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Overview

The Email API allows you to send confirmation emails to attendees with personalized content, QR codes, and portal links. Emails are sent via the Resend service using edge functions.

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Send Confirmation Emails

Send confirmation emails to one or more attendees: 
const { data, error } = await supabase.functions.invoke('send-confirmation-email', {
  body: {
    attendee_ids: [
      '123e4567-e89b-12d3-a456-426614174001',
      '456e7890-e89b-12d3-a456-426614174002'
    ]
  }
})

if (error) {
  console.error('Error sending emails:', error)
} else {
  console.log('Emails sent:', data.sent)
  console.log('Emails failed:', data.failed)
}

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Request Body

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Response

{
  "results": [
    {
      "id": "123e4567-e89b-12d3-a456-426614174001",
      "success": true
    },
    {
      "id": "456e7890-e89b-12d3-a456-426614174002",
      "success": true
    }
  ],
  "sent": 2,
  "failed": 0
}
​
results
array
Array of result objects for each attendee
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sent
number
Total number of emails successfully sent
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failed
number
Total number of emails that failed to send

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Test Emails

Send a test email to verify your template before sending to attendees: 
const { data, error } = await supabase.functions.invoke('send-confirmation-email', {
  body: {
    attendee_ids: ['123e4567-e89b-12d3-a456-426614174001'],
    test_email_override: '[email protected]'
  }
})

if (!error) {
  console.log('Test email sent to [email protected]')
}
When test_email_override is provided, all emails will be sent to that address instead of the attendee’s actual email. The subject line will be prefixed with “[TEST]”.

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Email Template Variables

Customize email content using template variables in your event’s confirmation_email_content:

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Email Template Example

<h2>Hi {{name}},</h2>
<p>You're confirmed for <strong>{{event_name}}</strong>!</p>

<p>
  <strong>Date:</strong> {{event_date}}<br/>
  <strong>Venue:</strong> {{event_venue}}
</p>

<p>
  Your unique check-in ID is: 
  <strong style="font-family: monospace; font-size: 18px; letter-spacing: 2px;">
    {{unique_id}}
  </strong>
</p>

<p>Show this QR code at the entrance for quick check-in:</p>
<p>
  <img src="{{qr_code_url}}" alt="QR Code" width="200" height="200" />
</p>

<p>
  <a href="{{portal_url}}" style="display: inline-block; padding: 12px 24px; background: #0066cc; color: white; text-decoration: none; border-radius: 4px;">
    View Your Attendee Portal →
  </a>
</p>

<p>See you there!</p>

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Set Email Template

Update the email template for an event: 
const emailTemplate = `
  <h2>Hi {{name}},</h2>
  <p>You're confirmed for <strong>{{event_name}}</strong>!</p>
  <p><strong>Date:</strong> {{event_date}}<br/><strong>Venue:</strong> {{event_venue}}</p>
  <p>Your unique check-in ID is: <strong style="font-family: monospace; font-size: 18px; letter-spacing: 2px;">{{unique_id}}</strong></p>
  <p>Show this QR code at the entrance for quick check-in:</p>
  <p><img src="{{qr_code_url}}" alt="QR Code" width="200" height="200" /></p>
  <p><a href="{{portal_url}}">View your attendee portal →</a></p>
  <p>See you there!</p>
`

const { error } = await supabase
  .from('events')
  .update({ confirmation_email_content: emailTemplate })
  .eq('id', eventId)

if (error) {
  console.error('Error updating template:', error)
} else {
  console.log('Email template updated')
}

​
Bulk Email Sending

Send emails to all attendees who haven’t received one: 
// Get attendees without confirmation emails
const { data: attendees } = await supabase
  .from('attendees')
  .select('id')
  .eq('event_id', eventId)
  .eq('confirmation_email_sent', false)

if (attendees && attendees.length > 0) {
  const attendeeIds = attendees.map(a => a.id)
  
  // Send emails in batches of 50
  const batchSize = 50
  for (let i = 0; i < attendeeIds.length; i += batchSize) {
    const batch = attendeeIds.slice(i, i + batchSize)
    
    const { data, error } = await supabase.functions.invoke('send-confirmation-email', {
      body: { attendee_ids: batch }
    })
    
    if (error) {
      console.error(`Batch ${i / batchSize + 1} failed:`, error)
    } else {
      console.log(`Batch ${i / batchSize + 1}: ${data.sent} sent, ${data.failed} failed`)
    }
    
