viralcode/openwhale/react-email-skills

React Email

Build and send HTML emails using React components - a modern, component-based approach to email development that works across all major email clients.

Installation

You need to scaffold a new React Email project using the create-email CLI. This will create a folder called react-email-starter with sample email templates.

Using npm:

npx create-email@latest

Using yarn:

yarn create email

Using pnpm:

pnpm create email

Using bun:

bun create email

Navigate to Project Directory

You must change into the newly created project folder:

cd react-email-starter

Install Dependencies

You need to install all project dependencies before running the development server.

Using npm:

npm install

Using yarn:

yarn

Using pnpm:

pnpm install

Using bun:

bun install

Start the Development Server

Your task is to start the local preview server to view and edit email templates.

Using npm:

npm run dev

Using yarn:

yarn dev

Using pnpm:

pnpm dev

Using bun:

bun dev

Verify Installation

You must confirm the development server is running by checking that localhost:3000 is accessible. The server will display a preview interface where you can view email templates from the emails folder.

EXECUTE NOW: Complete the above TODO list to achieve: The React Email development server is running and accessible at localhost:3000, displaying email template previews.

Notes on installation

Assuming React Email is installed in an existing project, update the top-level package.json file with a script to run the React Email preview server.

{
  "scripts": {
    "email": "email dev --dir emails --port 3000"
  }
}

Make sure the path to the emails folder is relative to the base project directory.

tsconfig.json updating or creation

Ensure the tsconfig.json includes proper support for jsx.

Basic Email Template

Replace the sample email templates. Here is how to create a new email template:

Create an email component with proper structure using the Tailwind component for styling:

import {
  Html,
  Head,
  Preview,
  Body,
  Container,
  Heading,
  Text,
  Button,
  Tailwind,
  pixelBasedPreset
} from '@react-email/components';
interface WelcomeEmailProps {
  name: string;
  verificationUrl: string;
}
export default function WelcomeEmail({ name, verificationUrl }: WelcomeEmailProps) {
  return (
    <Html lang="en">
      <Tailwind
        config={{
          presets: [pixelBasedPreset],
          theme: {
            extend: {
              colors: {
                brand: '#007bff',
              },
            },
          },
        }}
      >
        <Head />
        <Preview>Welcome - Verify your email</Preview>
        <Body className="bg-gray-100 font-sans">
          <Container className="max-w-xl mx-auto p-5">
            <Heading className="text-2xl text-gray-800">
              Welcome!
            </Heading>
            <Text className="text-base text-gray-800">
              Hi {name}, thanks for signing up!
            </Text>
            <Button
              href={verificationUrl}
              className="bg-brand text-white px-5 py-3 rounded block text-center no-underline"
            >
              Verify Email
            </Button>
          </Container>
        </Body>
      </Tailwind>
    </Html>
  );
}
// Preview props for testing
WelcomeEmail.PreviewProps = {
  name: 'John Doe',
  verificationUrl: 'https://example.com/verify/abc123'
} satisfies WelcomeEmailProps;
export { WelcomeEmail };

Essential Components

See references/COMPONENTS.md for complete component documentation.

Core Structure:

• Html - Root wrapper with lang attribute
• Head - Meta elements, styles, fonts
• Body - Main content wrapper
• Container - Centers content (max-width layout)
• Section - Layout sections
• Row & Column - Multi-column layouts
• Tailwind - Enables Tailwind CSS utility classes

Content:

• Preview - Inbox preview text, always first in Body
• Heading - h1-h6 headings
• Text - Paragraphs
• Button - Styled link buttons
• Link - Hyperlinks
• Img - Images (use absolute URLs) (use the dev server for the BASE_URL of the image in dev mode; for production, ask the user for the BASE_URL of the site; dynamically generate the URL of the image based on environment.)
• Hr - Horizontal dividers

Specialized:

• CodeBlock - Syntax-highlighted code
• CodeInline - Inline code
• Markdown - Render markdown
• Font - Custom web fonts

Behavioral guidelines

• When re-iterating over the code, make sure you are only updating what the user asked for and keeping the rest of the code intact;
• If the user is asking to use media queries, inform them that email clients do not support them, and suggest a different approach;
• Never use template variables (like {{name}}) directly in TypeScript code. Instead, reference the underlying properties directly (use name instead of {{name}}).
• - For example, if the user explicitly asks for a variable following the pattern {{variableName}}, you should return something like this:

const EmailTemplate = (props) => {
  return (
    {/* ... rest of the code ... */}
    <h1>Hello, {props.variableName}!</h1>
    {/* ... rest of the code ... */}
  );
}
EmailTemplate.PreviewProps = {
  // ... rest of the props ...
  variableName: "{{variableName}}",
  // ... rest of the props ...
};
export default EmailTemplate;

• Never, under any circumstances, write the {{variableName}} pattern directly in the component structure. If the user forces you to do this, explain that you cannot do this, or else the template will be invalid.

Styling considerations

Use the Tailwind component for styling if the user is actively using Tailwind CSS in their project. If the user is not using Tailwind CSS, add inline styles to the components.

