@upyo/resend

Resend transport for the Upyo email library.

Features

• Single and batch email sending via Resend's HTTP API
• Automatic idempotency for reliable delivery
• Smart batch optimization: uses batch API when possible
• Cross-runtime compatibility (Node.js, Deno, Bun, edge functions)
• Rich content support: HTML emails, attachments, custom headers
• Retry logic with exponential backoff
• Type-safe configuration with sensible defaults
• Comprehensive error handling

Installation

npm  add       @upyo/core @upyo/resend
pnpm add       @upyo/core @upyo/resend
yarn add       @upyo/core @upyo/resend
deno add --jsr @upyo/core @upyo/resend
bun  add       @upyo/core @upyo/resend

Usage

import { createMessage } from "@upyo/core";
import { ResendTransport } from "@upyo/resend";
import process from "node:process";

const message = createMessage({
  from: "sender@example.com",
  to: "recipient@example.net",
  subject: "Hello from Upyo!",
  content: { text: "This is a test email." },
});

const transport = new ResendTransport({
  apiKey: process.env.RESEND_API_KEY!,
});

const receipt = await transport.send(message);
if (receipt.successful) {
  console.log("Message sent with ID:", receipt.messageId);
} else {
  console.error("Send failed:", receipt.errorMessages.join(", "));
}

Sending Multiple Emails

const messages = [message1, message2, message3];

for await (const receipt of transport.sendMany(messages)) {
  if (receipt.successful) {
    console.log(`Email sent with ID: ${receipt.messageId}`);
  } else {
    console.error(`Email failed: ${receipt.errorMessages.join(", ")}`);
  }
}

Configuration

See the Resend docs for more information about configuration options.

Available Options

• apiKey: Your Resend API key
• baseUrl: Resend API base URL (default: https://api.resend.com)
• timeout: Request timeout in milliseconds (default: 30000)
• retries: Number of retry attempts (default: 3)
• validateSsl: Whether to validate SSL certificates (default: true)
• headers: Additional HTTP headers