# Managing contacts

> Add contacts to an audience with an email and optional name, track their subscribe state, and address them by id or email.

A **contact** is a single person on an audience. Contacts are nested under the audience that owns them — every contact operation runs against `/audiences/:audience_id/contacts`.

The only required field is `email`. You can optionally store a `first_name` and `last_name`, an `unsubscribed` flag that controls whether campaigns reach them, and a `properties` map of custom fields you can use to personalize campaigns.

## The contact object

```json
{
  "object": "contact",
  "id": "479e3145-dd0e-4f64-bf48-1d4b6d4cd8f6",
  "email": "steve@example.com",
  "first_name": "Steve",
  "last_name": "Wozniak",
  "unsubscribed": false,
  "properties": {
    "company_name": "Acme Corp"
  },
  "created_at": "2026-06-23T17:30:11.000Z"
}
```

Emails are stored lowercased. `first_name` and `last_name` are `null` when not provided. `properties` is always present and includes every registered custom property, merged with fallback values.

## Adding a contact

Send the `email` (required) plus any optional fields to the audience’s contacts collection. Alongside `first_name`, `last_name`, and `unsubscribed`, you can include a `properties` object of custom field values — each key must already be registered as a contact property on your account and the value must match its type.

**Node.js**

```js
import { SendPing } from 'sendping';

const mb = new SendPing('mb_xxxxxxxxx');

const { data, error } = await mb.contacts.create({
  audienceId: 'AUDIENCE_ID',
  "email": "steve@example.com",
  "first_name": "Steve",
  "last_name": "Wozniak",
  "unsubscribed": false
});
console.log({ data, error });
```

**Ruby**

```ruby
require 'net/http'
require 'uri'

uri = URI('https://www.sendping.co/api/audiences/AUDIENCE_ID/contacts')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
req = Net::HTTP::Post.new(uri)
req['Authorization'] = 'Bearer mb_xxxxxxxxx'
req['Content-Type'] = 'application/json'
req.body = <<~JSON
{
  "email": "steve@example.com",
  "first_name": "Steve",
  "last_name": "Wozniak",
  "unsubscribed": false
}
JSON
res = http.request(req)
puts res.body
```

**PHP**

```php
<?php
require 'vendor/autoload.php';

use SendPing\SendPing;

$sendping = SendPing::client('mb_xxxxxxxxx');

$sendping->contacts->create([
  'audienceId' => "AUDIENCE_ID",
  'email' => "steve@example.com",
  'first_name' => "Steve",
  'last_name' => "Wozniak",
  'unsubscribed' => false
]);
```

**Python**

```python
import requests

res = requests.post(
    "https://www.sendping.co/api/audiences/AUDIENCE_ID/contacts",
    headers={"Authorization": "Bearer mb_xxxxxxxxx", "Content-Type": "application/json"},
    json={
  "email": "steve@example.com",
  "first_name": "Steve",
  "last_name": "Wozniak",
  "unsubscribed": false
},
)
print(res.json())
```

**Go**

```go
import "github.com/shekhu10/sendping-sdks/sendping-go"

client := sendping.NewClient("mb_xxxxxxxxx")

contact, err := client.Contacts.Create(&sendping.CreateContactRequest{
    AudienceId:   "AUDIENCE_ID",
    Email:        "steve@example.com",
    FirstName:    "Steve",
    LastName:     "Wozniak",
    Unsubscribed: false,
})
```

**Rust**

```rust
use sendping::{CreateContactOptions, SendPing};

let mb = SendPing::new("mb_xxxxxxxxx");

let params = CreateContactOptions::new("steve@example.com")
    .with_audience_id("AUDIENCE_ID")
    .with_first_name("Steve")
    .with_last_name("Wozniak")
    .with_unsubscribed(false);
let _contact = mb.contacts.create(params).await?;
```

**Java**

```java
import co.sendping.SendPing;
import co.sendping.SendPingResponse;
import co.sendping.requests.CreateContactRequest;

SendPing sendping = new SendPing("mb_xxxxxxxxx");

CreateContactRequest request = CreateContactRequest.builder()
        .audienceId("AUDIENCE_ID")
        .email("steve@example.com")
        .firstName("Steve")
        .lastName("Wozniak")
        .unsubscribed(false)
        .build();

SendPingResponse response = sendping.contacts().create(request);
```

