---
title: Contacts
description: Manage your audience at scale
---

## What are contacts

Contacts are people in your audience. Each contact has an email address, subscription status, and custom data fields you define. Use contacts to personalize emails, build segments, and track engagement.

## Creating contacts

### Add a single contact

```bash
curl -X POST {{API_URL}}/contacts \
  -H "Authorization: Bearer sk_your_secret_key" \
  -H "Content-Type: application/json" \
  -d '{
    "email": "user@example.com",
    "subscribed": true,
    "data": {
      "firstName": "Sarah",
      "plan": "pro",
      "signupDate": "2024-03-15"
    }
  }'
```

### Automatic upsert

If the email already exists, the contact is updated instead of creating a duplicate:

```javascript
// First call - creates contact
POST /contacts { email: 'user@example.com', data: { plan: 'free' } }

// Second call - updates same contact
POST /contacts { email: 'user@example.com', data: { plan: 'pro' } }

// Result: One contact with plan: 'pro'
```

This is useful when syncing user data from your application.

## Contact data fields

Store custom data in the `data` field. Use it for:

- User profile (name, company, role)
- Subscription info (plan, MRR, renewal date)
- Behavior tracking (last login, feature usage)
- Preferences (newsletter, notifications)

**Example:**

```json
{
  "email": "user@example.com",
  "subscribed": true,
  "data": {
    "firstName": "Sarah",
    "lastName": "Chen",
    "company": "Acme Inc",
    "plan": "premium",
    "mrr": 99,
    "lastLoginAt": "2024-03-15T10:30:00Z",
    "preferences": {
      "newsletter": true,
      "productUpdates": false
    }
  }
}
```

### Best practices

**Use consistent naming** — Pick camelCase or snake_case and stick with it.

**Store dates as ISO strings** — `"2024-03-15T10:30:00Z"` enables date range filtering in segments.

**Keep it relatively flat** — Nested objects work, but flat structures are easier to query in segments.

**Use numbers for numeric data** — Store `99` not `"99"` to enable greater than/less than comparisons.

## Using contact data in emails

### Template variables

Access contact data in email templates using `{{variableName}}` syntax:

```html
<h1>Hello {{firstName}}!</h1>
<p>Your {{plan}} plan renews on {{renewalDate}}.</p>
<p>Total: ${{mrr}}</p>
```

When sending, contact data automatically populates variables:

```bash
curl -X POST {{API_URL}}/v1/send \
  -H "Authorization: Bearer sk_your_secret_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "subject": "Renewal reminder",
    "body": "<p>Hi {{firstName}}, your {{plan}} plan renews soon.</p>"
  }'
```

The `firstName` and `plan` values come from the contact's `data` field.

### Fallback values

Provide defaults when data might be missing:

```html
<p>Hello {{firstName ?? 'there'}}!</p>
<p>Plan: {{plan ?? 'Free'}}</p>
```

If `firstName` is not set, displays "Hello there!" instead of blank.

### Passing additional data

Send extra data for a specific email without saving it to the contact:

```bash
curl -X POST {{API_URL}}/v1/send \
  -H "Authorization: Bearer sk_your_secret_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "user@example.com",
    "subject": "Your verification code",
    "body": "<p>Your code: {{verificationCode}}</p>",
    "data": {
      "verificationCode": "ABC123"
    }
  }'
```

The `verificationCode` is used in the email but not saved to the contact. This is useful for:
- One-time codes (password reset, verification)
- Session-specific data
- Temporary discount codes
- Order-specific details

### Reserved variables

These are always available in templates:

- `{{email}}` — Contact email address
- `{{id}}` — Contact ID

Example:
```html
<p>Your account: {{email}}</p>
<p><a href="https://app.example.com/contacts/{{id}}">Manage preferences</a></p>
```

## Listing contacts

### Get all contacts

```bash
curl -X GET "{{API_URL}}/contacts?limit=50" \
  -H "Authorization: Bearer sk_your_secret_key"
```

Returns:

```json
{
  "success": true,
  "data": {
    "items": [...],
    "nextCursor": "abc123",
    "hasMore": true,
    "total": 10000
  }
}
```

### Pagination

For large lists, use cursor-based pagination:

```javascript
let allContacts = [];
let cursor = null;

do {
  const params = new URLSearchParams({ limit: 100 });
  if (cursor) params.append('cursor', cursor);

  const response = await fetch(`{{API_URL}}/contacts?${params}`, {
    headers: { 'Authorization': `Bearer ${PLUNK_SECRET_KEY}` }
  });

  const { data } = await response.json();
  allContacts.push(...data.items);
  cursor = data.nextCursor;
} while (cursor);
```

### Filter by subscription

```bash
# Only subscribed
curl -X GET "{{API_URL}}/contacts?subscribed=true" \
  -H "Authorization: Bearer sk_your_secret_key"

# Only unsubscribed
curl -X GET "{{API_URL}}/contacts?subscribed=false" \
  -H "Authorization: Bearer sk_your_secret_key"
```

### Search by email

```bash
curl -X GET "{{API_URL}}/contacts?search=sarah" \
  -H "Authorization: Bearer sk_your_secret_key"
```

Searches for emails containing "sarah".

