node-red-contrib-mcp-tools 1.0.1

Node-RED component for executing MCP (Model Context Protocol)

npm install node-red-contrib-mcp-tools

Node-RED MCP Tools Component

This is a Node-RED component that enables the execution of MCP Servers (Model Context Protocol).

Installation

Installation via npm

1. Open the Node-RED user interface in your browser (e.g., http://localhost:1880).
2. Click the menu icon (three horizontal lines) in the top-right corner.
3. Select Manage Palette from the dropdown menu.
4. Go to the Install tab.
5. In the search bar, type node-red-contrib-mcp-tools and click Install.

Alternatively, install via the terminal:

npm install node-red-contrib-mcp-tools
### Installation via npm

It will appear in the function category.

Configuration

1. First Step: Run the MCP Host

Before starting, you need to have the MCP Host running. Use the code available in the mcp-host folder.

The MCP Host is a Node.js application responsible for mediating communication between Node-RED and the MCP Server.

You can run an MCP Server in different ways:

• 💻 Locally on your machine;
• 🐳 In a Docker container,
• 🌐 Remotely, connecting to an MCP Host already available on another server.

Running locally:

cd mcp-host
npm install
npm start

The server will run by default on port 3000.

2. Component Configuration

• Server URL: URL where the MCP service is running (e.g., http://localhost:3000) or http://host.docker.internal:3000 if running with Docker.
• Default Prompt: Optional prompt that will be used if not provided in the message.

For more information on running with Docker Compose, see: https://github.com/moises-paschoalick/node-red-mcp-server

Usage

Inputs

• msg.payload (string): The prompt to be sent to the MCP tools.
• msg.prompt (string): Specific prompt (overrides the default prompt).

Outputs

• msg.payload (string): The response from the MCP tools.
• msg.mcpResult (object): Detailed object containing:
  • success: Whether the execution was successful.
  • response: The tool's response.
  • toolsUsed: Array of tools used.
  • messages: Complete conversation history.
  • originalPrompt: The original prompt sent.

Example Flow

[
    {
        "id": "inject1",
        "type": "inject",
        "name": "Test MCP",
        "props": [
            {
                "p": "payload",
                "v": "display user information",
                "vt": "str"
            }
        ],
        "repeat": "",
        "crontab": "",
        "once": false,
        "onceDelay": 0.1,
        "topic": "",
        "x": 100,
        "y": 100,
        "wires": [["mcp1"]]
    },
    {
        "id": "mcp1",
        "type": "mcp-tools",
        "name": "MCP Tools",
        "serverUrl": "http://localhost:3000",
        "prompt": "",
        "timeout": 30000,
        "x": 300,
        "y": 100,
        "wires": [["debug1"]]
    },
    {
        "id": "debug1",
        "type": "debug",
        "name": "Result",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "true",
        "targetType": "full",
        "x": 500,
        "y": 100,
        "wires": []
    }
]

Features

• ✅ Execution of prompts via the MCP tools component.
• ✅ Support for dynamic prompts via message.
• ✅ Flexible server configuration.
• ✅ Visual node status (running, success, error).
• ✅ Detailed output with tools used.

Troubleshooting

Connection Error

• Check if the MCP server is running.
• Confirm the server URL in the configuration.
• Ensure no firewall is blocking the connection.

Timeout

• Increase the timeout value if operations take longer.
• Check the MCP server's performance.

Parsing Error

• Verify if the server is returning valid JSON.
• Confirm that the MCP server is functioning correctly.

License

MIT