resend

Install the resend SDK, initialize it with your RESEND_API_KEY, and call resend.emails.send with from, to, subject, and html parameters. Always pass an idempotency key like welcome-email/user-123 to prevent duplicate sends on retries.

Use resend.webhooks.verify with the raw request body, the svix-id, svix-timestamp, and svix-signature headers, and your RESEND_WEBHOOK_SECRET. Never parse the body as JSON before verification, since that breaks the signature.

Resend webhook payloads contain metadata only, such as sender, subject, and attachment IDs. Call resend.emails.receiving.get with the email_id from the event to retrieve the actual HTML and text body.

No, the Resend batch endpoint does not support attachments or scheduled sends. Use individual single-email sends when you need attachments, scheduling, or per-email customization beyond the batch limits.

The default [email protected] address is a sandbox that only delivers to your own Resend account email. To send to real recipients, verify your own domain by adding the DNS records from resend.domains.create and confirming verification.

Resend templates use triple-mustache syntax like {{{CUSTOMER_NAME}}}, with optional fallbacks via {{{FIRST_NAME|there}}}. Double braces do not render, variable names are case-sensitive, and templates must be published before sending.