What is JetBrains MCP Proxy Server

JetBrains MCP Proxy Server is a tool designed to proxy requests from clients to JetBrains Integrated Development Environments (IDEs). It streamlines communication between various client applications and JetBrains IDEs, allowing for enhanced functionality and integration.

Use cases

The MCP Proxy Server can be utilized in various scenarios including integration with external clients like Claude Desktop, enabling tools that need to access IDE functionality, and supporting development workflows in environments such as Docker containers. It allows for easy connection to multiple IDE instances and provides flexibility in managing requests.

How to use

To use the MCP Proxy Server, install the MCP Server plugin in a JetBrains IDE and configure the settings in Visual Studio Code or Claude Desktop. Configuration requires specifying the command and arguments to run the proxy, and may include additional settings like port and host for IDE access. Follow the specific JSON structure for your preferred client application to ensure proper setup.

Key features

Key features of the MCP Proxy Server include the ability to connect to multiple JetBrains IDEs, support for external connections, configurable logging options, and the capability to specify different host addresses and ports for IDE connections. It also provides troubleshooting tips for common issues related to Node.js compatibility and connection settings.

Where to use

The MCP Proxy Server is primarily used in development environments that involve JetBrains IDEs, such as IntelliJ IDEA, PyCharm, or GoLand. It is beneficial in settings that require interaction between JetBrains products and other applications or clients, providing a bridge for functionalities within IDEs to be accessed externally.

JetBrains MCP Proxy Server

The server proxies requests from client to JetBrains IDE.

Install MCP Server plugin

https://plugins.jetbrains.com/plugin/26071-mcp-server

VS Code Installation

For one-click installation, click one of the install buttons below:

Manual Installation

Add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open User Settings (JSON).

{
  "mcp": {
    "servers": {
      "jetbrains": {
        "command": "npx",
        "args": [
          "-y",
          "@jetbrains/mcp-proxy"
        ]
      }
    }
  }
}

Optionally, you can add it to a file called .vscode/mcp.json in your workspace:

{
  "servers": {
    "jetbrains": {
      "command": "npx",
      "args": [
        "-y",
        "@jetbrains/mcp-proxy"
      ]
    }
  }
}

Usage with Claude Desktop

To use this with Claude Desktop, add the following to your claude_desktop_config.json.
The full path on MacOS: ~/Library/Application\ Support/Claude/claude_desktop_config.json, on Windows: %APPDATA%/Claude/claude_desktop_config.json.

{
  "mcpServers": {
    "jetbrains": {
      "command": "npx",
      "args": [
        "-y",
        "@jetbrains/mcp-proxy"
      ]
    }
  }
}

After installing the MCP Server Plugin, and adding the JSON to the config file, restart Claude Desktop, and make sure the Jetbrains product is open before restarting Claude Desktop.

Configuration

If you’re running multiple IDEs with MCP server and want to connect to the specific one, add to the MCP server configuration:

By default, we connect to IDE on 127.0.0.1 but you can specify a different address/host:

To enable logging add:

Troubleshooting

Node.js Version Requirements

Problem: Error message: Cannot find module 'node:path'

Solution:
MCP Proxy doesn’t work on Node 16.
Upgrade your Node.js installation to version 18 or later. Make sure that command in config points to the correct Node.js version.
Try to use the full path to the latest version of NodeJS.

MacOS: Plugin Unable to Detect Node.js Installed via nvm

Problem: On MacOS, if you have Node.js installed through nvm (Node Version Manager), the MCP Server Plugin might be unable to detect your Node.js installation.

Solution: Create a symbolic link in /usr/local/bin pointing to your nvm npx executable:

which npx &>/dev/null && sudo ln -sf "$(which npx)" /usr/local/bin/npx

This one-liner checks if npx exists in your path and creates the necessary symbolic link with proper permissions.

Using MCP with External Clients or Docker Containers (LibreChat, Cline, etc.)

Problem: When attempting to connect to the JetBrains MCP proxy from external clients, Docker containers, or third-party applications (like LibreChat), requests to endpoints such as http://host.docker.internal:6365/api/mcp/list_tools may return 404 errors or fail to connect.
Solution: There are two key issues to address:

1. Enable External Connections:

In your JetBrains IDE, enable “Can accept external connections” in the Settings | Build, Execution, Deployment | Debugger.

2. Configure with LAN IP and Port:

Use your machine’s LAN IP address instead of host.docker.internal
Explicitly set the IDE_PORT and HOST in your configuration
Example configuration for LibreChat or similar external clients:

mcpServers:
  intellij:
    type: stdio
    command: sh
    args:
      - "-c"
      - "IDE_PORT=YOUR_IDEA_PORT HOST=YOUR_IDEA_LAN_IP npx -y @jetbrains/mcp-proxy"

Replace:

YOUR_IDEA_PORT with your IDE’s debug port (found in IDE settings)
YOUR_IDEA_LAN_IP with your computer’s local network IP (e.g., 192.168.0.12)

How to build

1. Tested on macOS
2. brew install node pnpm
3. Run pnpm build to build the project