Cloudflare Workers

import { Lettr } from 'lettr';

export interface Env {
  LETTR_API_KEY: string;
  FROM_EMAIL?: string;
}

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    // Only allow POST requests
    if (request.method !== 'POST') {
      return new Response('Method not allowed', { status: 405 });
    }

    // Initialize Lettr client
    const lettr = new Lettr(env.LETTR_API_KEY);

    try {
      const body = await request.json() as {
        to: string | string[];
        subject: string;
        html?: string;
        text?: string;
      };

      const { to, subject, html, text } = body;

      // Validate required fields
      if (!to || !subject || (!html && !text)) {
        return Response.json(
          { error: 'Missing required fields: to, subject, and html or text' },
          { status: 400 }
        );
      }

      // Send email
      const result = await lettr.emails.send({
        from: env.FROM_EMAIL || 'noreply@yourdomain.com',
        to: Array.isArray(to) ? to : [to],
        subject,
        html,
        text,
      });

      console.log(`Email sent successfully. Request ID: ${result.request_id}`);

      return Response.json({
        success: true,
        requestId: result.request_id,
        accepted: result.accepted,
      });
    } catch (error: any) {
      console.error('Failed to send email:', error);

      return Response.json(
        { error: error.message || 'Failed to send email' },
        { status: error.status || 500 }
      );
    }
  },
};

name = "my-email-worker"
main = "src/index.ts"
compatibility_date = "2024-01-01"

# Non-sensitive environment variables
[vars]
FROM_EMAIL = "noreply@yourdomain.com"

# Secrets (set via wrangler secret put)
# LETTR_API_KEY = "set via CLI"