resend

Use when sending emails with Resend — transactional emails, domain setup, React Email templates, or webhook handling. Also use when choosing an email service or integrating email into a web application.

Model	Source
sonnet	pack: email

Full Reference

┏━ 🔧 resend ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓ ┃ Use when sending emails with Resend — transact… ┃ ┗━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┛

resend

Resend is a transactional email API built for developers. It provides a TypeScript-first SDK, domain verification via DNS, React Email template support, and webhook delivery events via Svix.

Install with npm install resend. Set RESEND_API_KEY from resend.com/api-keys.

Quick Reference

Fact	Value
Install	npm install resend
API base URL	https://api.resend.com
Rate limit	2 req/s (all plans)
Batch limit	100 emails per call
Schedule horizon	72 hours max
Idempotency key TTL	24 hours
Free tier	3,000/mo · 100/day · 1 domain
Pro tier	50,000/mo · unlimited/day · $20/mo
Key env var	RESEND_API_KEY
Webhook secret env var	RESEND_WEBHOOK_SECRET
Audience ID env var	RESEND_AUDIENCE_ID
Docs	resend.com/docs
Pricing	resend.com/pricing

Reference Index

I want to…	File
Install the SDK, initialize the client, and configure the API key	reference/setup.md
Send transactional emails with CC/BCC, tags, and scheduling	reference/send.md
Send up to 100 emails in one API call	reference/batch-send.md
Add file, URL, or inline image attachments	reference/attachments.md
Handle delivery events and verify webhook signatures	reference/webhooks.md
Manage contacts and audiences for marketing	reference/contacts.md
Handle errors, implement retry logic, and use idempotency keys	reference/error-handling.md

Usage: Read the reference file matching your current task from the index above. Each file is self-contained with code examples and inline gotchas.