> For the complete documentation index, see [llms.txt](https://docs.sprinthub.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sprinthub.com/en/strategies/whatsapp/mention-on-whatsapp-what-it-is-how-it-works-and-how-to-use-it-in-sprinthub.md).

# @mention on WhatsApp – What it is, how it works, and how to use it in SprintHub

The **@lid (Linked ID)** is a unique, private identifier created by WhatsApp to represent users **without exposing the phone number**.\
This change is part of Meta's privacy updates and is being applied in a **gradual**, which means that:

* Not all users use @lid yet.
* The behavior may vary between chats, groups, and devices.
* Even if the user **has not hidden the number**, WhatsApp may send only the @lid.

Therefore, it is essential to adapt integrations — including SprintHub's — to handle this transition.

***

## **Difference between @lid and phone**

WhatsApp can now return the contact identifier in different ways:

#### **📌 `phone`**

May contain:

* The contact's actual number → `"554499999999"`
* Or the @lid itself → `"999999999999999@lid"`

In other words: **phone is no longer a guarantee of a phone number.**

***

#### **📌 `chatLid`**

It is the contact's most stable unique identifier.\
However, it can come as:

* A valid @lid
* Or `null`

When the `chatLid` comes as `null`, the field `phone` can return **only the @lid**.

➡️ The behavior is defined exclusively by WhatsApp — and may change at any time.

***

## **Webhook examples**

Depending on the account, privacy, and context, WhatsApp may send different identifiers.

#### **Example 1 — Full return with number and @lid**

```json
{
  "chatLid": "999999999999999@lid",
  "phone": "554499999999"
}
```

#### **Example 2 — Return with only @lid**

```json
{
  "chatLid": null,
  "phone": "65998849469@lid"
}
```

This behavior occurs when WhatsApp **hides the number** and provides only the @lid identifier.

SprintHub/Z-API only **exactly replicates** what WhatsApp sends.

***

## **Sending messages using @lid**

```json
{
  "phone": "999999999999999@lid",
  "message": "Hello! This message was sent using the @lid identifier."
}
```

Even without the real number, WhatsApp delivers the message normally.

***

## **Best implementation practices**

To avoid inconsistencies, we recommend:

#### **1. Prioritize using `@lid`**

It is more stable and tends to be the definitive identifier chosen by WhatsApp.

#### **2. Don't rely only on `phone`**

This field may contain:

* Real number
* @lid
* Mixed formats

#### **3. Always store the @lid in your database**

Treat the @lid as a permanent identifier.

#### **4. Keep an internal mapping between:**

* `chatLid`
* `phone` (when real number)
* @lid

This keeps your support, automation, and CRM logic consistent.

***

## **Conversion between number and @lid**

#### **❌ Convert @lid → number**

It's not possible.\
No API, not even WhatsApp's internal one, provides this information.

This exists **for privacy reasons**.

***

#### **✔️ Convert number → @lid**

This is possible using the Z-API endpoint **“Number with WhatsApp?”**, which checks:

* Whether the number exists on WhatsApp
* And returns the corresponding @lid, when available

This is the official way to obtain the identifier.

***

## **Important points**

* The @lid is a **native WhatsApp**, not SprintHub's or Z-API's.
* The behavior may change at any time, without prior notice.
* The attribute `chatLid` is already implemented in webhooks and can be used for sending.
* The change is being applied **gradually**, so results may be inconsistent across users, groups, and environments.