JetBrains MCP Proxy Server

What is JetBrains MCP Proxy Server about?

The proxy server acts as a bridge between MCP‑enabled clients (e.g., VS Code extensions, Claude Desktop, LibreChat) and JetBrains IDEs such as IntelliJ IDEA, PyCharm, WebStorm, and Android Studio. It launches a lightweight Node.js process that relays HTTP/STDIO calls to the IDE’s built‑in MCP endpoint.

How to use JetBrains MCP Proxy Server?

1. Install the MCP Server plugin in the target JetBrains IDE via the Marketplace (plugin id: 26071-mcp-server).
2. Add a server entry to the client configuration (VS Code, Claude Desktop, etc.) that invokes npx -y @jetbrains/mcp-proxy.
3. Optionally set environment variables (IDE_PORT, HOST, LOG_ENABLED) to target a specific IDE instance or enable logging.
4. Start the client; the proxy will launch, connect to the IDE, and expose MCP endpoints on http://127.0.0.1:6365 (default).

Key features of JetBrains MCP Proxy Server

• Zero‑install client integration – use npx to run the proxy without a global package install.
• Cross‑IDE support – works with all IntelliJ‑based editors, including Android Studio.
• Configurable target – specify custom IDE host/port via HOST and IDE_PORT env vars.
• Logging toggle – enable detailed logs with LOG_ENABLED=true.
• Compatibility with containerised workflows – can be run from Docker or other external processes.

Use cases of JetBrains MCP Proxy Server

• Providing code‑completion, documentation, and analysis features from external AI assistants (e.g., Claude Desktop) within JetBrains IDEs.
• Enabling headless or container‑based clients (LibreChat, Cline, etc.) to query IDE‑internal tooling via MCP.
• Development of custom extensions that need to call IDE services without writing a native plugin.
• Testing and debugging of MCP‑based integrations in a sandboxed environment.

FAQ from the JetBrains MCP Proxy Server

• Which Node.js version is required? Node 18 or later; Node 16 is unsupported.
• Why is the repository deprecated? Core functionality is now built into IntelliJ‑based IDEs since version 2025.2; the proxy remains useful for external clients that still rely on the NPM package.
• How to make the proxy reachable from Docker? Enable “Can accept external connections” in the IDE debugger settings and set IDE_PORT and HOST to the machine’s LAN IP.
• Can I use the proxy without the JetBrains plugin? No; the plugin supplies the IDE‑side MCP endpoint that the proxy communicates with.
• Where to report bugs after the built‑in integration? Use JetBrains YouTrack with the MCP subsystem.

⚠️ Deprecated

This repository is no longer maintained. The core functionality has been integrated into all IntelliJ-based IDEs since version 2025.2. The built-in functionality works with SSE and JVM-based proxy (for STDIO) so this NPM package is no longer required.

Migration: Please refer to the official documentation for details on using the built-in functionality.

Issues & Support: For bugs or feature requests related to the built-in MCP functionality, please use the JetBrains YouTrack.

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:

"env": {
  "IDE_PORT": "<port of IDE's built-in webserver>"
}

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

"env": {
  "HOST": "<host/address of IDE's built-in webserver>"
}

To enable logging add:

"env": {
  "LOG_ENABLED": "true"
}

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