Supabase + Resend Integration Guide
Resend is the developer-first email API that integrates natively with Supabase. You can send transactional emails — welcome emails, password resets, notifications, invoices — from Supabase edge functions triggered by database changes or auth events, with React-based email templates and excellent deliverability.
Why Supabase + Resend?
Resend was built by ex-Supabase team members and integrates seamlessly with the platform. Unlike older email services, Resend has a clean REST API, supports React email templates (JSX-based responsive email design), and provides excellent deliverability out of the box. For Supabase apps, it's the recommended email provider for transactional emails beyond the basic auth emails that Supabase sends natively.
Setting up the integration
Create a Resend account, verify your domain (adds SPF, DKIM, DMARC records to your DNS), and generate an API key. Store the key as a Supabase secret: supabase secrets set RESEND_API_KEY=re_xxx. Create a Supabase edge function that calls Resend's POST /emails endpoint with your from address, recipient, subject, and HTML or React template. Trigger this function from database webhooks (on INSERT/UPDATE), auth hooks, or directly from your frontend via an authenticated edge function call.
Email trigger patterns
Common Supabase + Resend patterns: user created in auth.users → edge function → welcome email via Resend; order status updated in orders table → database webhook → edge function → status notification email; subscription cancelled in subscriptions table → webhook → retention email; support ticket created → edge function → confirmation email to user + notification to support team. These patterns replace the need for a dedicated email service like Mailchimp for transactional flows.
Real-world use cases
App Studio uses Supabase + Resend for all transactional email needs on production apps: onboarding sequences triggered by user milestones, invoice emails generated from Supabase data and sent via Resend, alert emails for critical database events, and digest emails assembled from weekly database aggregations. Resend's email analytics dashboard shows opens, clicks, and bounces per recipient.
Common pitfalls
Always verify your sending domain before going to production — emails sent from unverified domains land in spam. Store your Resend API key as a Supabase secret, never in edge function source code. Implement idempotency checks: if your database webhook fires twice for the same event (Supabase guarantees at-least-once delivery), your edge function should check if the email was already sent before calling Resend. Use Resend's test mode to preview emails without actually sending them during development.
What you can build
- Welcome emails
- Order confirmations
- Password resets
- Invoice emails
- Event-driven notifications
Ready to build with Supabase + Resend?
App Studio has built production apps on this exact stack. We can ship your project in 4–8 weeks and handle the full integration — architecture, setup, and launch.
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