Resend

Resend is a transactional email API. Domains must be verified before sending. Emails are sent via API; audiences and broadcasts support marketing use cases. Rate limit: 120 requests/min (429 on exceed).

Data Model

• Domains must be verified (DNS records) before sending. List with resend_list_domains. Sending from unverified domains fails.
• Emails are sent messages. List with resend_list_emails. Fetch single email with fetch tool using resource id resend:email:{email_id}.
• Audiences are contact lists. List with resend_list_audiences; contacts within an audience via resend_list_contacts(audience_id).
• Broadcasts are bulk sends. List with resend_list_broadcasts.
• API Keys can be listed (resend_list_api_keys). Use one key per environment.

Gotchas

• From domain must be verified: Sending from @yourdomain.com requires yourdomain.com to be verified in Resend.
• Rate limit 429: 120 req/min. Use queue for bulk; space requests.
• fetch resource id: For emails, use resend:email:{email_id} not raw email_id.
• Audience required for contacts: resend_list_contacts requires audience_id from resend_list_audiences.