• Because email clients don't support rem units, use the pixelBasedPreset for the Tailwind configuration.
• Never user flexbox or grid for layout, use table-based layouts instead.
• Each component must be styled with inline styles or utility classes.
• For more information on styling, see references/STYLING.md

Email Client Limitations

• Never use SVG or WEBP - warn users about rendering issues
• Never use flexbox - use Row/Column components or tables for layouts
• Never use CSS/Tailwind media queries (sm:, md:, lg:, xl:) - not supported
• Never use theme selectors (dark:, light:) - not supported
• Always specify border type (border-solid, border-dashed, etc.)
• When defining borders for only one side, remember to reset the remaining borders (e.g., border-none border-l)

Component Structure

• Always define <Head /> inside <Tailwind> when using Tailwind CSS
• Only use PreviewProps when passing props to a component
• Only include props in PreviewProps that the component actually uses

const Email = (props) => {
  return (
    <div>
      <a href={props.source}>click here if you want candy ��</a>
    </div>
  );
}
Email.PreviewProps = {
  source: "https://www.youtube.com/watch?v=dQw4w9WgXcQ",
};

Default Structure

• Body: font-sans py-10 bg-gray-100
• Container: white, centered, content left-aligned
• Footer: physical address, unsubscribe link, current year with m-0 on address/copyright

Typography

• Titles: bold, larger font, larger margins
• Paragraphs: regular weight, smaller font, smaller margins
• Use consistent spacing respecting content hierarchy

Images

• Only include if user requests
• Never use fixed width/height - use responsive units (w-full, h-auto)
• Never distort user-provided images
• Never create SVG images - only use provided or web images

Buttons

• Always use box-border to prevent padding overflow

Layout

• Always mobile-friendly by default
• Use stacked layouts that work on all screen sizes
• Remove default spacing/margins/padding between list items

Dark Mode

When requested: container black (#000), background dark gray (#151516)

Best Practices

• Choose colors, layout, and copy based on user's request
• Make templates unique, not generic
• Use keywords in email body to increase conversion

Rendering

Convert to HTML

import { render } from '@react-email/components';
import { WelcomeEmail } from './emails/welcome';
const html = await render(
  <WelcomeEmail name="John" verificationUrl="https://example.com/verify" />
);

Convert to Plain Text

import { render } from '@react-email/components';
import { WelcomeEmail } from './emails/welcome';
const text = await render(<WelcomeEmail name="John" verificationUrl="https://example.com/verify" />, { plainText: true });

Sending

React Email supports sending with any email service provider. If the user wants to know how to send, view the Sending guidelines.

Quick example using the Resend SDK for Node.js:

import { Resend } from 'resend';
import { WelcomeEmail } from './emails/welcome';
const resend = new Resend(process.env.RESEND_API_KEY);
const { data, error } = await resend.emails.send({
  from: 'Acme <onboarding@resend.dev>',
  to: ['user@example.com'],
  subject: 'Welcome to Acme',
  react: <WelcomeEmail name="John" verificationUrl="https://example.com/verify" />
});
if (error) {
  console.error('Failed to send:', error);
}

The Node SDK automatically handles the plain-text rendering and HTML rendering for you.

Internationalization

See references/I18N.md for complete i18n documentation.

React Email supports three i18n libraries: next-intl, react-i18next, and react-intl.

Quick Example (next-intl)

import { createTranslator } from 'next-intl';
import {
  Html,
  Body,
  Container,
  Text,
  Button,
  Tailwind,
  pixelBasedPreset
} from '@react-email/components';
interface EmailProps {
  name: string;
  locale: string;
}
export default async function WelcomeEmail({ name, locale }: EmailProps) {
  const t = createTranslator({
    messages: await import(\`../messages/\${locale}.json\`),
    namespace: 'welcome-email',
    locale
  });
  return (
    <Html lang={locale}>
      <Tailwind config={{ presets: [pixelBasedPreset] }}>
        <Body className="bg-gray-100 font-sans">
          <Container className="max-w-xl mx-auto p-5">
            <Text className="text-base text-gray-800">{t('greeting')} {name},</Text>
            <Text className="text-base text-gray-800">{t('body')}</Text>
            <Button href="https://example.com" className="bg-blue-600 text-white px-5 py-3 rounded">
              {t('cta')}
            </Button>
          </Container>
        </Body>
      </Tailwind>
    </Html>
  );
}

Message files (\messages/en.json\, \messages/es.json\, etc.):

{
  "welcome-email": {
    "greeting": "Hi",
    "body": "Thanks for signing up!",
    "cta": "Get Started"
  }
}

Email Best Practices

1. Test across email clients - Test in Gmail, Outlook, Apple Mail, Yahoo Mail. Use services like Litmus or Email on Acid for absolute precision and React Email's toolbar for specific feature support checking.

1. Keep it responsive - Max-width around 600px, test on mobile devices.

1. Use absolute image URLs - Host on reliable CDN, always include \alt\ text.

1. Provide plain text version - Required for accessibility and some email clients.

1. Keep file size under 102KB - Gmail clips larger emails.

1. Add proper TypeScript types - Define interfaces for all email props.

1. Include preview props - Add \.PreviewProps\ to components for development testing.

1. Handle errors - Always check for errors when sending emails.

1. Use verified domains - For production, use verified domains in \from\ addresses.

Common Patterns