Update to Twilio Developer Kit

{
  "name": "twilio-sendgrid-email-settings",
  "description": "Configure SendGrid dynamic templates (Handlebars), tracking settings (opens, clicks, subscriptions), link branding for custom tracking domains, and content types (HTML, plain text, AMP). Use when customizing SendGrid email content, tracking behavior, or branded links. Requires a SendGrid API key (SG.-prefix) — not applicable to the Twilio Email API (comms.twilio.com).",
  "included_files": [
    {
      "relative_path": "agents/openai.yaml",
      "size_in_bytes": 241
    }
  ],
  "skill_md_contents": "---\nname: twilio-sendgrid-email-settings\ndescription: >\n  Configure SendGrid dynamic templates (Handlebars), tracking settings\n  (opens, clicks, subscriptions), link branding for custom tracking\n  domains, and content types (HTML, plain text, AMP). Use when customizing\n  SendGrid email content, tracking behavior, or branded links. Requires a\n  SendGrid API key (SG.-prefix) — not applicable to the Twilio Email API\n  (comms.twilio.com).\n---\n\n## Overview\n\nSendGrid email settings control how your messages are constructed, personalized, and tracked. Most configuration happens in the SendGrid Console, but templates and tracking can also be managed via API.\n\n---\n\n## Dynamic Templates\n\nTemplates use Handlebars syntax and are managed in Console > Email API > Dynamic Templates. Template IDs start with `d-`.\n\n**Supported Handlebars helpers:**\n\n| Helper | Use | Example |\n|--------|-----|---------|\n| `if` / `unless` | Conditional | `{{#if premium}}Welcome back!{{/if}}` |\n| `each` | Iteration | `{{#each items}}{{this.name}}{{/each}}` |\n| `equals` / `notEquals` | Comparison | `{{#equals status \"active\"}}...{{/equals}}` |\n| `and` / `or` | Boolean logic | `{{#and premium verified}}...{{/and}}` |\n| `greaterThan` / `lessThan` | Numeric | `{{#greaterThan count 5}}...{{/greaterThan}}` |\n| `length` | Array/string | `{{length items}}` |\n| `formatDate` | Date format | `{{formatDate date \"MM/DD/YYYY\"}}` |\n| `insert` | Module insert | `{{insert \"module_name\"}}` |\n\n**NOT supported:** Custom helpers, inline partials, `lookup`, `log`, `with`, `blockHelperMissing`. SendGrid implements a subset of Handlebars.js.\n\n### Template Versions\n\n- **Dynamic templates** (IDs starting with `d-`): Support Handlebars\n- **Legacy transactional templates**: Use `-substitution-` syntax — not interchangeable with Handlebars\n\n---\n\n## Tracking Settings\n\n| Setting | What it does | Caveat |\n|---------|-------------|--------|\n| **Open tracking** | Inserts a tracking pixel | Unreliable: Apple Mail Privacy Protection inflates opens; image-blocking clients produce false negatives |\n| **Click tracking** | Rewrites URLs through SendGrid's redirect | Can trigger spam filters on some domains |\n| **Subscription tracking** | Adds unsubscribe footer | Required for CAN-SPAM compliance |\n| **Google Analytics** | Adds UTM parameters | Only for marketing campaigns |\n\nConfigure per-message or account-wide in Console > Settings > Tracking.\n\n---\n\n## Link Branding (Custom Tracking Domains)\n\nBy default, click-tracked links route through `url####.ct.sendgrid.net`. Link Branding lets you use your own domain (e.g., `links.yourdomain.com`) instead, which improves deliverability and builds trust.\n\n**Setup:** Console > Settings > Sender Authentication > Link Branding\n\nRequires a CNAME DNS record pointing your subdomain to `sendgrid.net`. Validate via API: `GET /v3/whitelabel/links/{id}/validate`\n\n---\n\n## Content Type Priority\n\nWhen sending multiple content types, email clients display in this priority:\n\n1. `text/x-amp-html` (AMP — only in supporting clients, requires sender registration)\n2. `text/html` (standard — most clients)\n3. `text/plain` (fallback)\n\nAlways include at least `text/plain` and `text/html`.\n\n---\n\n## CANNOT\n\n- **Cannot use custom Handlebars helpers** — Only the built-in set listed above.\n- **Cannot guarantee open tracking accuracy** — Pixel-based tracking is fundamentally unreliable. Do not use for business-critical logic.\n- **Personalizations `subject` is a plain string override** — It bypasses the template subject. To use dynamic subjects, set Handlebars variables (e.g., `{{{subject}}}`) in the Dynamic Template's subject field and pass values via `dynamic_template_data`.\n- **Undefined template variables are silent** — Missing keys in `dynamic_template_data` render as empty strings with no error.\n\n---\n\n## Next Steps\n\n- **Send email:** `twilio-sendgrid-email-send`\n- **Delivery tracking:** `twilio-sendgrid-webhooks`\n- **Manage bounces/unsubscribes:** `twilio-sendgrid-suppressions`\n"
}