# Email Templates for Newsletter Tiers

This directory contains HTML email templates for the four newsletter subscription tiers:

1. **research-updates.html** - Monthly research insights (scholarly audience)
2. **implementation-notes.html** - Bi-weekly implementation guidance (practitioners)
3. **governance-discussions.html** - Sporadic values/governance topics (stakeholders)
4. **project-updates.html** - Quarterly project milestones (general audience)

## Template Variables

All templates use Mustache-style {{variables}} for dynamic content:

- `{{name}}` - Subscriber name
- `{{unsubscribe_link}}` - Unsubscribe URL
- `{{preferences_link}}` - Preferences management URL
- `{{website_link}}` - https://agenticgovernance.digital
- `{{docs_link}}` - https://agenticgovernance.digital/docs.html
- `{{github_link}}` - https://github.com/AgenticGovernance/tractatus-framework
- Content-specific variables documented in each template

## Usage

Templates are loaded by the newsletter admin UI and processed with a template engine (e.g., Handlebars, Mustache) before sending via email service.

## Design Principles

- Inline CSS for email client compatibility
- Responsive design (mobile-friendly)
- Accessible (semantic HTML, sufficient contrast)
- Brand-consistent (blue gradient header, clean typography)
- Clear CTA buttons with good hit targets
- Unsubscribe link always visible in footer

## Template Usage

### Base Template (`base-template.html`)

The base template provides the outer HTML structure with header, footer, and styling. It uses these placeholders:

- `{{email_title}}` - Email subject (for <title> tag)
- `{{header_title}}` - Main header text (e.g., "Tractatus Research Updates")
- `{{header_subtitle}}` - Subtitle text (e.g., "Monthly insights from AI governance research")
- `{{name}}` - Subscriber name
- `{{content_body}}` - HTML content injected here
- `{{tier_name}}` - Newsletter tier name (for footer)
- `{{unsubscribe_link}}` - Unsubscribe URL
- `{{preferences_link}}` - Preferences management URL

### Content Modules

Content modules are HTML snippets that get injected into `{{content_body}}`. Example:
- `research-updates-content.html` - Research Updates tier content structure

### Implementation with Template Engine

```javascript
const Handlebars = require('handlebars');
const fs = require('fs');

// Load templates
const baseTemplate = fs.readFileSync('email-templates/base-template.html', 'utf8');
const contentModule = fs.readFileSync('email-templates/research-updates-content.html', 'utf8');

// Compile
const compiledContent = Handlebars.compile(contentModule);
const compiledBase = Handlebars.compile(baseTemplate);

// Render content
const renderedContent = compiledContent({
  highlight_1_title: "...",
  highlight_1_summary: "...",
  // ... all other variables
});

// Render final email
const finalEmail = compiledBase({
  email_title: "Tractatus Research Updates - November 2025",
  header_title: "Tractatus Research Updates",
  header_subtitle: "Monthly insights from AI governance research",
  name: subscriber.name || "there",
  content_body: renderedContent,
  tier_name: "Research Updates",
  unsubscribe_link: `https://agenticgovernance.digital/api/newsletter/unsubscribe?token=${subscriber.token}`,
  preferences_link: `https://agenticgovernance.digital/newsletter/preferences?token=${subscriber.token}`
});
```

### Plain Text Version

Always generate a plain-text version alongside HTML for accessibility and spam filtering:

```javascript
const htmlToText = require('html-to-text');
const plainText = htmlToText.convert(finalEmail, {
  wordwrap: 80,
  ignoreImages: true
});
```

### Testing

Test emails with [Litmus](https://www.litmus.com/) or [Email on Acid](https://www.emailonacid.com/) across:
- Gmail (desktop, mobile)
- Outlook (2016+, 365)
- Apple Mail (macOS, iOS)
- Yahoo Mail
- Thunderbird

### Sending

Use a transactional email service:
- **SendGrid**: https://sendgrid.com/
- **Mailgun**: https://www.mailgun.com/
- **AWS SES**: https://aws.amazon.com/ses/

Example with SendGrid:

```javascript
const sgMail = require('@sendgrid/mail');
sgMail.setApiKey(process.env.SENDGRID_API_KEY);

await sgMail.send({
  to: subscriber.email,
  from: 'research@agenticgovernance.digital',
  subject: 'Tractatus Research Updates - November 2025',
  html: finalEmail,
  text: plainText,
  trackingSettings: {
    clickTracking: { enable: true },
    openTracking: { enable: true }
  }
});
```