Invoice MCP Server

Instructions

Implementation Reference

• src/email-service.ts:5-80 (handler)

  The function implementing the actual email sending logic for the 'send_invoice_email' tool.

  export async function sendInvoiceEmail(
    invoiceData: InvoiceData,
    recipientEmail: string,
    customSubject?: string,
    customMessage?: string
  ): Promise<void> {
    // Check if email configuration is available
    const smtpConfig = {
      host: process.env.SMTP_HOST,
      port: parseInt(process.env.SMTP_PORT || '587'),
      secure: false,
      auth: {
        user: process.env.SMTP_USER,
        pass: process.env.SMTP_PASS,
      },
    };
  
    if (!smtpConfig.host || !smtpConfig.auth.user || !smtpConfig.auth.pass) {
      throw new Error('Email configuration missing. Please set SMTP_HOST, SMTP_USER, and SMTP_PASS environment variables.');
    }
  
    // Generate PDF
    const pdfPath = await generateInvoicePDF(invoiceData);
    const pdfBuffer = await fs.readFile(pdfPath);
  
    // Create transporter (fixed method name)
    const transporter = nodemailer.createTransport(smtpConfig);
  
    // Email content
    const subject = customSubject || `Invoice ${invoiceData.invoiceNumber} from ${invoiceData.company.name}`;
    
    const defaultMessage = `Dear ${invoiceData.billTo.name},
  
  Please find attached invoice ${invoiceData.invoiceNumber} dated ${invoiceData.date}.
  
  ${invoiceData.dueDate ? `Payment is due by ${invoiceData.dueDate}.` : ''}
  
  If you have any questions regarding this invoice, please don't hesitate to contact us.
  
  Thank you for your business!
  
  Best regards,
  ${invoiceData.company.name}
  ${invoiceData.company.phone ? `Phone: ${invoiceData.company.phone}` : ''}
  ${invoiceData.company.email ? `Email: ${invoiceData.company.email}` : ''}`;
  
    const message = customMessage || defaultMessage;
  
    // Send email
    const mailOptions = {
      from: {
        name: process.env.FROM_NAME || invoiceData.company.name,
        address: process.env.FROM_EMAIL || process.env.SMTP_USER!,
      },
      to: recipientEmail,
      subject,
      text: message,
      attachments: [
        {
          filename: `invoice-${invoiceData.invoiceNumber}.pdf`,
          content: pdfBuffer,
          contentType: 'application/pdf',
        },
      ],
    };
  
    await transporter.sendMail(mailOptions);
  
    // Clean up temporary PDF file
    try {
      await fs.unlink(pdfPath);
    } catch (error) {
      // Ignore cleanup errors
      console.warn('Failed to clean up temporary PDF file:', error);
    }
  }

• src/index.ts:159-175 (registration)

  The handler in the MCP server setup that invokes the 'sendInvoiceEmail' service function.

  case 'send_invoice_email': {
    const invoiceData = InvoiceDataSchema.parse(args.invoice_data);
    const recipientEmail = args.recipient_email as string;
    const subject = args.subject as string | undefined;
    const message = args.message as string | undefined;
    
    await sendInvoiceEmail(invoiceData, recipientEmail, subject, message);
    
    return {
      content: [
        {
          type: 'text',
          text: `Invoice sent successfully to ${recipientEmail}`,
        },
      ],
    };
  }

• src/index.ts:96-120 (schema)

  The MCP tool definition and input schema for 'send_invoice_email'.

    name: 'send_invoice_email',
    description: 'Create and send an invoice via email',
    inputSchema: {
      type: 'object',
      properties: {
        invoice_data: {
          type: 'object',
          description: 'Complete invoice data including company info, bill-to info, items, etc.',
        },
        recipient_email: {
          type: 'string',
          description: 'Email address to send the invoice to',
        },
        subject: {
          type: 'string',
          description: 'Optional custom email subject',
        },
        message: {
          type: 'string',
          description: 'Optional custom email message body',
        },
      },
      required: ['invoice_data', 'recipient_email'],
    },
  },