MCP Gateway

A Node.js gateway app for connecting to an existing Mule MCPHub server and relaying messages via SSE and HTTP.

Note: This script does not start a Mule MCP server. It connects to an existing MCP server instance. The mcp.json file is used by MCP clients (such as Cursor and Claude for desktop) to connect to Mule servers, and is also used by this gateway for configuration.

Features

• Connects to an existing MCPHub server via Server-Sent Events (SSE)
• Relays messages to/from the MCPHub backend
• Uses a local mcp.json config for environment variables (shared with other MCP clients)

Prerequisites

• Node.js v14 or later
• An mcp.json configuration file (see below)

Setup

1. Clone the repository

2. Install dependencies:

   npm install

3. Create your mcp.json config: Place your mcp.json in a secure location and set the environment variable PATH_TO_MCP_JSON to its path if needed.

   Example mcp.json:

   {
     "mcpServers": {
       "timecamp": {
         "command": "node",
         "args": [
           "path to node gateway script"
         ],
         "env": {
           "MCPHUB_SERVER_URL": "https://mcp-timecamp.uk-e1.cloudhub.io/"
         }
       }
     }
   }

   • command: The command to run the gateway (usually node).
   • args: Arguments for the command (e.g., path to your gateway script).
   • env: Environment variables for the gateway process.

4. Set required environment variables:

   • MCPHUB_SERVER_URL (optional, defaults to http://0.0.0.0:8090)

Usage

Start the Gateway

npm start

The gateway will connect to the MCPHub server and begin relaying messages.

Project Structure

• index.js - Entry point, wires together config and gateway
• src/gateway.js - Main gateway logic
• src/logger.js - Logging utilities
• mcp.example.json - Example config for users
• mcp.json - Your environment/config file (location set by PATH_TO_MCP_JSON)

License

ISC