PluggedIn MCP server for AI agents

The plugged.in MCP Proxy Server is a middleware solution that aggregates multiple Model Context Protocol (MCP) servers into a unified interface. It allows you to access tools from different MCP servers through a single connection point, with features like smart discovery caching, RAG search capabilities, and notification support.

Installation

Prerequisites

Node.js 18+ (recommended v20+)
An API key from the plugged.in App (available at plugged.in/api-keys)

Basic Installation

# Install and run with npx
npx -y @pluggedin/mcp-proxy@latest --pluggedin-api-key YOUR_API_KEY

Configuration for Different MCP Clients

Claude Desktop

Add to your Claude Desktop configuration:

{
  "mcpServers": {
    "pluggedin": {
      "command": "npx",
      "args": ["-y", "@pluggedin/mcp-proxy@latest"],
      "env": {
        "PLUGGEDIN_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

Cline

Add to your Cline configuration:

{
  "mcpServers": {
    "pluggedin": {
      "command": "npx",
      "args": ["-y", "@pluggedin/mcp-proxy@latest"],
      "env": {
        "PLUGGEDIN_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

Cursor

For Cursor, use command-line arguments:

npx -y @pluggedin/mcp-proxy@latest --pluggedin-api-key YOUR_API_KEY

Configuration Options

Environment Variables

Variable	Description	Required	Default
`PLUGGEDIN_API_KEY`	API key from plugged.in App	Yes	-
`PLUGGEDIN_API_BASE_URL`	Base URL for plugged.in App	No	`https://plugged.in`

Command Line Arguments

Command line arguments override environment variables:

npx -y @pluggedin/mcp-proxy@latest --pluggedin-api-key YOUR_API_KEY --pluggedin-api-base-url https://your-custom-url.com

Transport Options

Option	Description	Default
`--transport <type>`	Transport type: `stdio` or `streamable-http`	`stdio`
`--port <number>`	Port for Streamable HTTP server	`12006`
`--stateless`	Enable stateless mode for Streamable HTTP	`false`
`--require-api-auth`	Require API key for Streamable HTTP requests	`false`

For a complete list of options:

npx -y @pluggedin/mcp-proxy@latest --help

HTTP Server Mode

The proxy can run as an HTTP server instead of STDIO, enabling web-based access:

# Run as HTTP server on default port (12006)
npx -y @pluggedin/mcp-proxy@latest --transport streamable-http --pluggedin-api-key YOUR_API_KEY

# Custom port
npx -y @pluggedin/mcp-proxy@latest --transport streamable-http --port 8080 --pluggedin-api-key YOUR_API_KEY

# With authentication required
npx -y @pluggedin/mcp-proxy@latest --transport streamable-http --require-api-auth --pluggedin-api-key YOUR_API_KEY

# Stateless mode (new session per request)
npx -y @pluggedin/mcp-proxy@latest --transport streamable-http --stateless --pluggedin-api-key YOUR_API_KEY

HTTP Endpoints

POST /mcp - Send MCP messages
GET /mcp - Server-sent events stream
DELETE /mcp - Terminate session
GET /health - Health check endpoint

Session Management

In stateful mode (default), use the mcp-session-id header to maintain sessions:

# First request creates a session
curl -X POST http://localhost:12006/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","method":"tools/list","id":1}'

# Subsequent requests use the same session
curl -X POST http://localhost:12006/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -H "mcp-session-id: YOUR_SESSION_ID" \
  -d '{"jsonrpc":"2.0","method":"tools/call","params":{"name":"tool_name"},"id":2}'

Authentication

When using --require-api-auth, include your API key as a Bearer token:

curl -X POST http://localhost:12006/mcp \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json, text/event-stream" \
  -d '{"jsonrpc":"2.0","method":"ping","id":1}'

Docker Usage

Building the Image

docker build -t pluggedin-mcp-proxy:latest .

Running the Container

STDIO Mode (Default)

docker run -it --rm \
  -e PLUGGEDIN_API_KEY="YOUR_API_KEY" \
  -e PLUGGEDIN_API_BASE_URL="YOUR_API_BASE_URL" \
  --name pluggedin-mcp-container \
  pluggedin-mcp-proxy:latest

Streamable HTTP Mode

docker run -d --rm \
  -e PLUGGEDIN_API_KEY="YOUR_API_KEY" \
  -e PLUGGEDIN_API_BASE_URL="YOUR_API_BASE_URL" \
  -p 12006:12006 \
  --name pluggedin-mcp-http \
  pluggedin-mcp-proxy:latest \
  --transport streamable-http --port 12006

Testing with MCP Inspector

npx @modelcontextprotocol/inspector docker://pluggedin-mcp-container

Available Tools

The proxy provides two categories of tools:

Built-in Static Tools (Always Available)

pluggedin_discover_tools - Smart discovery with caching for instant results
pluggedin_rag_query - RAG search across your documents
pluggedin_send_notification - Send notifications with optional email delivery

Dynamic MCP Tools (From Connected Servers)

These tools come from your configured MCP servers and can be turned on/off through the plugged.in App.

Discovery Tool Usage

# Quick discovery - returns cached data instantly
pluggedin_discover_tools()

# Force refresh - shows current tools + runs background discovery  
pluggedin_discover_tools({"force_refresh": true})

# Discover specific server
pluggedin_discover_tools({"server_uuid": "uuid-here"})

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "pluggedin" '{"command":"npx","args":["-y","@pluggedin/mcp-proxy@latest"],"env":{"PLUGGEDIN_API_KEY":"YOUR_API_KEY"}}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "pluggedin": {
            "command": "npx",
            "args": [
                "-y",
                "@pluggedin/mcp-proxy@latest"
            ],
            "env": {
                "PLUGGEDIN_API_KEY": "YOUR_API_KEY"
            }
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "pluggedin": {
            "command": "npx",
            "args": [
                "-y",
                "@pluggedin/mcp-proxy@latest"
            ],
            "env": {
                "PLUGGEDIN_API_KEY": "YOUR_API_KEY"
            }
        }
    }
}

3. Restart Claude Desktop for the changes to take effect