# @lid on WhatsApp – What it is, how it works, and how to handle it in SprintHub

The **@lid (Linked ID)** is a unique and 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 **gradually**, which means that:

* Not all users use @lid yet.
* 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**

Today WhatsApp can return the contact identifier in different ways:

#### **📌 `phone`**

May contain:

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

That is: **phone is no longer a guarantee of a phone number.**

***

#### **📌 `chatLid`**

Is the contact's most stable unique identifier.\
However, it may come as:

* A valid @lid
* Or `null`

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

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

***

## **Webhook examples**

Depending on the account, privacy settings 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 **replicates exactly** what WhatsApp sends.

***

## **Sending messages using the @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.

***

## **Implementation best practices**

To avoid inconsistencies, we recommend:

#### **1. Prioritize the use of `@lid`**

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

#### **2. Do not rely solely 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 internal mapping between:**

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

This way your customer service logic, automations and CRM remain consistent.

***

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

#### **❌ Convert @lid → number**

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:

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

This is the official way to obtain the identifier.

***

## **Important points**

* @lid is a **native WhatsApp**feature, not SprintHub's or Z-API's.
* Behavior can 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.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.sprinthub.com/en/strategies/whatsapp/lid-on-whatsapp-what-it-is-how-it-works-and-how-to-handle-it-in-sprinthub.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.