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Serverless Quickstart

Learn how to use Lettr in serverless environments.

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Overview

Lettr is designed to work seamlessly in serverless environments. Our lightweight SDKs and fast API response times make it perfect for:
  • AWS Lambda
  • Cloudflare Workers
  • Vercel Functions
  • Netlify Functions
  • Google Cloud Functions

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Key Considerations

Our SDKs are optimized for minimal cold start impact. Connection pooling is handled automatically.
Lettr’s API typically responds within 100-300ms, well within most serverless timeout limits.
Always store your API key in environment variables, never in code.

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Quick Example

Here’s a simple serverless function that sends an email: 
export default async function handler(req, res) {
  const response = await fetch('https://api.lettr.dev/v1/emails', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.LETTR_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      from: 'you@example.com',
      to: ['recipient@example.com'],
      subject: 'Hello from Serverless',
      html: '<p>Sent from a serverless function!</p>'
    })
  });

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

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Next Steps

AWS Lambda

Deploy on AWS Lambda

Cloudflare Workers

Deploy on Cloudflare Workers

Vercel Functions

Deploy on Vercel Functions