If you've been attempting to set up an OpenRouter MCP Server connection using the Cline Extension in VSCode Insiders as an MCP Client, you might have encountered the frustrating "spawn npx ENOENT spawn npx ENOENT" error. Let's dive into what this error means, why it happens, and how to fix it.

Understanding the Error

After saving the cline_mcp_settings.json file, Cline tries to connect automatically with the server, and this is when the error surfaces. The "spawn npx ENOENT" error typically indicates that the system is unable to find the npx command. This can be due to a couple of main reasons.

Possible Causes

The primary reason for this error is likely that Node.js is not installed on your system. Since npx is a tool that comes with Node.js, without Node.js, the system has no way of recognizing the npx command. Another possibility is that even if Node.js is installed, the system's path might not be configured correctly to locate the npx executable.

Solutions

1. Install Node.js

First and foremost, make sure you have Node.js installed. One option to manage different Node.js versions is to use the Node Version Manager (NVM). This tool allows you to easily switch between different Node.js versions, which can be useful in various development scenarios. You can find instructions on installing NVM and Node.js according to your operating system on the official NVM website.

2. Install 'OpenRouter MCP Server' Globally

Once you have Node.js installed, open a PowerShell window and run the following command to install the OpenRouter MCP Server globally:

npm install -g @mcpservers/openrouterai

The -g flag ensures that the package is installed globally on your system, making it accessible from anywhere in the command line.

3. Edit the cline_mcp_settings.json File

Locate the cline_mcp_settings.json file and make the following changes:

  • Change the 'command': Set it to the path of your node.exe. For example, if Node.js is installed in the default location on a Windows machine, it would be something like C:\\Program Files\\nodejs\\node.exe.
  • Change the 'args': Update this to the path of @mcpservers/openrouterai. For instance, it could be C:\\Program Files\\nodejs\\node_modules\\@mcpservers\\openrouterai\\dist\\index.js.

Full MCP configuration

{
  "mcpServers": {
    "filesystem": {
      "command": "C:\\Program Files\\nodejs\\node.exe",
      "args": [
        "C:\\Users\\<my user>\\AppData\\Roaming\\npm\\node_modules\\@modelcontextprotocol\\server-filesystem\\dist\\index.js",
        "C:\\Users\\<my user>\\Projects"
      ]
    }
  }
}

By following these steps, you should be able to resolve the "spawn npx ENOENT spawn npx ENOENT" error and successfully establish a connection between Cline in VSCode Insiders and the OpenRouter MCP Server. Happy coding!