import { Lettr } from 'lettr';

const lettr = new Lettr(process.env.LETTR_API_KEY);

await lettr.emails.send({
  from: 'hello@example.com',
  to: ['user@example.com'],
  subject: 'Hello World',
  html: '<p>Welcome to Lettr!</p>'
});

import fs from 'fs';

const pdfBuffer = fs.readFileSync('invoice.pdf');

await lettr.emails.send({
  from: 'billing@example.com',
  to: ['customer@example.com'],
  subject: 'Your Invoice',
  html: '<p>Please find your invoice attached.</p>',
  attachments: [{
    filename: 'invoice.pdf',
    content: pdfBuffer.toString('base64'),
    contentType: 'application/pdf'
  }]
});

await lettr.emails.send({
  from: 'newsletter@example.com',
  to: ['user1@example.com', 'user2@example.com'],
  subject: 'Weekly Update',
  html: '<p>Here is your weekly update...</p>',
  recipientVariables: {
    'user1@example.com': { name: 'Alice' },
    'user2@example.com': { name: 'Bob' }
  }
});

// app/api/contact/route.ts
import { NextResponse } from 'next/server';
import { Lettr } from 'lettr';

const lettr = new Lettr(process.env.LETTR_API_KEY!);

export async function POST(request: Request) {
  const { name, email, message } = await request.json();

  await lettr.emails.send({
    from: 'contact@example.com',
    to: ['team@example.com'],
    subject: `Contact from ${name}`,
    html: `
      <h2>New Contact Message</h2>
      <p><strong>From:</strong> ${name} (${email})</p>
      <p><strong>Message:</strong></p>
      <p>${message}</p>
    `
  });

  return NextResponse.json({ success: true });
}

import express from 'express';
import { Lettr } from 'lettr';

const lettr = new Lettr(process.env.LETTR_API_KEY);

const emailMiddleware = (template) => async (req, res, next) => {
  req.sendEmail = async (to, variables) => {
    return lettr.emails.send({
      from: 'app@example.com',
      to: [to],
      templateId: template,
      variables
    });
  };
  next();
};

app.post('/signup', emailMiddleware('welcome'), async (req, res) => {
  const user = await createUser(req.body);
  await req.sendEmail(user.email, { name: user.name });
  res.json({ success: true });
});

<?php

namespace App\Http\Controllers;

use Lettr\Facades\Lettr;

class ContactController extends Controller
{
    public function send(Request $request)
    {
        $validated = $request->validate([
            'name' => 'required|string',
            'email' => 'required|email',
            'message' => 'required|string'
        ]);

        Lettr::emails()->send([
            'from' => 'contact@example.com',
            'to' => ['team@example.com'],
            'subject' => "Contact from {$validated['name']}",
            'html' => view('emails.contact', $validated)->render()
        ]);

        return response()->json(['success' => true]);
    }
}

import express from 'express';
import { verifyWebhook } from 'lettr';

const app = express();

app.post('/webhooks/lettr', 
  express.raw({ type: 'application/json' }), 
  async (req, res) => {
    try {
      const event = verifyWebhook(
        req.body,
        req.headers['lettr-signature'],
        process.env.LETTR_WEBHOOK_SECRET
      );

      switch (event.type) {
        case 'email.delivered':
          await logDelivery(event.data);
          break;
        case 'email.bounced':
          await handleBounce(event.data);
          break;
        case 'email.opened':
          await trackOpen(event.data);
          break;
      }

      res.sendStatus(200);
    } catch (err) {
      console.error('Webhook error:', err);
      res.sendStatus(400);
    }
  }
);