Email sign-in

Supabase’s built-in email only reaches your project’s own team members, 2 an hour, so email sign-in needs an email service over SMTP. Resend has a free tier, and Postmark, Amazon SES or your mail provider’s SMTP work the same way.

With Resend

1. In Resend, add and verify a domain you own, such as mail.example.com.

2. Create an API key with Sending access, restricted to that domain.

3. In Supabase, open Authentication → Emails → SMTP Settings, turn on Enable custom SMTP, and fill in:

   Field	Value
   Sender email	an address on your domain, such as login@mail.example.com
   Sender name	squad-chat
   Host	smtp.resend.com
   Port	465
   Username	resend
   Password	the Resend API key

4. Under Authentication → Emails → Templates, edit Confirm signup and Magic Link so they show the code. For example, subject Your squad-chat code and body:

   <h2>squad-chat</h2>
   <p>Your sign-in code:</p>
   <p style="font-size:28px;font-weight:bold;letter-spacing:4px">{{ .Token }}</p>
   <p>Type it into Claude Code. It expires in one hour.</p>

5. Try it: sign in with your own email. Each code shows up under Emails in Resend’s dashboard, with its delivery status.

Note

New free Supabase projects can only change their email templates once custom SMTP is set up, so do step 3 before step 4.