> For the complete documentation index, see [llms.txt](https://docs.cekat.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cekat.ai/en/chat/broadcast-template-authentication-otp.md).

# Broadcast Template Authentication (OTP)

If you offer logins, account verification or OTP codes over WhatsApp, you'll need to use an **authentication template**. WhatsApp provides this template specifically to keep verification secure and efficient.

<figure><img src="https://3693109682-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZNZlvyOVkZXyd3pz2Cql%2Fuploads%2F7MXCNDTRcwbkfBWyEvM2%2F394147422_1358907818046981_8521054943438006496_n.webp?alt=media&#x26;token=895f84f5-c9e5-40c9-bbb8-15a27e4821cc" alt="" width="375"><figcaption></figcaption></figure>

### What is an authentication template?

An authentication template is a type of template message used to send **one-time verification codes (OTP)** to users. It comes with a **copy code button**, so users can copy their code with a single tap.

## How to use an authentication template

<figure><img src="https://3693109682-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FZNZlvyOVkZXyd3pz2Cql%2Fuploads%2FK6fHs4jRB7kegTAAIaUh%2FScreenshot%202025-05-22%20at%2011.41.51%E2%80%AFAM.png?alt=media&#x26;token=6541de70-be1e-431f-8bfc-e56eec78bedc" alt="" width="375"><figcaption></figcaption></figure>

### A. Creating an authentication template

1. Go to the Broadcast page
   * Open the **Broadcast** menu and choose the **Template** tab.
2. Create a new template
   * Click **Add Template** to create a new template.
3. Fill in the template data
   * Fill in the usual details (template name, language and so on).
   * Under **Category**, choose **Authentication**.
4. Set the authentication options
   * **Add Security Recommendation**:\
     When turned on (`true`), this adds a line such as: *"For your security, do not share this code."*
   * **OTP Button Text**:\
     The text on the copy OTP button, for example: *"Copy OTP"*
   * **Code Expiration Minutes (optional)**:\
     How long the OTP stays valid. If you leave it blank, no expiry information is shown.
   * **TTL Seconds (optional)**:\
     Time-to-live in seconds, which you can set as needed.

### B. Sending an authentication template (API)

You can send the template through the API using Postman, cURL or a similar tool, with the **POST** method.

* **Endpoint URL**:\
  `https://api.cekat.ai/templates/send`
* **Request body**:

```json
{
  "wa_template_id": "",
  "template_body_variables": [],
  "otp_code": "552345",
  "inbox_id": "",
  "phone_number": "",
  "phone_name": ""
}
```

#### Parameters:

* **wa\_template\_id**: the ID of the template you created. You'll find it on the template's detail page.
* **template\_body\_variables**: fill this in if your template uses variables in the body.
* **otp\_code**: the OTP code you want to send (up to 15 characters).
* **inbox\_id**: the ID of the WhatsApp inbox used to send the message. You can get it from the **GET inbox** endpoint.
* **phone\_number**: the recipient's phone number.
* **phone\_name**: the name linked to that number (optional, for display or logging).