MCP Proxy Server

An MCP proxy server that aggregates and serves multiple MCP resource servers through a single interface. This server acts as a central hub that can:

- Connect to and manage multiple MCP resource servers
- Expose their combined capabilities through a unified interface
- Handle routing of requests to appropriate backend servers
- Aggregate responses from multiple sources

Features

Resource Management

- Discover and connect to multiple MCP resource servers - Aggregate resources from all connected servers - Maintain consistent URI schemes across servers - Handle resource routing and resolution

Tool Aggregation

- Expose tools from all connected servers - Route tool calls to appropriate backend servers - Maintain tool state and handle responses

Prompt Handling

- Aggregate prompts from all connected servers - Route prompt requests to appropriate backends - Handle multi-server prompt responses

Configuration

The server requires a JSON configuration file that specifies the MCP servers to connect to. Copy the example config and modify it for your needs:

cp config.example.json config.json

Example config structure:

{

  "servers": [

    {

      "name": "Server 1",

      "transport": {

        "command": "/path/to/server1/build/index.js"

      }

    },

    {

      "name": "Server 2",

      "transport": {

        "command": "server2-command",

        "args": ["--option1", "value1"]

      }

    }

  ]

}

The config file must be provided when running the server:

MCP_CONFIG_PATH=./config.json mcp-proxy-server

Development

Install dependencies:

npm install

Build the server:

npm run build

For development with auto-rebuild:

npm run watch

Installation

To use with Claude Desktop, add the server config:

On MacOS: ~/Library/Application Support/Claude/claude_desktop_config.json
On Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "mcp-proxy": {
      "command": "/path/to/mcp-proxy-server/build/index.js",
      "env": {
        "MCP_CONFIG_PATH": "/absolute/path/to/your/config.json"
      }
    }
  }
}

Debugging

Since MCP servers communicate over stdio, debugging can be challenging. We recommend using the MCP Inspector, which is available as a package script:

npm run inspector

The Inspector will provide a URL to access debugging tools in your browser.