Resend Skills

Resend Skills provides a collection of specialized capabilities for AI agents. Skills are categorized by whether they are authored directly in this repository or synced from external sources.

Note: Do not edit skills marked as "Synced from" in this repository, as changes will be overwritten. Edit those in their original source repositories.

Resend templates use triple mustache syntax for variable substitution in both HTML and the email subject.

Important Constraints:

• Syntax: Use {{{VARIABLE_NAME}}}. Double braces {{VAR}} will not render.
• No Logic: Templates only support plain substitution. They do not support Handlebars control flow like {{#each}} or {{#if}}. For dynamic lists, pre-render the HTML server-side and pass it as a single string variable.
• Casing: Variable key casing is arbitrary but must be consistent between the template definition and the variables object in your send call.
• Reserved Names: You cannot use the following as custom variable keys: FIRST_NAME, LAST_NAME, EMAIL, UNSUBSCRIBE_URL, RESEND_UNSUBSCRIBE_URL, contact, or this. Use prefixes like USER_FIRST_NAME instead.

<!-- ✅ Correct -->
<p>Hi {{{CUSTOMER_NAME}}}, your order #{{{ORDER_ID}}} has shipped!</p>

<!-- ❌ Wrong (will not render) -->
<p>Hi {{CUSTOMER_NAME}}</p>

Email compliance requirements vary significantly by jurisdiction. When sending internationally, it is a best practice to follow the most restrictive requirements (typically GDPR) to ensure global compliance.

CAN-SPAM (United States)

• Requirements: Accurate header info (From, To, Reply-To), non-deceptive subject lines, physical mailing address in every email, and a clear opt-out mechanism.
• Opt-out timing: Must honor opt-outs within 10 business days.
• Transactional emails: Can be sent without opt-in if they are related to a transaction and not promotional.

GDPR (European Union)

• Requirements: Explicit opt-in consent (no pre-checked boxes) that is freely given, specific, and informed. Users must be able to withdraw consent as easily as they gave it.
• Rights: Users have the right to access data and the "right to be forgotten" (deletion).
• Transactional emails: Can be sent based on contract fulfillment or legitimate interest.

CASL (Canada)

• Consent types:
  • Express consent: Explicit opt-in (recommended).
  • Implied consent: Based on an existing business relationship (valid for 2 years) or an inquiry (valid for 6 months).
• Requirements: Clear sender identification (valid for 60 days after send) and a functional unsubscribe mechanism (valid for 60 days after send).
• Opt-out timing: Process unsubscribe no later than 10 business days.
• Record keeping: Keep consent records for 3 years after expiration.

Resend Templates are reusable email structures stored on the Resend platform. They allow you to define HTML and variables once and reference them by a template ID or a human-readable alias during email sends.

Template Lifecycle:

1. Create (Draft): When you create a template, it starts in a Draft state. Drafts cannot be sent.
2. Publish: You must call .publish() to move a template to the Published state. Only Published templates can be used in resend.emails.send() calls.
3. Edit: Editing a published template creates a new draft. The existing published version remains active and continues to send until you explicitly publish the new version.

When to use templates vs. inline HTML:

• Use Templates when: You reuse the same structure across many sends, want non-engineers to edit copy via the dashboard, or need version history.
• Use inline html when: The structure changes per send, you need more than 50 dynamic variables, or you require complex logic like loops/conditionals (which templates do not support).

// Lifecycle: Create -> Publish -> Send
const { data } = await resend.templates.create({
  name: 'Welcome',
  html: '<p>Hi {{{NAME}}}</p>',
}).publish();