    // Wait 1 second between batches to avoid rate limits
    if (i + batchSize < attendeeIds.length) {
      await new Promise(resolve => setTimeout(resolve, 1000))
    }
  }
}

​
Email Status Tracking

Check which attendees have received confirmation emails: 
const { data: stats } = await supabase
  .from('attendees')
  .select('confirmation_email_sent')
  .eq('event_id', eventId)

if (stats) {
  const sent = stats.filter(a => a.confirmation_email_sent).length
  const pending = stats.length - sent
  
  console.log(`Emails sent: ${sent} / ${stats.length}`)
  console.log(`Pending: ${pending}`)
}

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Get Attendees Without Emails

Retrieve attendees who haven’t received confirmation emails: 
const { data: pending } = await supabase
  .from('attendees')
  .select('id, name, email, unique_id')
  .eq('event_id', eventId)
  .eq('confirmation_email_sent', false)

if (pending) {
  console.log(`${pending.length} attendees pending email`)
  pending.forEach(a => {
    console.log(`${a.name} (${a.email})`)  
  })
}

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Email Audit Logging

The send-confirmation-email function automatically logs email sending activity: 
// Audit logs are created automatically
// View them from the audit_logs table
const { data: logs } = await supabase
  .from('audit_logs')
  .select('*')
  .eq('action', 'sent_confirmation_emails')
  .eq('entity_type', 'event')
  .eq('entity_id', eventId)
  .order('created_at', { ascending: false })

if (logs) {
  logs.forEach(log => {
    const details = log.details as any
    console.log(`${log.created_at}: Sent ${details.sent}, Failed ${details.failed}`)
  })
}

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Email Layout

Emails are automatically wrapped in a responsive layout with your organization branding: 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
</head>
<body style="margin:0; padding:0; background-color:#f4f4f5; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;">
  <div style="max-width:600px; margin:0 auto; padding:24px;">
    <div style="background:#ffffff; border-radius:0; padding:32px; border:1px solid #e4e4e7;">
      <!-- Your email content here -->
    </div>
    <div style="text-align:center; padding:16px; color:#71717a; font-size:12px;">
      <p>Your Organization — Powered by PassTru</p>
    </div>
  </div>
</body>
</html>

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QR Code Generation

QR codes are generated using the QR Server API: 
const uniqueId = 'K7M9P2Q5'
const qrCodeUrl = `https://api.qrserver.com/v1/create-qr-code/?size=200x200&data=${encodeURIComponent(uniqueId)}`

// This URL is automatically included in emails as {{qr_code_url}}

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Error Handling

Common email sending errors:
  • Unauthorized: User doesn’t have access to the event
  • Invalid attendee IDs: UUIDs are malformed
  • No attendees found: Attendee IDs don’t exist
  • Resend API error: Service unavailable or rate limited
const { data, error } = await supabase.functions.invoke('send-confirmation-email', {
  body: { attendee_ids: attendeeIds }
})

if (error) {
  console.error('Email sending error:', error.message)
  
  // Check for specific errors
  if (error.message.includes('Unauthorized')) {
    console.error('You do not have permission to send emails for this event')
  } else if (error.message.includes('Invalid attendee_ids')) {
    console.error('One or more attendee IDs are invalid')
  } else {
    console.error('An unexpected error occurred')
  }
} else {
  // Check individual results
  data.results.forEach(result => {
    if (!result.success) {
      console.error(`Failed to send email to attendee ${result.id}: ${result.error}`)
    }
  })
}

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Rate Limits

Resend API limits (free tier):
  • 100 emails per day
  • 3,000 emails per month
  • Upgrade to paid plans for higher limits
To avoid rate limits, send emails in batches with delays between batches. See the “Bulk Email Sending” example above.

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Security

The email function includes security measures:
  1. Authentication required: User must be signed in
  2. Authorization checks: User must own or be assigned to the event
  3. Input validation: Attendee IDs and email addresses are validated
  4. HTML escaping: User data is escaped to prevent injection
  5. Test mode: Use test_email_override to avoid sending to real users during testing

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Next Steps

Attendees API

Manage attendees and their data

Check-ins API

Handle check-ins at your event

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