**.NET**

```csharp
using SendPing;

ISendPing sendping = SendPingClient.Create("mb_xxxxxxxxx");

var resp = await sendping.ContactCreateAsync(new ContactCreateOptions
{
    AudienceId = "AUDIENCE_ID",
    Email = "steve@example.com",
    FirstName = "Steve",
    LastName = "Wozniak",
    Unsubscribed = false,
});
```

**cURL**

```bash
curl -X POST 'https://www.sendping.co/api/audiences/AUDIENCE_ID/contacts' \
  -H 'Authorization: Bearer mb_xxxxxxxxx' \
  -H 'Content-Type: application/json' \
  -d '{
  "email": "steve@example.com",
  "first_name": "Steve",
  "last_name": "Wozniak",
  "unsubscribed": false
}'
```

## Upsert by email

Contacts are **unique by email within an audience**. If you create a contact whose email already exists in that audience, SendPing **merges** into the existing contact instead of creating a duplicate. This makes the create call safe to call repeatedly (for example, on every signup) without producing duplicates.

> **Note:** The merge never destroys data: an omitted `first_name`/`last_name` keeps the value already stored, `properties` are merged key by key (incoming keys win), and `unsubscribed` is monotonic — a create can suppress a contact but can never re-subscribe one, so sending `unsubscribed: false` for an opted-out contact leaves the opt-out in place. Use [PATCH](https://www.sendping.co/docs/api/contacts-update) to re-subscribe a contact or to clear a name.

## Addressing a contact by id or email

Anywhere a contact identifier appears in the path — get, update, delete — you can pass either the contact `id` or its `email`. SendPing detects which you provided. Both of these refer to the same contact:

```bash
GET https://www.sendping.co/api/audiences/AUDIENCE_ID/contacts/479e3145-dd0e-4f64-bf48-1d4b6d4cd8f6
GET https://www.sendping.co/api/audiences/AUDIENCE_ID/contacts/steve@example.com
```

## Contact properties

Every contact has four **default properties** — `email`, `first_name`, `last_name`, and `unsubscribed`. You can also register **custom properties** to store additional information (for example `company_name` or `plan`) and use those values to personalize campaigns. Properties are registered once per account with [POST /contact-properties](https://www.sendping.co/docs/audiences/properties) — there is no per-audience registry, so a registered key is valid for every contact in every audience.

Set custom values by passing a `properties` map when you create or [update](https://www.sendping.co/docs/api/contacts-update) a contact:

```json
{
  "email": "steve@example.com",
  "first_name": "Steve",
  "properties": {
    "company_name": "Acme Corp",
    "plan": "pro"
  }
}
```

> **Warning:** A property key must already be registered on your account and the value must match its declared type. On `POST /contacts` (and the audience-scoped `POST /audiences/:audience_id/contacts`) unknown keys or mismatched types are rejected and the contact is not changed. Property keys are case-sensitive — `company_name` and `companyName` are different keys.

## Bulk import by CSV

Upload a CSV up to **5 MB**, choose a segment, and review validation counts and the first 20 contacts before importing. The super-admin is exempt from the file-size limit. All plans have unlimited stored contacts. Overlapping imports merge by normalized email; segment membership is unique and existing unsubscribe preferences are preserved. The original CSV stays in private S3 storage; sending uses validated database contacts and current suppression preferences.

| on_conflict | Behavior |
| --- | --- |
| `upsert` | Update the existing contact with the values from the CSV row. |
| `skip` | Leave the existing contact untouched and skip the row. |

## Automatic creation

> **Note:** Contacts are also created automatically when an [automation](https://www.sendping.co/docs/automations/overview) runs for an email address that does not yet exist on the audience, so you do not have to pre-add every recipient.

## Next steps

- [Create a contact via the API](https://www.sendping.co/docs/api/contacts-create).
- [Update a contact](https://www.sendping.co/docs/api/contacts-update) — change a name, a property, or the subscribe state.
- [Manage unsubscribed contacts](https://www.sendping.co/docs/audiences/unsubscribed).