes downloads as streams instead of buffering the entire transfer in memory.

The Runtime tools drive a real Launch instance (the Editor's Launch button) so an agent can verify that a scene actually *runs*: screenshot the running app, read its console output, query live entity state, and inject keyboard/mouse/touch input. Allow pop-ups for the editor origin so `launch_start` can open the launch window — it reuses your existing PlayCanvas login session. The Editor relays `runtime:*` calls to that window, so it needs no local access permission of its own. Calling `launch_start` with no options adopts an app that is already running (`adopted: true` in the response) instead of restarting it; pass any option to force a fresh launch.

Every tool returns a consistent `{ data, meta }` envelope: `meta.status` is `ok` or `error` (with an actionable message), list tools paginate via `limit`/`offset` and `meta.nextCursor`, and mutating tools return the resulting entity/asset summaries so follow-up list calls are rarely needed.

Development

To hack on the server itself, ensure you have Node.js 22.18 or later installed. Follow these steps:

1. Clone the repository:

git clone https://github.com/playcanvas/editor-mcp-server.git
    cd editor-mcp-server

2. Install dependencies:

npm install

3. Start the server (Node runs the TypeScript source directly — no build step):

npm run watch

4. Point your MCP client at the checkout instead of the npm package with `"command": "node"` and `"args": ["/path/to/editor-mcp-server/src/server.ts"]`.

`npm run debug` starts the server under the MCP Inspector and `npm run build` produces the self-contained bundle that gets published.