Imported from MinhDuyDEV/pi-harness (.pi/skills/resend/SKILL.md). Install upstream with npx skills add MinhDuyDEV/pi-harness --skill resend. Copyright stays with the author.

Resend (Email)

Iron Laws

When to Use

Transactional sends (magic link, verification, password reset, receipts); newsletters and bulk notifications; inbound email handling; building or previewing email templates.

Setup

npm i resend react-email @react-email/components
export RESEND_API_KEY="re_..."

Method

1. Model each email as a React Email component in emails/; preview locally with email dev before sending anything.
2. Send with the typed SDK, passing the component to the react prop.
3. Use POST /emails/batch (max 100) for multiple distinct emails; Audiences + contacts API for managed lists.
4. For replies/inbound: configure the receiving domain (MX record or .resend.app), subscribe a webhook to email.received, then retrieve content via the API — the webhook payload does not contain the body.

References

• See references/send-email.md for single vs batch endpoints, scheduling, attachments, and idempotency.
• See references/react-email.md for template components, client compatibility, and the preview workflow.
• See references/receive-email.md for inbound domains, webhook events, and content retrieval.

Red Flags

String-concatenated HTML instead of React Email; API key committed to code; polling or IMAP for inbound; treating the inbound webhook payload as if it contained the full body; test emails sent to real addresses; bulk sends without an unsubscribe link; missing replyTo; no error or rate-limit handling around send calls; "templates later" (templates first).