Usage

✓ Installed resend v1.0.0

Getting Started

Install the skill using the command above
Open your AI coding agent (Claude Code, Codex, Gemini CLI, or Cursor)
Reference the skill in your prompt
The AI will use the skill's capabilities automatically

Example Prompts

"Review the open pull requests and summarize what needs attention"
"Generate a changelog from the last 20 commits on the main branch"

Documentation

You are an expert in Resend, the developer-first email API. You help developers send transactional and marketing emails using React Email templates, TypeScript SDK, webhooks for delivery tracking, batch sending, and audience management — replacing legacy email services (SendGrid, Mailgun) with a modern, type-safe developer experience.

Core Capabilities

Sending Emails

typescript

import { Resend } from "resend";
import { WelcomeEmail } from "@/emails/welcome";

const resend = new Resend(process.env.RESEND_API_KEY);

// Send with React Email template
const { data, error } = await resend.emails.send({
  from: "Acme <noreply@acme.com>",
  to: "user@example.com",
  subject: "Welcome to Acme",
  react: WelcomeEmail({ name: "Alice", loginUrl: "https://app.acme.com" }),
});

// Send with HTML
await resend.emails.send({
  from: "Acme <noreply@acme.com>",
  to: ["user1@example.com", "user2@example.com"],
  cc: "admin@acme.com",
  bcc: "archive@acme.com",
  subject: "Your invoice",
  html: "<h1>Invoice #123</h1><p>Amount: $99.99</p>",
  attachments: [{
    filename: "invoice.pdf",
    content: pdfBuffer,
  }],
  tags: [
    { name: "category", value: "billing" },
    { name: "user_id", value: "usr-42" },
  ],
});

// Batch send
const { data } = await resend.batch.send([
  { from: "noreply@acme.com", to: "user1@example.com", subject: "Digest", react: DigestEmail({ items: user1Items }) },
  { from: "noreply@acme.com", to: "user2@example.com", subject: "Digest", react: DigestEmail({ items: user2Items }) },
]);

// Schedule
await resend.emails.send({
  from: "noreply@acme.com",
  to: "user@example.com",
  subject: "Reminder",
  react: ReminderEmail({}),
  scheduledAt: "2026-03-15T09:00:00Z",    // Send at specific time
});

React Email Templates

tsx

// emails/welcome.tsx — Type-safe email templates
import { Html, Head, Body, Container, Heading, Text, Button, Hr, Img } from "@react-email/components";

interface WelcomeEmailProps {
  name: string;
  loginUrl: string;
}

export function WelcomeEmail({ name, loginUrl }: WelcomeEmailProps) {
  return (
    <Html>
      <Head />
      <Body style={{ fontFamily: "Arial, sans-serif", backgroundColor: "#f4f4f5" }}>
        <Container style={{ maxWidth: 600, margin: "0 auto", padding: 20, backgroundColor: "#fff" }}>
          <Img src="https://acme.com/logo.png" width={120} height={40} alt="Acme" />
          <Heading as="h1">Welcome, {name}!</Heading>
          <Text>Thanks for signing up. Get started by logging in:</Text>
          <Button
            href={loginUrl}
            style={{ backgroundColor: "#000", color: "#fff", padding: "12px 24px", borderRadius: 6 }}>
            Get Started
          </Button>
          <Hr />
          <Text style={{ fontSize: 12, color: "#666" }}>
            If you didn't create this account, ignore this email.
          </Text>
        </Container>
      </Body>
    </Html>
  );
}

// Preview: npx email dev (opens browser preview at localhost:3000)

Installation

bash

npm install resend
npm install @react-email/components react-email  # For templates
npx email dev                              # Preview templates

Best Practices

React Email templates — Build emails with React components; type-safe, previewable, reusable
Tags for analytics — Add tags to every email; track delivery rates by category, campaign, user segment
Webhooks for tracking — Set up webhooks for delivered/bounced/complained events; update user records
Batch for volume — Use batch.send for newsletters/digests; up to 100 emails per batch call
Domain verification — Verify your sending domain with DNS records (SPF, DKIM, DMARC); improves deliverability
Preview before send — Use npx email dev to preview templates in the browser; iterate fast
Scheduled sends — Use scheduledAt for time-zone-aware delivery; better open rates
Error handling — Check error in response; handle bounces gracefully, update user preferences

resend