agent-11: Skill for Claude Code

SaaS Transactional Email

Capability

Implement reliable transactional email delivery for SaaS applications including templating, queuing, delivery tracking, and provider abstraction. Covers common email types: welcome, verification, password reset, notifications, and invoices.

Use Cases

• Welcome and onboarding emails
• Email verification and password reset
• Notification emails (activity alerts, reminders)
• Invoice and receipt emails
• Team invitation emails
• Digest and summary emails

Patterns

Email Service Abstraction

When to use: Decouple email sending from specific provider (Resend, SendGrid, etc.)

Implementation: Create provider-agnostic interface with consistent API.

// Email service interface
interface EmailService {
  send(options: SendEmailOptions): Promise<EmailResult>;
  sendBatch(emails: SendEmailOptions[]): Promise<EmailResult[]>;
}

interface SendEmailOptions {
  to: string | string[];
  subject: string;
  template: string;
  data: Record<string, unknown>;
  replyTo?: string;
  tags?: string[];
}

// Resend implementation
class ResendEmailService implements EmailService {
  private client: Resend;

  constructor(apiKey: string) {
    this.client = new Resend(apiKey);
  }

  async send(options: SendEmailOptions): Promise<EmailResult> {
    const html = await renderTemplate(options.template, options.data);

    const result = await this.client.emails.send({
      from: 'Your App <[email protected]>',
      to: Array.isArray(options.to) ? options.to : [options.to],
      subject: options.subject,
      html,
      reply_to: options.replyTo,
      tags: options.tags?.map(t => ({ name: t, value: 'true' }))
    });

    return {
      id: result.id,
      success: true
    };
  }

  async sendBatch(emails: SendEmailOptions[]): Promise<EmailResult[]> {
    return Promise.all(emails.map(e => this.send(e)));
  }
}

// Usage
const emailService = new ResendEmailService(process.env.RESEND_API_KEY);

await emailService.send({
  to: '[email protected]',
  subject: 'Welcome to Our App',
  template: 'welcome',
  data: { userName: 'John', appName: 'MyApp' }
});