# How to Attach a Link

Add a URL link attachment to an existing message. You can include multiple links in one request.

```
POST /messages/{message_id}/attachments
Content-Type: application/json
```

```json
{
  "attachments": [
    {
      "type": "link",
      "link": "https://example.com"
    }
  ]
}
```

The `message_id` is returned in the response from [`POST /v3/messages/start`](./how-to-send-a-message.md).