1import { Resend } from 'resend';
2
3const resend = new Resend('re_xxxxxxxxx');
4
5// Define custom contact properties for usage-based segmentation
6const { data: usageProperty, error: usageError } = await resend.contactProperties.create({
7  key: 'usagePercentage',
8  type: 'string',
9  fallbackValue: '0%',
10});
11
12const { data: planProperty, error: planError } = await resend.contactProperties.create({
13  key: 'planTier',
14  type: 'string',
15  fallbackValue: 'free',
16});
17
18// Create contact with custom properties for segmentation
19const { data, error } = await resend.contacts.create({
20  email: 'customer@example.com',
21  firstName: 'John',
22  lastName: 'Doe',
23  unsubscribed: false,
24});

{
  "object": "contact_property",
  "id": "b6d24b8e-af0b-4c3c-be0c-359bbd97381e"
}

1// Reuse resend instance and contact from Section 1
2// data and error are already defined from Section 1's resend.contacts.create call
3
4if (!error && data) {
5  // Add contact to segment based on usage threshold
6  await resend.contacts.segments.add({
7    contactId: data.id,
8    segmentId: '78261eea-8f8b-4381-83c6-79fa7120f1cf',
9  });
10}

1// Reuse resend instance from Section 1
2// Create broadcasts targeting segments by usage threshold
3
4// Define segment for 80% usage threshold
5const segment80 = await resend.broadcasts.create({
6  segmentId: '78261eea-8f8b-4381-83c6-79fa7120f1cf',
7  from: 'Billing <alerts@resend.dev>',
8  subject: 'Usage Alert: 80% of your monthly quota reached',
9  html: 'Hi {{{contact.firstName|there}}}, your account is at 80% usage. Review your plan: {{{RESEND_UNSUBSCRIBE_URL}}}',
10});
11
12// Define segment for 95% usage threshold
13const segment95 = await resend.broadcasts.create({
14  segmentId: '78261eea-8f8b-4381-83c6-79fa7120f1cf',
15  from: 'Billing <alerts@resend.dev>',
16  subject: 'Critical Alert: 95% of your monthly quota reached',
17  html: 'Hi {{{contact.firstName|there}}}, your account is at 95% usage. Upgrade now: {{{RESEND_UNSUBSCRIBE_URL}}}',
18});

{
  "object": "contact",
  "id": "479e3145-dd38-476b-932c-529ceb705947"
}

1// Reuse resend instance from Section 1
2// Send targeted billing alerts to contacts based on usage thresholds
3
4// Add contacts to 80% threshold segment
5await resend.contacts.segments.add({
6  email: 'customer@example.com',
7  segmentId: '80-percent-threshold-segment-id',
8});
9
10// Create and send 80% upgrade invitation broadcast
11const { data: broadcast80 } = await resend.broadcasts.create({
12  segmentId: '80-percent-threshold-segment-id',
13  from: 'Billing <billing@company.com>',
14  subject: 'Usage Alert: Time to Upgrade?',
15  html: 'Hi {{{contact.firstName|there}}}, you\'re at 80% of your usage limit. Upgrade now to avoid disruptions. {{{RESEND_UNSUBSCRIBE_URL}}}',
16  send: true,
17});
18
19// Add contacts to 95% threshold segment
20await resend.contacts.segments.add({
21  email: 'customer@example.com',
22  segmentId: '95-percent-threshold-segment-id',
23});
24
25// Create and send 95% overage warning broadcast
26const { data: broadcast95 } = await resend.broadcasts.create({
27  segmentId: '95-percent-threshold-segment-id',
28  from: 'Billing <billing@company.com>',
29  subject: 'Urgent: Usage Limit Nearly Exceeded',
30  html: 'Hi {{{contact.firstName|there}}}, you\'re at 95% of your usage limit. Overages will apply within 24 hours. Upgrade immediately. {{{RESEND_UNSUBSCRIBE_URL}}}',
31  send: true,
32});

1// Section 5: Monitor and refresh contacts as usage updates to keep alerts in sync
2// Uses resend instance, data (contact), broadcast80, and broadcast95 from prior sections
3
4// Log current broadcast statuses for monitoring
5console.log('80% threshold broadcast:', broadcast80);
6console.log('95% threshold broadcast:', broadcast95);
7
8// Log contact id for reference when refreshing usage properties
9if (data) {
10  console.log('Tracking contact id:', data.id);
11}