MCP Send Email Service (from Notify.cx)

This is a Model Context Protocol (MCP) service that provides email sending capabilities through a server-side event (SSE) based API. The service is built using TypeScript, Express.js, the MCP SDK, and the Notify.cx API.

Project Overview

The project is a microservice that:

1. Implements the Model Context Protocol (MCP) for email sending functionality
2. Uses Server-Sent Events (SSE) for real-time communication
3. Provides a simple email sending API endpoint

Technical Stack

• Runtime: Node.js with TypeScript
• Main Dependencies:
  • @modelcontextprotocol/sdk: ^1.8.0 (MCP SDK for server implementation)
  • express: ^5.0.1 (Web server framework)
  • dotenv: ^16.4.7 (Environment variable management)
  • zod: ^3.24.2 (Schema validation)
• Development Dependencies:
  • TypeScript and related type definitions
  • ts-node for TypeScript execution

Setup Instructions

1. Create a MCP server configuration file (e.g., mcp.json).

To get MCPs to work with IDEs such as Cursor, they need an MCP server configuration file.

The MCP server configuration file is a JSON file that describes the MCP server and the tools it supports.

To add the MCP server config in Cursor, go to Cursor > Settings > MCP Servers and add the following:

{
  "mcpServers": {
    "email-sending-service": {
      "name": "email-sending-service",
      "version": "1.0.0",
      "url": "http://localhost:8080/sse",
      "env": {
        "NOTIFY_API_KEY": "<your-notify-api-key>"
      },
      "tools": [
        {
          "name": "send-email",
          "description": "Send an email using Notify",
          "url": "http://localhost:8080/send-email",
          "params": {
            "to": "string",
            "subject": "string",
            "message": "string"
          }
        }
      ]
    }
  }
}

1. Create a free Notify.cx account and get an API key.
2. Clone the repository
3. Install dependencies:

   npm install
   

4. Create a .env file with the following variables:

   NOTIFY_API_KEY=your_api_key_here
   

5. Start the server:

   npm start
   

The server will start on port 8080.

API Endpoints

The service exposes two main endpoints:

1. /sse (GET)

   • Establishes an SSE connection for real-time communication
   • Used by the MCP protocol for bidirectional communication

2. /send-email (POST)

   • Handles email sending requests
   • Requires a sessionId query parameter
   • Request body should contain email details (to, subject, message)

Email Sending Configuration

The service sends emails through a notify service endpoint (https://notify.cx/api/send-email) with the following parameters:

• From: sent-with@mcp.notify.cx
• To: (specified in request)
• Subject: (specified in request)
• Message: (specified in request)

MCP Tool Configuration

The service registers a single MCP tool named "send-email" with the following parameters:

• to: Email address (string)
• subject: Email subject line (string)
• message: Plain text email content (string)

Error Handling

The service includes comprehensive error handling for:

• Invalid email requests
• Failed email sending attempts
• Missing or invalid session IDs
• Network errors

Environment Variables

Required environment variables:

• NOTIFY_API_KEY: API key for the notification service

Development

To run the project in development mode:

npm start

The service uses ts-node to run TypeScript files directly.

Project Structure

• index.ts: Main server file containing MCP and Express setup
• send-email.ts: Email sending implementation
• package.json: Project dependencies and scripts
• .env: Environment variables (not committed to version control)
• tsconfig.json: TypeScript configuration

This project is a specialized email sending service that implements the Model Context Protocol, making it suitable for integration with AI models or other services that need email sending capabilities.