#!/usr/bin/env node
require('dotenv').config();
const nodemailer = require('nodemailer');
const { Server } = require('@modelcontextprotocol/sdk/server/index.js');
const { StdioServerTransport } = require('@modelcontextprotocol/sdk/server/stdio.js');
const {
CallToolRequestSchema,
ListToolsRequestSchema,
} = require('@modelcontextprotocol/sdk/types.js');
const fs = require('fs');
const path = require('path');
const LOG_DIR = path.join(__dirname, 'log');
// Ensure log directory exists
if (!fs.existsSync(LOG_DIR)) {
fs.mkdirSync(LOG_DIR);
}
// Function to log messages to a daily file
function logMessage(message, type = 'info') {
const now = new Date();
const date = now.toISOString().split('T')[0]; // YYYY-MM-DD
const logFileName = `${date}.log`;
const logFilePath = path.join(LOG_DIR, logFileName);
const timestamp = now.toISOString();
const logEntry = `[${timestamp}] [${type.toUpperCase()}] ${message}\n`;
fs.appendFile(logFilePath, logEntry, (err) => {
// Fail silently or use a backup logging method to avoid infinite loops if stderr is captured
});
// Do NOT console.log here as it interferes with Stdio transport
// console.error(message); // Only write to stderr if necessary
}
// Configure Nodemailer transporter
const transporter = nodemailer.createTransport({
host: process.env.SMTP_HOST,
port: parseInt(process.env.SMTP_PORT || '465'),
secure: process.env.SMTP_SECURE === 'true',
auth: {
user: process.env.SMTP_USER,
pass: process.env.SMTP_PASS,
},
});
// Function to send email
async function sendEmail(to, subject, text, html) {
try {
const mailOptions = {
from: process.env.MAIL_FROM,
to,
subject,
text,
html,
};
const info = await transporter.sendMail(mailOptions);
logMessage(`Email sent to ${to}: ${info.messageId}`, 'info');
return { success: true, messageId: info.messageId };
} catch (error) {
logMessage(`Error sending email to ${to}: ${error.message}`, 'error');
throw error;
}
}
// Initialize MCP Server
const server = new Server(
{
name: 'mail-mcp',
version: '1.0.0',
},
{
capabilities: {
tools: {},
},
}
);
// List Tools Handler
server.setRequestHandler(ListToolsRequestSchema, async () => {
try {
return {
tools: [
{
name: 'send_email',
description: 'Send an email using configured SMTP settings',
inputSchema: {
type: 'object',
properties: {
to: {
type: 'string',
description: 'Recipient email address',
},
subject: {
type: 'string',
description: 'Email subject',
},
text: {
type: 'string',
description: 'Plain text body of the email',
},
html: {
type: 'string',
description: 'HTML body of the email (optional)',
},
},
required: ['to', 'subject', 'text'],
},
},
],
};
} catch (error) {
logMessage(`Error listing tools: ${error.message}`, 'error');
throw error; // Re-throw so MCP knows something went wrong
}
});
// Call Tool Handler
server.setRequestHandler(CallToolRequestSchema, async (request) => {
try {
if (request.params.name === 'send_email') {
const { to, subject, text, html } = request.params.arguments;
logMessage(`Received send_email request for: ${to}`, 'info');
try {
const result = await sendEmail(to, subject, text, html);
return {
content: [
{
type: 'text',
text: JSON.stringify(result, null, 2),
},
],
};
} catch (error) {
logMessage(`Error executing send_email: ${error.message}`, 'error');
// Return a clean error response to the client
return {
content: [
{
type: 'text',
text: `Error sending email: ${error.message}`,
},
],
isError: true,
};
}
}
throw new Error(`Tool not found: ${request.params.name}`);
} catch (error) {
logMessage(`Unexpected error in CallToolRequest: ${error.message}`, 'error');
return {
content: [
{
type: 'text',
text: `Internal server error: ${error.message}`,
},
],
isError: true,
};
}
});
// Connect transport
async function run() {
try {
const transport = new StdioServerTransport();
await server.connect(transport);
logMessage('Mail MCP Server running on stdio', 'info');
} catch (error) {
logMessage(`Failed to start MCP server: ${error.message}`, 'error');
console.error(`Fatal error starting server: ${error.message}`);
process.exit(1);
}
}
run().catch((error) => {
logMessage(`Fatal error: ${error}`, 'error');
process.exit(1);
});
