Imported from francescobulychov/agentset_backup (agentset/.agents/skills/react-email/SKILL.md). Install upstream with npx skills add francescobulychov/agentset_backup --skill react-email. Copyright stays with the author.

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

New Project

Scaffold a new React Email project:

npx create-email@latest
cd react-email-starter
npm install
npm run dev

This creates a react-email-starter folder with sample templates. Also works with yarn, pnpm, or bun.

Existing Project

Add React Email to an existing codebase:

Install dependencies:

npm install @react-email/components
npm install react-email @react-email/preview-server -D

Create an emails directory:

mkdir emails

Add a preview script to package.json:

{
  "scripts": {
    "email:dev": "email dev"
  }
}

Start the preview server:

npm run email:dev

The --dir flag specifies where email templates are stored. Adjust the path to match your project structure (e.g., src/emails, app/emails).

Brand Setup (Required First Step)

Before creating any email template, gather brand information from the user. This ensures visual consistency across all emails.

Required Brand Information

Ask the user for:

Brand colors
- Primary color (main brand color for buttons, links, accents)
- Secondary color (supporting color for backgrounds, borders)
- Text color (default: #1a1a1a for light mode)
- Background color (default: #f4f4f5 for light mode)
Logo
- Logo image URL (must be absolute URL, PNG or JPEG)
- Logo dimensions or aspect ratio preference
- Logo placement preference (centered, left-aligned)
- Ask user for file and path of the local file if the logo is not a publicly accessible URL.
Typography (optional)
- Preferred font family (default: system fonts)
- Custom web font URL if applicable
Style preferences (optional)
- Modern/minimal vs. classic/traditional
- Rounded corners vs. sharp edges
- Spacing density (compact vs. spacious)
- Never add emojis unless the user explicitly requests them.

Brand Configuration Pattern

Once gathered, define a reusable Tailwind configuration. Using satisfies TailwindConfig provides intellisense support for all configuration options:

// emails/tailwind.config.ts
import { pixelBasedPreset, type TailwindConfig } from '@react-email/components';

export default {
  presets: [pixelBasedPreset],
  theme: {
    extend: {
      colors: {
        brand: {
          primary: '#007bff',      // User's primary brand color
          secondary: '#6c757d',    // User's secondary color
        },
      },
    },
  },
} satisfies TailwindConfig;

// For non-Tailwind brand assets (optional)
export const brandAssets = {
  logo: {
    src: 'https://example.com/logo.png',  // User's logo URL
    alt: 'Company Name',
    width: 120,
  },
};

Using Tailwind Config in Templates

import * as React from "react";
import tailwindConfig, { brandAssets } from './tailwind.config';
import { Tailwind, Img } from '@react-email/components';

<Tailwind config={tailwindConfig}>
  <Body className="bg-gray-100 font-sans">
    <Container className="max-w-xl mx-auto bg-white p-6">
      <Img
        src={brandAssets.logo.src}
        alt={brandAssets.logo.alt}
        width={brandAssets.logo.width}
        className="mx-auto mb-6"
      />
      <Button className="bg-brand-primary text-white rounded px-5 py-3">
        Call to Action
      </Button>
    </Container>
  </Body>
</Tailwind>

Asset Locations

Direct users to place brand assets in appropriate locations:

Logo and images: Host on a CDN or public URL. For local development, place in emails/static/.
Custom fonts: Use the Font component with a web font URL (Google Fonts, Adobe Fonts, or self-hosted).

Example prompt for gathering brand info:

"Before I create your email template, I need some brand information to ensure consistency. Could you provide:

Your primary brand color (hex code, e.g., #007bff)

Your logo URL (must be a publicly accessible PNG or JPEG)

Any secondary colors you'd like to use

Style preference (modern/minimal or classic/traditional)"

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 * as React from "react";
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

Brand-First Workflow

Always gather brand information before creating the first email template. Do not skip this step.
If the user requests an email without providing brand details, ask for them first using the prompt in the Brand Setup section.
If a tailwind.config.ts file exists in the emails directory, use it for all new templates.
When creating multiple emails, ensure all templates import and use the same brand configuration.
If the user provides new brand assets or colors mid-project, update tailwind.config.ts and offer to update existing templates.

General 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

Use the Tailwind component with pixelBasedPreset for styling (email clients don't support rem units). If not using Tailwind, use inline styles.

Critical limitations (email clients don't support these):

No SVG/WEBP images - use PNG/JPEG only
No flexbox/grid - use Row/Column components or tables
No media queries (sm:, md:, etc.) or theme selectors (dark:, light:)
Always specify border style (border-solid, etc.)

Structure rules:

Place <Head /> inside <Tailwind> when using Tailwind
Only include props in PreviewProps that the component uses

See references/STYLING.md for typography, layout defaults, button styling, dark mode, and detailed guidelines.

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 * as React from "react";
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 * as React from "react";
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

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.
Keep it responsive - Max-width around 600px, test on mobile devices.
Use absolute image URLs - Host on reliable CDN, always include alt text.
Provide plain text version - Required for accessibility and some email clients. The render function will generate this if you pass the plainText option.
Keep file size under 102KB - Gmail clips larger emails.
Add proper TypeScript types - Define interfaces for all email props.
Include preview props - Add .PreviewProps to components for development testing.
Handle errors - Always check for errors when sending emails.

Common Patterns

See references/PATTERNS.md for complete examples including:

Password reset emails
Order confirmations with product lists
Notification emails with code blocks
Multi-column layouts
Email templates with custom fonts

Additional Resources

React Email Documentation
React Email GitHub
Resend Documentation
Email Client CSS Support
Component Reference: references/COMPONENTS.md
Styling Guide: references/STYLING.md
Internationalization Guide: references/I18N.md
Common Patterns: references/PATTERNS.md

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