## Getting a contact

### By ID

```bash
curl -X GET {{API_URL}}/contacts/contact_id \
  -H "Authorization: Bearer sk_your_secret_key"
```

## Updating contacts

### Update contact data

```bash
curl -X PATCH {{API_URL}}/contacts/contact_id \
  -H "Authorization: Bearer sk_your_secret_key" \
  -H "Content-Type: application/json" \
  -d '{
    "subscribed": true,
    "data": {
      "plan": "premium",
      "mrr": 99
    }
  }'
```

### Data merging

Updates merge with existing data:

```javascript
// Current contact data
{ "firstName": "Sarah", "company": "Acme" }

// Update with
{ "lastName": "Chen", "plan": "pro" }

// Result
{ "firstName": "Sarah", "company": "Acme", "lastName": "Chen", "plan": "pro" }
```

To remove a field, set it to `null`.

### Change subscription status

```bash
curl -X PATCH {{API_URL}}/contacts/contact_id \
  -H "Authorization: Bearer sk_your_secret_key" \
  -H "Content-Type: application/json" \
  -d '{"subscribed": false}'
```

**Marketing templates** only send to subscribed contacts. **Transactional templates** send to everyone, regardless of subscription status.

## Deleting contacts

```bash
curl -X DELETE {{API_URL}}/contacts/contact_id \
  -H "Authorization: Bearer sk_your_secret_key"
```

**Warning:** Deletion is permanent. Consider unsubscribing instead of deleting.

## Bulk operations

### Import from CSV

Prepare a CSV file:

```csv
email,firstName,lastName,plan
sarah@example.com,Sarah,Chen,pro
john@example.com,John,Doe,free
```

Upload via dashboard:
1. Go to **Contacts**
2. Click **Import CSV**
3. Upload file
4. Map columns
5. Set default subscription status
6. Import

The import runs in the background. You'll receive a summary when complete.

## Available fields

### Get all custom fields

See what data fields your contacts have:

```bash
curl -X GET {{API_URL}}/contacts/fields \
  -H "Authorization: Bearer sk_your_secret_key"
```

Returns unique field names across all contacts:

```json
{
  "fields": [
    "firstName",
    "lastName",
    "company",
    "plan",
    "mrr",
    "signupDate"
  ]
}
```

### Get field values

See all unique values for a specific field:

```bash
curl -X GET {{API_URL}}/contacts/fields/plan/values \
  -H "Authorization: Bearer sk_your_secret_key"
```

Returns:

```json
{
  "values": ["free", "pro", "premium", "enterprise"]
}
```

Useful for building segment filters and understanding your data.

## Syncing with your app

Keep contacts in sync with your user database:

```javascript
// When user signs up
async function onUserSignup(user) {
  await fetch('{{API_URL}}/contacts', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${PLUNK_SECRET_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      email: user.email,
      subscribed: true,
      data: {
        firstName: user.firstName,
        lastName: user.lastName,
        signupDate: new Date().toISOString()
      }
    })
  });
}

// When user updates profile
async function onUserUpdate(user) {
  await fetch(`{{API_URL}}/contacts/${user.contactId}`, {
    method: 'PATCH',
    headers: {
      'Authorization': `Bearer ${PLUNK_SECRET_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      data: {
        firstName: user.firstName,
        lastName: user.lastName,
        company: user.company
      }
    })
  });
}

// When user subscribes to plan
async function onSubscriptionChange(user, plan, mrr) {
  await fetch(`{{API_URL}}/contacts/${user.contactId}`, {
    method: 'PATCH',
    headers: {
      'Authorization': `Bearer ${PLUNK_SECRET_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      data: {
        plan,
        mrr,
        subscriptionDate: new Date().toISOString()
      }
    })
  });
}
```

## Best practices

**Sync critical data only** — Don't sync every field. Focus on data used in segments, workflows, and personalization.

**Use webhooks for real-time sync** — Update contacts immediately when user data changes.

**Track subscription separately** — Use the `subscribed` field for email preferences, not app subscription status.

**Clean your list regularly** — Remove or unsubscribe bounced and inactive contacts.

**Respect opt-outs** — When users unsubscribe, update immediately. Don't re-subscribe them automatically.

**Test with real emails** — Use your own email addresses to test the contact experience.

## Next Steps

- [Build segments](/guides/segments) to group contacts
- [Send campaigns](/guides/campaigns) to your contacts
- [Track events](/guides/events) to update contact data automatically